[HN Gopher] Maximizing Battery Storage Profits via High-Frequenc...
       ___________________________________________________________________
        
       Maximizing Battery Storage Profits via High-Frequency Intraday
       Trading
        
       Author : doener
       Score  : 278 points
       Date   : 2025-06-12 09:43 UTC (1 days ago)
        
 (HTM) web link (arxiv.org)
 (TXT) w3m dump (arxiv.org)
        
       | dachworker wrote:
       | I'm not at all familiar with this whole field, but why would you
       | publish a trading strategy if it has potential? Why not sell it
       | to a hedgefund, at least? Or is this research formally publishing
       | what industry is already doing?
        
         | h4kor wrote:
         | This isn't a trade "just on paper". You need real hardware
         | integrated into the grid.
        
         | throw-qqqqq wrote:
         | Seemingly profitable strategies are actually published all the
         | time in finance literature.
         | 
         | Some also work (usually only for a short amount of time if
         | profitable), most don't really work at all for various
         | technical reasons (lookahead bias, model doesn't account for
         | slip/trading costs or assume infinite liquidity or a portfolio
         | too large to realistically rebalance etc.) and some again work,
         | but have unfavorable risk-adjusted return profiles compared to
         | simpler strategies.
        
           | yxhuvud wrote:
           | Or in the case of batteries: Requires a whole lot of hardware
           | to be bought to get a reasonable economy of scale.
        
             | throw-qqqqq wrote:
             | True and batteries have their own characteristics.
             | 
             | They do not last forever, have inefficiency/loss (order(s)
             | of magnitude larger than slippage/fees) etc.
             | 
             | It can seem like the Wild West with many opportunities for
             | arbitrage, but there are practical challenges.
             | 
             | Many countries prefer to improve energy infrastructure
             | through private initiatives, and this is one of the
             | incentives as I see it:
             | 
             | If you get a foothold, profitable trades can be made with
             | only limited competition.
             | 
             | This should also help decrease volatility of electricity-
             | prices, as predictable fluctuations gets evened out from
             | arbitrageurs.
        
         | Gys wrote:
         | Is the trading strategy making substantial returns (at least a
         | few percent) on the full investment (batteries, electronics,
         | subscriptions)? Otherwise this is only relevant for battery
         | owners that benefit already by other means (using the battery
         | at night for home owners, for example).
        
         | Energiekomin wrote:
         | The authors are from universities. Publicly funded.
         | 
         | And its not like they can just do that and get rich. Its
         | particular for/with battery storage systems.
         | 
         | Basically making battery storage systems more interesting for
         | investors to invest into.
        
         | loehnsberg wrote:
         | There's still a lot of work left to do to go from an academic
         | prototype to live trading: real-time data, market access,
         | SCADA, compliance & legal, security, ... Also you must be a
         | physical player that owns the battery and/or right to use it
         | and not just do paper trading.
        
           | 7thaccount wrote:
           | There is "virtual" (paper) trading in the day ahead markets
           | in the US, but it's just for amounts of energy. You can't
           | make a fake battery for the grid operator to optimize.
        
         | chardz wrote:
         | On top of what others have mentioned, this paper also sidesteps
         | forecasting electricity prices, which is already a very
         | complicated problem (particularly in U.S markets where we have
         | zonal pricing) needed to build profitable battery systems that
         | actually operate on the grid.
         | 
         | I've had a few chats with some folks working on battery
         | startups, and I think the more conventional approach is to
         | forecast prices + run an optimization to find optimal storage
         | decisions. You could measure the system's performance by
         | looking at how well the algorithm does when it has perfect
         | information about prices (obviously, when you have perfect
         | information about prices it is trivial to optimize the
         | battery).
        
           | dschaurecker wrote:
           | Our two follow-up papers are addressing exactly this (for
           | Europe)! We are extending our high-frequency continuous
           | intraday approach (CID) with a forecast-based day-ahead
           | bidding stage, and subsequent CID forecast updates.
           | 
           | I'd also be quite interested in strategies for grid-scale
           | BESS trading in the US' real-time markets. Do you know more
           | about it, or could forward me to someone who would be willing
           | to talk about it? ;)
        
             | chardz wrote:
             | I'm afraid I'm not too familiar with BESS in particular,
             | and the people I spoke to are probably not too keen on
             | sharing much (which is generally true of those who work in
             | U.S markets). Unfortunately it's all very opaque.
             | 
             | I'd be happy to provide you the names of the firms I spoke
             | to over email, if that would be of use!
        
               | dschaurecker wrote:
               | Yes thank you, that would be at least slightly more
               | refined than me just randomly writing companies which
               | might be relevant! My email is dschaurecker(at)gmail.com,
               | thanks again :)
        
         | dschaurecker wrote:
         | Most real-world optimizations for flexible storage assets
         | currently work across multiple markets, sometimes also with
         | more sophisticated boundary conditions. What we show is that
         | high-frequency trading on the continuous intraday market is
         | relevant, especially when training for more optimal
         | parametrized strategies.
         | 
         | It also seems like a sensible idea to publish details and
         | theories about an idea, not necessarily a finished trading
         | product though ;)
        
         | mhh__ wrote:
         | 1) It doesn't actually work
         | 
         | 2) It's worth more to your career
         | 
         | 3) Selling a strategy to a hedge fund as a stranger is, unless
         | they hire you, probably a good few months of umming and ahhing
         | and paperwork.
        
       | buu700 wrote:
       | This sounds similar to something I suggested at one point:
       | https://news.ycombinator.com/item?id=38669706
       | 
       |  _Imagine software that could run on EVs, Powerwall-type
       | batteries, computers /tablets/smartphones, and so on, which would
       | automatically charge and discharge for passive income.
       | Essentially algorithmic trading, but with power instead of stock.
       | You'd just have to configure any necessary time ranges and charge
       | percentages, e.g. maybe your EV needs to be at 25% by 8am and
       | again by 5pm on weekdays in order to make your daily commute._
       | 
       |  _Maybe some EVs will start to come with built-in crypto miners
       | to burn negatively priced power when the battery is at capacity.
       | Maybe Lyft /Uber and Waymo/Cruise will take advantage of it by
       | increasing and lowering rates based on the price of power (if
       | they don't already)._
        
         | Energiekomin wrote:
         | Thats what bi-directional charging is for and its already
         | becoming political to force the industry to support this.
         | 
         | And we already have energy provider which provide a tarif for
         | exactly this.
         | 
         | The only idea i hate is the mentioning of crypto. Not only is
         | it waste, it converts the energy in heat which needs to get
         | disipated and potentially wastes even more energy to get this
         | heat away from the current location (ac).
        
         | 7thaccount wrote:
         | Sorry to be the bearer of bad news, but this isn't novel and
         | something that's been talked about for a long time. The
         | industry term I've most heard is "prices to devices". You of
         | course need retail to participate more in the wholesale
         | markets, but there are a lot of barriers - some technological,
         | some regulatory. Some companies did this in ERCOT, but there
         | was a big backlash when customers got $20k bills after Winter
         | Storm Uri as they didn't understand what they were signing up
         | for.
         | 
         | The FERC passed Order 2222 which is a bigger step in that
         | direction by forcing the regional wholesale markets to allow
         | aggregators to aggregate up the smaller stuff that is normally
         | considered noise.
        
           | buu700 wrote:
           | Interesting, thanks. That doesn't sound like bad news at all.
        
             | 7thaccount wrote:
             | No I guess not. It can sometimes be a little sad though
             | when you think you've come up with some grand new idea and
             | it's been done.
        
           | infecto wrote:
           | And while not making money, there has been a lot of talk
           | around Virtual Power Plants, that is unifying the larger
           | demand devices to help stabilize the grid in times of peak
           | demand.
        
             | 7thaccount wrote:
             | Virtual Power Plants (VPPs) are essentially the same thing
             | as the Distributed Energy Resource Aggregators (DERAs) I
             | mentioned above. I guess a VPP is technically a more
             | general term and could also refer to the same concept under
             | different structures like in a micro grid.
             | 
             | The industry has a ton of jargon (literally thousands of
             | acronyms amongst the US regional markets) and in many cases
             | there are 8 terms that mean the exact same thing.
        
               | infecto wrote:
               | Not sure I follow but seems like a weird thing to
               | mention. The DERA is the who, the VPP is the what.
               | Similar but far from essentially the same thing.
        
               | 7thaccount wrote:
               | The DERA is frequently discussed as being both the market
               | entity as well as the collective what. Language is weird.
        
               | infecto wrote:
               | To be honest I cannot even understand what you are
               | saying. DERA is the who. VPP is the what.
        
               | 7thaccount wrote:
               | I'm saying the language isn't so cut and dry. People
               | commonly refer to both the who and the what (to use your
               | terms) as the DERA.
        
           | Dylan16807 wrote:
           | > Some companies did this in ERCOT, but there was a big
           | backlash when customers got $20k bills after Winter Storm Uri
           | as they didn't understand what they were signing up for.
           | 
           | It would be a bit weird but you could have your home supply
           | at a fixed-ish rate and your EV on a separate meter riding
           | the raw market.
           | 
           | If you can prevent too much cheating.
        
         | datadrivenangel wrote:
         | I wrote a book on this in 2020 and was already somewhat late to
         | the party, as people were running actual pilot programs a
         | decade earlier!
         | 
         | Also large industrial consumers have been participating in
         | similar approaches for decades. See the crazy clever trading
         | schemes that Enron used to do fraud and drive up prices.
        
         | bfayers wrote:
         | I run predbat (https://springfall2008.github.io/batpred/) to
         | achieve something like this with my Home Assistant install to
         | manage my home battery. It can also manage EV charging but I
         | haven't needed to do that yet due to how my tariff works. (Very
         | cheap fixed period overnight).
        
         | rtuin wrote:
         | This type of service is becoming increasingly prevalent among
         | European energy suppliers for their residential customers.
         | Beyond providing a revenue stream for consumers this model
         | aggregates distributed energy resources (home batteries, EV's,
         | PV systems) into a one virtual power plant. This enables the
         | storage of surplus energy generated during solar peaks and
         | dispatch back to the grid during periods of high demand. I find
         | it a fascinating domain to work in!
        
       | amluto wrote:
       | > However, because it is physically not possible to charge and
       | discharge the battery at the same time, such trades have to be
       | prevented.
       | 
       | The authors are observing that, if electricity prices are
       | negative and your battery is not perfectly efficient, then you
       | would like to charge and discharge simultaneously to get paid for
       | wasting energy, but you can't.
       | 
       | This is a silly limitation. Surely the power electronics or even
       | just the control algorithms in a BESS could be slightly modified
       | to consume power, get warm, and not transfer any current to or
       | from the battery cells, effectively taking advantage of the
       | BESS's heat sink to sink excess power and sell that service.
       | 
       | More seriously, in a world with occasional negative prices, you
       | would want your battery to be able discharge itself, without
       | exporting power, in a controlled and power-limited manner so as
       | to avoid overheating. And the optimization algorithms should
       | factor this in. I wonder if real grid-scale BESS systems have
       | this capability.
        
         | looofooo0 wrote:
         | Good luck trying to get rid of such an amount of heat anyway
         | near your batteries.
        
           | doener wrote:
           | Well in times of negative energy prices wouldn't it even be
           | good if the air conditioning ran at full capacity?
        
             | Energiekomin wrote:
             | In summer? If its not getting to cold for you.
             | 
             | In winter yes also if its not getting to warm for you, but
             | also heating water is easy enough. But you don't need that
             | much hot water
             | 
             | Potentially also cooling down your fridge more and your
             | freezer. But that is not that much energy.
             | 
             | While that works, it would still be quite a waste. It would
             | be a lot better to save it and discarge it later
        
             | WJW wrote:
             | Depending on how powerful your air conditioner is, it would
             | rapidly start cooling down the building to a temperature
             | which is too low to still be comfortable. You could maybe
             | buffer this with more thermal mass, but then you are back
             | in the game of storing energy and might as well just get
             | extra batteries.
        
               | sib wrote:
               | Why not place the air conditioner next to a large
               | electric space heater?
        
               | amluto wrote:
               | Many heat pumps already have a mechanism for deliberately
               | wasting energy for defrosting the coils. I bet that the
               | same hardware with a different control algorithm could be
               | convinced to heat out the outdoors without much net
               | change in indoor temperature. (The solution involving the
               | smallest amount of extra hardware is to run the system in
               | reverse periodically. There are other solutions.)
               | 
               | Whether the negative energy price is enough to balance
               | wear on the system and potential noise is a different
               | question.
        
             | KeplerBoy wrote:
             | Yes, it's not much of an issue if you have free energy.
        
               | lazide wrote:
               | It only makes sense if you have 'more than free' energy
               | you need to get rid of, because not getting rid of it
               | causes problems. Similar to flaring natural gas, but for
               | actual electricity.
               | 
               | This is not a common occurrence or situation, or
               | shouldn't be anyway, or someone is screwing up pretty
               | badly somewhere.
        
               | AndrewDucker wrote:
               | With variable sources of electricity it can be cheaper to
               | have capacity at a level that you sometimes overproduce
               | than to have a capacity that produces at a lower level,
               | and so mostly needs a backup source of power.
        
               | infecto wrote:
               | It's actually quite common. You have base load generation
               | stations and your highly variable solar and wind. There
               | are often times when the power at a wholesale rate dips
               | below zero. It's too costly to turn off your base load
               | plants and maybe both solar and wind are generating above
               | normal.
        
               | lazide wrote:
               | Solar inverters can just not draw the solar current, and
               | wind can generally just change the pitch on their rotors
               | at the individual level. The only ones that generally can
               | not help 'over produce' are baseload power stations as
               | they have actual physical inertia in very large turbines
               | and can't respond as quickly to demand.
        
               | infecto wrote:
               | Right but keep in mind these events are generally short
               | lived and depending on the market there may be
               | reliability guarantees that keep these open or specific
               | federal funding rates.
               | 
               | But like I said before when rates go negative you will
               | typically see it in occurrences where you have abnormal
               | conditions (wind and solar generating at the same time)
               | or aggressive night winds. And it does not happen long
               | enough to need to curtail generation.
        
               | petertodd wrote:
               | Baseload power stations sometimes over-produce on longer
               | timescales than just a few seconds because they'd rather
               | not turn them off for maintenance/operational reasons.
               | E.g. imagine you have a big biomass boiler feeding a
               | steam turbine. Turning it off for an hour or two means
               | everything cools down, which is a thermal stress,
               | reducing lifetime compared to keeping it at constant
               | power.
               | 
               | But yes, certainly poorly managed solar/wind that doesn't
               | have good mechanisms to turn off in response to lack of
               | demand is mainly the issue. In the future, when control
               | systems are better, I'm sure negative pricing will be
               | much less common.
        
               | KeplerBoy wrote:
               | Electricity prices around here (Austria) are negative
               | around noon on most summer days. They pay you to waste
               | all that solar energy people are feeding into the grid.
        
               | bee_rider wrote:
               | Is it really screwing up? If solar panels are cheaper
               | than batteries, then you can over-provision the solar
               | panels and then you won't need to use the batteries as
               | much, so you can probably get away with smaller
               | installations.
               | 
               | My gut would expect it to approach $0 if full
               | communication were possible, based on the instinct that
               | most people would run their dishwashers if the energy
               | cost was $0.
        
               | lazide wrote:
               | Solar panels don't produce excess power that needs to be
               | dissipated - just don't invert the unneeded current, and
               | that's it.
               | 
               | 'Overproduction' in this sense is from something like a
               | spinning generator which starts to overspin, or an
               | inverter which oddly starts to overvolt the output for
               | some inexplicable reason.
        
               | KeplerBoy wrote:
               | That only works if the grid operator has control over the
               | inverters, which they often don't have.
               | 
               | We currently have the situation where operators of solar
               | farms of all sizes get a fixed amount of money for each
               | joule they feed into the grid. Of course those people
               | have zero interest in turning down their inverters when
               | the sun is shining and there's already a surplus in the
               | grid.
        
               | lazide wrote:
               | That isn't actually structurally true - the way inverters
               | work is they do high frequency analysis of the output
               | power, and then 'push' energy in at various parts of the
               | waveform. That's how DC->AC inversion works. We're taking
               | much higher frequency than the AC waveform for any non-
               | terrible-quality inverter.
               | 
               | While they _can_ be configured to overvolt the outputs or
               | drive frequency higher than they should if they have the
               | excess energy, that is certainly not a normal setup and
               | seems pathological, frankly. Which I guess goes to your
               | point regarding solar operators - if they have an
               | incentive to keep pushing power into the grid even if the
               | grid doesn't need it, they certainly can configure their
               | equipment to do that. But that is also a clearly screwed
               | up situation for the grid eh? And of all the generation
               | providers, they are the ones with the least excuse to
               | actually do that.
               | 
               | It's trickier with something with moving parts (like wind
               | generation), where there may be some element of physical
               | inertia or direct physical coupling to the output power.
               | But inverters are _not_ that.
               | 
               | And my understanding is that all modern wind turbines do
               | automatic blade feathering and a significant degree of
               | voltage/frequency regulation to avoid blowing things up
               | 'downstream'. So with any luck it would be a minutes at
               | most, type situation.
               | 
               | Still, 90% of the problem is likely with wind farms or
               | the baseload eh? Unless the solar operators are doing
               | this intentionally to screw their competition.
        
           | _trampeltier wrote:
           | Some years ago, I helped with battery load tests in a nuclear
           | power station. The constant test load was just a big (~500kW)
           | heater. We burned the battery energy for 5 hours. So it's
           | easy possible to do such things.
        
             | horsawlarway wrote:
             | Exactly this.
             | 
             | And the same thing for residential scale is literally just
             | a ceramic space heater running at ~1500w.
             | 
             | They're dirt cheap, usually have temp safety checks built
             | in, work on a residentially sized circuit, and are
             | available everywhere.
             | 
             | I needed a cheap and consistent load to do LFP battery
             | testing, and I could spend $5,000 for a real test unit, or
             | $21 for a ceramic heater that will do basically the same
             | thing.
             | 
             | If you've already got the monitoring for the
             | batteries/inverters, a heater is a GREAT load choice.
        
               | petertodd wrote:
               | HAAS CNC mills are famous for using electric stove
               | elements for the spindle brake resistor: https://www.redd
               | it.com/r/CNC/comments/1es1d01/someone_didnt_...
               | 
               | I'm not sure that this really is a completely off-the-
               | shelf stove element. But obviously, the technology is
               | basically identical to what you'd have on your stove.
        
               | _trampeltier wrote:
               | It is cery common for Frequency Inverter for AC Motors to
               | have a break resistor. It's expensive to push energy back
               | to the grid with from an inverter. So in most case just a
               | break resistor is used. Just if you break a lot and a
               | long time it is worth to buy an inverter who can do it.
               | If you have multiple axis in a machine, often they are
               | coupled with DC, so the break energy is used by another
               | drive.
        
               | petertodd wrote:
               | Yup. On a much bigger scale it's common for the power
               | supplies going to electric trains to do this too. They
               | like to use regenerative braking because it's efficient.
               | But the electricity grid can't always handle the extra
               | power, so in some designs they have a backup mechanism to
               | dissipate the power if needed; diesel-electrics usually
               | just have a big bank of air-cooled load resistors on the
               | roof.
               | 
               | A neat example of regenerative braking being important is
               | the London Underground: they've had a persistent problem
               | with high temperatures in the subway, of which a decent %
               | is actually heat from trains braking. By using
               | regenerative braking rather than putting that energy into
               | the tunnels as heat, they can transport that energy
               | outside the tunnels, keeping them cooler.
        
               | looofooo0 wrote:
               | so you're installing a resistive heater? what is the
               | economics of that?
        
             | looofooo0 wrote:
             | 500kw is nothing, that is 1/3000 of the nuclear power plant
             | electric output.
        
         | jordz wrote:
         | I work in the industry making hardware and software for large
         | scale commercial and grid scale storage.
         | 
         | There are several challenges with this, safety, thermal
         | runaway, and life cycle of the asset which has a limited amount
         | of cycles.
         | 
         | Also the architecture of the system for the AC inverters and
         | the DC side can come from very different places in the supply
         | chain and aren't as vertically integrated leaving you in a
         | position where you can't actually make this work without
         | compromising something in the supply chain. That being said we
         | are talking about a LOT of energy in these systems and to
         | dissipate that much heat you'd need a load bank.
        
         | raphaelj wrote:
         | Couldn't the battery just do, as an example, 1 minute long
         | charge then discharge cycles?
         | 
         | For example, if the electricity price is -28EUR/MWh (like today
         | in Germany), and your battery efficacy is 80%, you could get
         | paid 28EUR/MWh charging, then only pay back 22EUR discharging,
         | generating a 6EUR/MWh profit.
        
           | 7thaccount wrote:
           | The wholesale energy markets don't have sub 5-minute
           | granularity anywhere that I'm aware of. In the US, 1-hour is
           | standard in the day-ahead markets and 5-minutes is standard
           | for the spot markets.
           | 
           | There is also the problem that your battery would likely
           | degrade fast depending on the technology.
        
         | 4gotunameagain wrote:
         | The solution is actually what's called a "dummy load". Get paid
         | to waste energy and heat up the planet a tiny bit more, gotta
         | love it.
        
           | thebruce87m wrote:
           | Can't we power a big laser and point it at space or something
           | instead? Anyone got a dumber idea?
        
             | beAbU wrote:
             | There are so many things that are energy intensive and not
             | really economically viable: co2 capture, crypto mining,
             | "green" hydrogen, we could see a world soon where a large
             | scale BESS would have an on-site dummy load that does
             | something useful with that electricity
        
               | Analemma_ wrote:
               | The problem with all those things is that they are
               | ridiculously capital intensive to set up, and then they
               | sit idle 80% of the time Worse, the whole point of
               | negative electricity prices is that they're an
               | inefficiency in the market which ideally will eventually
               | be optimized away. Then what do you do with your billion-
               | dollar plant that can only run with negative prices that
               | no longer exist?
        
               | adgjlsfhk1 wrote:
               | You're assuming the way they get optimized away isn't by
               | these sorts of plants.
        
             | karmakurtisaani wrote:
             | I guess the problem with building a pure energy waster is
             | that it could only operate every now and then, and it's not
             | guaranteed to see negative prices in a few years from now.
             | So, might not be all that profitable.
        
             | BobaFloutist wrote:
             | Use the electricity to heat up a lump of iron to a very
             | high temperature, than use electromagnets to fling it into
             | space?
        
               | yetihehe wrote:
               | If you heat up iron to very high temperature (>770degC),
               | it's much harder to fling it using electromagnets.
        
               | BobaFloutist wrote:
               | Ah that's annoying. Fine, we use the electricity to
               | heat...uh...molten salt encased in stone, and to pull
               | back a very big heat-proof slingshot, and after a
               | threshold it lets go and launches it into space.
        
             | msgodel wrote:
             | Obviously the complaint is about the changing atmospheric
             | absorption properties as a side effect of the generation
             | side, not the heat from using the power.
             | 
             | Either way I think people are overthinking it though.
        
           | noitpmeder wrote:
           | Isn't this the basic description of what a gravity battery
           | should provide?
        
             | horsawlarway wrote:
             | No, because his situation is basically that the gravity
             | battery is already sitting at its max height.
             | 
             | He's just trying to burn energy because a negative rate
             | means he's getting paid to use it.
             | 
             | So sure - it's great to give that energy a functional use
             | first (ex - charge his batteries) but eventually he runs
             | out of functional ways to use the energy but could still be
             | making money by using it.
             | 
             | Enter the desire for a dummy load.
        
               | rtkwe wrote:
               | Pumped hydro could do that if they had a way to bypass
               | (either physically or electrically) their turbines on the
               | downhill portion of the loop. Just pump water up and back
               | down without extracting the energy. Then you have a dummy
               | load that isn't just a power sink and is already designed
               | to handle the relatively rapid switches on and off.
        
               | horsawlarway wrote:
               | Yeah, but dummy loads are cheap. Probably cheaper than
               | changing any designs in other places.
               | 
               | It's straight forward to add a giant resistive load that
               | just converts electricity back to heat.
               | 
               | I can get 10kw heaters for just a couple hundred bucks or
               | 1.5kw heaters for literally $20 usd. And that also
               | switches on/off easily.
               | 
               | For hydro... just boiling water with a heater is going to
               | be pretty much unbeatable if we're playing the "waste
               | energy" game. No need to approximate it slowly with your
               | pump motor and risk other infrastructure.
        
               | rtkwe wrote:
               | The idea was to have dual use so that they're not
               | obsoleted when we get around to installing sufficient
               | power storage for renewables and also a less heat
               | intensive way to do it too.
        
               | quickthrowman wrote:
               | Giant resistors cooled with fans are cheaper and easier
               | to maintain than pipes and pumps.
        
               | hollerith wrote:
               | That is what (diesel powered) locomotives do to get rid
               | of electrical power created by using the wheel motors for
               | braking.
               | 
               | New designs store the power in batteries, but most
               | locomotives used in the US still have a compartment
               | filled with fans and resistors instead.
        
               | rtkwe wrote:
               | Yes of course. My idea was a way for existing facilities
               | to also function in this capacity so you didn't wind up
               | with facilities reliant only on negative prices. I think
               | that's important because those prices are a bandaid on
               | the real problem that would be solved by sufficient power
               | storage.
               | 
               | You can build this at a small scale pretty cheaply but
               | the connection to sink meaningful amounts of power would
               | quickly become a significant part of the expense.
        
           | fer wrote:
           | >"dummy load"
           | 
           | You mean crypto miner.
        
             | michaelt wrote:
             | Surprisingly, not always.
             | 
             | If I buy a device for $100 that, given free electricity,
             | will mine $500 of cryptocurrency in its useful life - I can
             | easily lose money if I run it less than 20% of the time.
             | 
             | And I doubt electricity is negative priced >20% of the
             | time.
        
               | bee_rider wrote:
               | Yeah, there are a ton of plans in this thread for what to
               | do with excess energy. The problem is, that's the wrong
               | question. The goal is to answer the question "what should
               | we do with excess energy where we don't mind building the
               | capacity, but then only rarely running it."
               | 
               | Rather than coming up with some grand scheme, maybe it
               | would be good if our dishwashers and washing machines
               | could listen to the grid and activate when power cost was
               | negative. (We may need to coordinate a bit though, so we
               | don't all activate at once).
        
               | rtkwe wrote:
               | In some areas negative prices account for up to 25% of
               | hours so it's a decent number but still a rough number of
               | spins up and down and a lowish duty cycle. A solution
               | might be to build battery capacity along side these loads
               | to effectively buffer the negative cost power to be able
               | to run continuously. That would skyrocket the initial
               | capital investment though.
        
               | bee_rider wrote:
               | Yeah, batteries are just the sort of
               | expensive/straightforward solution.
               | 
               | If you think of it, a dryer is sort of a combination of a
               | flywheel and a heating element, so it _should_ be the
               | over-provisioner's best friend. IMO a real failure has
               | been not taking advantage of our appliances.
        
               | rtkwe wrote:
               | The issue there is connectivity and most residential
               | customers don't pay spot prices so you need to upgrade
               | their meters as well or build metering into the appliance
               | so they can get credit for the energy they burn off. Plus
               | you're looking at putting a lot of extra cycles on
               | equipment not built as well as it used to be so you're
               | burning the useful life of a hard to repair device and
               | probably not getting paid enough to cover that, plus they
               | more and more designed to burn as little energy as
               | possible.
               | 
               | I know there are some places where this happens though
               | but it's more along the lines of the devices delaying
               | their start until energy is cheap rather than being used
               | as loads to shed excess capacity afaik.
        
               | bee_rider wrote:
               | > I know there are some places where this happens though
               | but it's more along the lines of the devices delaying
               | their start until energy is cheap rather than being used
               | as loads to shed excess capacity afaik.
               | 
               | This is what I meant, sorry for the ambiguity. Load the
               | washer up and kick it off whenever energy is cheap. I
               | don't care when it happens other than, like, that it
               | happens once a day, so why not defer this to the power
               | company, right?
        
               | rtkwe wrote:
               | Like I said support isn't really there for a lot of
               | electric customers. I pay a single flat rate for
               | electricity so there's no point in time shifting
               | consumption.
               | 
               | Also there are downsides to having clothes just sit there
               | for hours potentially before you dry them. They can get
               | pretty dank from the moisture and for dryers some clothes
               | need to be removed immediately when the cycle finishes.
        
               | quickthrowman wrote:
               | https://en.m.wikipedia.org/wiki/Load_bank
        
               | wcoenen wrote:
               | I have an electricity contract with dynamic pricing that
               | changes every hour based on the day-ahead electricity
               | market for Belgium. I know what the prices for the next
               | day will be around 13h10. I charge the car whenever the
               | prices are lowest: around noon in the sunny months, at
               | night during winter, preferably weekends. I save around
               | 25% of my electricity bill like this. (More in summer,
               | less in winter.)
               | 
               | So it's already possible to incentivize people correctly
               | with price signals, at least in some regions of the
               | world. But people are not yet familiar with this. I guess
               | that will change as the pricing between dynamic and
               | traditional contracts keeps diverging. With a traditional
               | contract, you are essentially paying the average evening
               | peak price all the time. With a dynamic contract, you get
               | access to the cheaper and even negative rates.
        
           | wcoenen wrote:
           | Presumably the negatively priced energy came from solar
           | panels, so those sun rays were going to heat the planet
           | anyway. The same still happens with a dummy load, just with
           | extra steps in between to convert to and from electricity.
           | 
           | With enough solar panels deployed, you could still argue that
           | they change the albedo of the Earth and therefore it's
           | temperature.
        
             | 4gotunameagain wrote:
             | Not necessarily. There's also reflection involved.
             | 
             | Now to figure out how much exactly you need to take into
             | account the solar panel absorption spectrum & the albedo of
             | the earth.
        
             | eisa01 wrote:
             | Related, do Solar PV panels need any extra equipment to
             | curtail instead of feeding into the grid?
             | 
             | Aside from software integration to remotely control
             | household PV systems, is there anything else needed to
             | curtail during negative price events?
        
               | nick3443 wrote:
               | If the inverter is smart enough, nothing else would be
               | necessary
        
               | eisa01 wrote:
               | Thanks! Google managed to find more details on Reddit
               | when I searched now
               | 
               | https://www.reddit.com/r/energy/comments/1iu2kkz/solar_cu
               | rta...
        
           | triceratops wrote:
           | Could we use it for some kind of carbon capture process?
        
             | Leherenn wrote:
             | I think it's pretty clear with the constantly increasing
             | durations of negative prices, so far we haven't found a way
             | to do so profitably. Carbon capture or anything else for
             | that matter.
             | 
             | Anything that would really love free energy also cost a lot
             | to build and maintain/operate besides electricity. So much
             | that a few hundred hours of free (or even better than free)
             | energy a year is far from enough when you need >90% uptime
             | to make sense. Maybe it makes you go from 95 to 85%, but
             | still clearly it's far more than there are sunshine hours.
        
             | grues-dinner wrote:
             | It's basically the idea behind things like hydrogen
             | electroysis with excess energy.
             | 
             | The problem is that things that can use bulk energy
             | productively like electrolysers, hydrocarbon crackers,
             | smelters, AI training farms, etc. are very expensive and
             | having them on warm standby but idle most of the time
             | waiting for good grid weather makes for bad returns on the
             | capital expenditure and operational costs.
        
           | Workaccount2 wrote:
           | I know this is grossly pedantic, but not matter what that
           | electricity is used for, it will end up "heating up the
           | planet a bit more". Energy is a waterfall whose base is heat.
        
             | pomerange wrote:
             | _Technically_ if you power a laser shooting into space with
             | solar panels you are cooling the planet, but you are
             | ofcourse right in practice and on the scale of the
             | universe!
        
               | stavros wrote:
               | That sounds like a good way to waste tons of energy
               | during negative electricity prices to me! Shoot it into
               | space.
        
             | _Algernon_ wrote:
             | Fossil fuels contain energy that are not in the form of
             | heat, so electricity from fossil fuels would heat the
             | planet even ignoring greenhouse effect. If from renewables,
             | however, the energy has been previously extracted from the
             | environment, thus being neutral in terms of heating the
             | planet.
             | 
             | Not that it matters, because the effect would be miniscule
             | in any case.
        
               | TGower wrote:
               | I did some napkin math and the amount of energy used from
               | burning buried coal and oil since the industrial
               | revolution began would warm the atmosphere about 3
               | degrees C. The assumption that all of the energy would be
               | dumped into the atmosphere and stay there is obviously
               | deeply flawed, but the overall effect might not be
               | miniscule.
        
         | ZeroGravitas wrote:
         | Not sure if it's discussed in the paper but apparently in
         | Australia there have already been recorded instances of
         | batteries charging with negative price electricity and then
         | selling back that electricity at a still negative but closer to
         | zero price and so profiting.
         | 
         | When I first heard it, it seemed wild that they couldn't hold
         | on for the price to go back above zero, but I guess if we're
         | talking high frequency trading it makes more sense. They might
         | have bought and sold many times while the price is different
         | levels of negative before switching to charging up in
         | preparation for the later price rises.
         | 
         | And the round trip inefficiency helps too.
        
           | petertodd wrote:
           | That's not as ridiculous as it sounds!
           | 
           | As you know, negative electricity prices mean that someone is
           | willing to pay you to dispose of electricity they need to
           | generate for some reason. For example, a conventional steam-
           | turbine-based electricity plant might prefer to just keep
           | running for a brief period of time when demand is low, rather
           | than subject their equipment to a power cycle, which
           | increases their maintenance costs. There's other, dumber,
           | examples based on stupid contracts and badly designed
           | solar... but this example is a reasonable one that exists for
           | good engineering reasons.
           | 
           | The battery provider in this circumstance is profiting from
           | their ability to accept power when demand to dispose of
           | electricity is particularly high. When that need goes down,
           | they can reasonably profit by dumping that energy on someone
           | else who is _also_ able to dispose of the electricity. But at
           | a lower cost. E.g. imagine an big industrial refrigerated
           | storage facility that can consume _some_ excess energy by
           | supercooling their refrigerators. But they can 't consume
           | unlimited excess energy, because at some point their
           | warehouse just gets too cold, and they don't have unlimited
           | refrigeration capacity anyway.
           | 
           | So in this simplified example, the battery storage service is
           | getting paid a lot of money to quickly absorb a lot of
           | energy, which they then dump more slowly to the refrigerated
           | warehouse (and similar providers) as the surplus diminishes,
           | in anticipation of another surplus in the near future.
        
             | kurthr wrote:
             | If it was so profitable, why wouldn't the electricity
             | utility do it themselves? Certainly, they have the scale,
             | infrastructure, and pricing power to do it.
             | 
             | Oh, that's right. This is supposed to be wealth transfer.
        
               | schmidtleonard wrote:
               | Someone at the generation facility ran the numbers and
               | found that the grid was able to dispose of excess energy
               | for peanuts but installing and maintaining a dedicated
               | electronic load cost more than peanuts.
               | 
               | I'd recommend digging elsewhere for conspiracy bait. This
               | is a mild curiosity at best.
        
               | hinkley wrote:
               | This is why we don't move data center load to the coldest
               | available data center to reduce the AC power fraction of
               | the cost. The cost of electricity is a significant
               | fraction of the overall cost but not high enough to make
               | up for stranded assets. Computers not running during
               | their best years is expensive.
               | 
               | But I'm not sure that's entirely correct, and maybe it's
               | time to revisit this.
               | 
               | Any system that is selling responsiveness as part of
               | their service has to keep a certain amount of equipment
               | sitting idle. That's just how queuing theory works. So
               | while you cannot move all server load to the coldest
               | available zone, we should still be able to run that
               | center near capacity and use the hottest one for all
               | reserve capacity.
               | 
               | Power plants also have to deal with fines for exceeding
               | emissions limits, but I suspect the problem here is that
               | Bayesian analysis tells them that if a plant has to kick
               | on early for some reason (early school release day, or
               | another plant exceeded a maintenance window), it will
               | still be needed for sure an hour from now, so it's better
               | to leave it running for 45 minutes doing nothing than to
               | cycle it.
        
               | petertodd wrote:
               | > This is a mild curiosity at best.
               | 
               | Exactly. There are genuine economic/engineering reasons
               | for negative prices to occasionally exist. But in a well-
               | designed, well-run, grid price will be negative only a
               | small minority of the time. It just doesn't make sense to
               | install a bunch of expensive equipment to provide this
               | service when sufficient capacity exists from "happy
               | accidents" like spare battery storage.
               | 
               | In the long run, better managed solar and wind should
               | make negative prices a fairly rare event.
        
               | eru wrote:
               | Once you sign up customers for 'cheaper electricity, but
               | you have to agree to the occasional loadshedding', you
               | can probably also sign them up for a bit of 'oh, and
               | please burn some more electricity, when we tell you to'.
               | 
               | The former is already happening and useful, the latter
               | would be a relatively simple and easy add-on that could
               | be used to offer ever so slightly cheaper electricity.
        
               | jounker wrote:
               | My washing machine has a timer. I do the wash when local
               | electricity rates are near zero.
        
               | eru wrote:
               | Yes, and you could imagine telling your utility: just
               | kick off the laundry anytime in this time interval, in
               | return for cheaper electricity.
        
               | bee_rider wrote:
               | I'm just guessing but it probably isn't _so_ profitable.
               | More like a "you already have the batteries, so why not?"
               | type thing.
        
               | pfdietz wrote:
               | One reason, that I understand has applied in Germany, is
               | when taxes are applied both to the electricity the
               | storage firm buys and to that which it sells. This puts a
               | damper on the whole thing unrelated to any actual
               | technical or economic realities.
        
               | 0cf8612b2e1e wrote:
               | Even if the arbitrage exists, it does not mean you are
               | equipped to profit from it. Furthermore, the rapid
               | installation of battery capacity means that the profit
               | margin for this activity is likely to dwindle as more
               | entrants try and do the same thing.
        
               | jandrese wrote:
               | Your electric utility could be doing this if they were
               | more forward thinking and installed grid scale batteries,
               | but that's not their business model so they don't do it.
        
               | eru wrote:
               | Well, if other people are allowed to install batteries,
               | then it might be fine that the utility isn't doing that.
               | They don't need to do everything themselves.
        
               | rcxdude wrote:
               | What do you mean by electricity utility? Which
               | organisation specifically? The electrical supply is
               | usually formed of multiple organisations with different
               | responsibilities, which usually works pretty well, but it
               | generally means that e.g. storage, transmission, and
               | generation are not one single organisation.
        
               | nwbort wrote:
               | Yes, including because firms at one level of the supply
               | chain (eg, transmission) are in many countries precluded
               | from operating in another level (eg, generation).
        
               | adrianN wrote:
               | If you find a hundred dollars on the ground you don't
               | pick it up because in an efficient market somebody else
               | would have already picked it up, hence it can't be real?
        
             | eru wrote:
             | > That's not as ridiculous as it sounds!
             | 
             | I'm not sure: why doesn't someone 'just' put up a few
             | resistive heaters and fans to benefit from negative prices?
        
               | Turskarama wrote:
               | Because it doesn't happen often enough to be worthwhile,
               | you're better off just building a battery and being able
               | to make profit every day.
        
               | ssl-3 wrote:
               | If one is incentivized (eg, paid) to burn power, then
               | sure: One can burn power and reap the incentive. It can
               | happen in any market. The producer has so much abundance
               | of a thing, for whatever reason they do, that they're
               | willing to pay others to get rid of it for them.
               | 
               | It can even happen productively: "Hey, they're paying us
               | to run the heat! Turn the glass kiln on so we can get a
               | head start on tomorrow."
               | 
               | Or "Hey, they're paying us to charge our batteries! Let's
               | charge them!"
               | 
               | It can also be "Hey, they're paying us to run resistive
               | heaters! Turn on the artificial sun!"
               | 
               | Whatever it is: If the demand satisfies the supply, then
               | the supplier is satiated. And then the price can go back
               | to something more-profitable for that supplier.
        
               | gus_massa wrote:
               | > _It can also be "Hey, they're paying us to run
               | resistive heaters! Turn on the artificial sun!"_
               | 
               | It may be difficult to dump all the heat at scale. You
               | probably need a huge cooler with fans to get active air
               | flow. Or a water tower (that requires water) (There are
               | regulation about extracting water from a river and
               | returning it too hot).
               | 
               | Is it possible to build one of this heat dumping
               | facilities in a zone where there is permanent snow?
               | (Ignoring environmental and moral concerns.)
               | 
               | PS: Seriously, heating a swimming pool may be a nice
               | application.
        
               | eru wrote:
               | > It may be difficult to dump all the heat at scale. You
               | probably need a huge cooler with fans to get active air
               | flow. Or a water tower (that requires water) (There are
               | regulation about extracting water from a river and
               | returning it too hot).
               | 
               | You could probably just boil off your water, instead of
               | returning any?
               | 
               | It would be funny, to use the steam to generate
               | electricity.
        
               | ssl-3 wrote:
               | It definitely is sometimes difficult to dump power at
               | scale. That's the source of the surplus and resulting
               | negative price.
               | 
               | But it doesn't have to be big. A negative price is still
               | a negative price, even on a small scale.
               | 
               | So, for instance: At home, I have electric hot water. I
               | have some baseboard heaters in parts of the house (that I
               | never actually use, but which I could use). I have
               | central aircon.
               | 
               | All of these things could stand to be automated just for
               | automation's sake, and that's something I'll probably do
               | some day even with the fixed-rate electricity I buy right
               | now.
               | 
               | With automation and price feeds, it's a programmatic no-
               | brainer to switch on the electric baseboards on during
               | the heating season during negative price events and get
               | paid some non-zero amount to get ahead on the temperature
               | game.
               | 
               | During the cooling season, I can probably stand to get
               | paid to supercool the house for awhile.
               | 
               | And during any season: I normally run my electric water
               | heater at a fairly low temperature because that's more
               | efficient, but I'll cheerfully accept money to
               | temporarily raise its temperature.
               | 
               | Or if I had an EV: Maybe I might normally like to keep it
               | at 70% SoC for battery health, but if it's plugged in and
               | the price is negative then I might cheerfully run it up
               | to 85 or 90% or more.
               | 
               | So anyway, it's hypothetically pretty easy for an
               | individual like me to dump a few kiloWatts in a useful
               | way.
               | 
               | A thousand such people make it easy to dump a few
               | megaWatts.
               | 
               | A million such people make it easy to dump a few
               | gigaWatts. (And a million sounds like a lot, until one
               | counts the eventuality of smartly-connected EVs.)
        
               | HPsquared wrote:
               | Freight trains have very powerful versions of those
               | onboard. You'd just have to repurpose them. It's called
               | "dynamic braking".
               | 
               | https://en.m.wikipedia.org/wiki/Dynamic_braking
        
               | eru wrote:
               | Some electric cars have that as well.
               | 
               | Btw, many passenger trains have something like that as
               | well, especially in the metro or tube: the stations are
               | deliberately built slightly higher than the normal lines,
               | so that you can convert kinetic and potential energy back
               | and forth.
        
               | jakewins wrote:
               | People do - but the actual answer to your question is as
               | you're implying: it's not as simple as "you get paid to
               | consume".
               | 
               | There are negative spot prices in Europe all the time -
               | but they are not usually negative enough to make up for
               | the grid fees and taxes. Or they are in countries like
               | Germany that hasn't rolled out smart meters, so consumers
               | have no way to access spot prices
        
             | K0balt wrote:
             | Oxygen capture and liquid nitrogen seems like a great use
             | of negative prices.
        
           | foobarian wrote:
           | > and then selling back that electricity at a still negative
           | but closer to zero price and so profiting.
           | 
           | How is it not better to discharge the batteries instead? I
           | guess if you don't have that hardware option integrated into
           | the platform maybe, but otherwise...
        
         | _trampeltier wrote:
         | I know a country, the national train company turns lots of
         | outside lights on (daytime), if the price is negative.
        
           | _Algernon_ wrote:
           | Great for the local insect population.
        
           | cyri wrote:
           | Yes that is the SBB in Switzerland but they do not turn the
           | lights, instead they turn on the heaters for the track
           | switches. Not sure if that is all rumours.
        
         | hwillis wrote:
         | > Surely the power electronics or even just the control
         | algorithms in a BESS could be slightly modified to consume
         | power, get warm, and not transfer any current to or from the
         | battery cells, effectively taking advantage of the BESS's heat
         | sink to sink excess power and sell that service.
         | 
         | Unless you specifically design for it (specifically, with a
         | dummy load), the efficiency of the system is inversely
         | proportional to its ability to do this. You need a secondary
         | system.
         | 
         | The power system can connect the battery terminal to in or to
         | out, so if you switch both on at once you effectively bypass
         | the battery. It's called shoot-through current and is generally
         | considered a destructive process. If you can switch on and off
         | fast enough you could limit it to a non-destructive level, but
         | in practice most systems will not switch fast enough. They are
         | designed to operate with the battery load, which is at minimum
         | ~10x higher resistance than the transistor itself. In practice
         | it is often 100s of times higher.
         | 
         | That's where the efficiency comes into it. If a power system is
         | 98% efficient (pretty normal- this does not include power lost
         | to heat in the battery itself), that means the electronics can
         | only burn 1/50th as much power as normally passes through the
         | system. Worse, when you put the switch into shorted position it
         | will try to pass 50x its rated current. You need to switch much
         | faster - _certainly_ more than 50x faster- and that will
         | probably put it outside its operating region.
         | 
         | It is relatively easy to just have a large resistor, but it is
         | not very well suited to use battery power systems. Batteries
         | are very low impedance, and the power system exists to
         | transform to a lower voltage and higher current. Resistors are
         | cheaper when they are higher voltage, so the power system is a
         | hacky kludge.
         | 
         | The overall solution is just more batteries. Oversupply is a
         | transient problem and always will be.
        
           | ACCount36 wrote:
           | > Unless you specifically design for it (specifically, with a
           | dummy load), the efficiency of the system is inversely
           | proportional to its ability to do this. You need a secondary
           | system.
           | 
           | Many multicell BMS already have this kind of "power shedding"
           | capability. They use it for cell balancing - to equalize
           | voltage between cells with slightly different
           | characteristics. This is desirable despite the power waste,
           | because it reduces wear, increases charging efficiency and
           | allows battery packs to last longer.
           | 
           | Some battery packs are also designed to be able to dump
           | enough power into heat to be able to keep the batteries warm
           | during extreme cold.
        
             | ranma42 wrote:
             | The amount of power you can dump for balancing is just a
             | fraction of the charge/discharge power (because it only
             | needs to offset differences in self-discharge rate). So you
             | still need a proper dummy load when you want to dump more.
             | 
             | Similarly, the heatsinking capacity of the battery is
             | designed for charging/discharging losses (say 5% of
             | charge/discharge power).
        
         | andoma wrote:
         | Our house have geothermal heating (heatpump conncted to 160m
         | drilled hole, pretty common in Scandinavia). The heatpump
         | supports having a coolant loop for cooling the house in the
         | summer. Thus the heat pump pretty much exchanges heat from the
         | house to the well (heating it up ever so slightly). It would
         | certainly be possible to insert a resistive dummy load on that
         | loop and just store that heat in the bedrock as well.
        
           | frabert wrote:
           | This! Or, if you don't have geothermal heating but have an
           | electric water heater, maybe temporarily increase the
           | temperature it goes to: maybe it's normally set to go to 65C,
           | then when you detect that you have negative prices and your
           | batteries are full and your water already hot, maybe heat the
           | water to 70C and store that little bit of extra energy as
           | heat! If you have thermostatic valves in your bathrooms, you
           | won't even notice the difference except by the fact that your
           | water heater now can apparently hold a little bit more water
           | than usual :)
        
             | cogman10 wrote:
             | Assuming regular negatives (more than once a day) you could
             | also tie the heating to the grid prices with maybe an hour
             | buffer around your high water usage times to make sure you
             | are up to temp.
             | 
             | Modern water heaters will keep temp for a shockingly long
             | period of time.
        
             | holri wrote:
             | I have a heat pump for hot water and calculated this with
             | an offered floating energy tariff. It is not economical
             | because the high net tariffs are not floating but fixed per
             | kwH and negative / very low prices are seldom here and only
             | for a short period of time available.
        
         | triceratops wrote:
         | If you have free energy the obvious thing to use it for is
         | carbon capture.
        
           | bee_rider wrote:
           | I wonder if desalination would be another good use. But,
           | yeah, it is probably just a matter of how fast the processes
           | can absorb extra power.
        
             | cogman10 wrote:
             | District heating and cooling would be an excellent sink for
             | the power.
             | 
             | Water needs a lot of energy to cool or heat, concentrated
             | at a district, you could easily absorb a lot of energy at
             | negative prices.
        
               | XorNot wrote:
               | Electric heating elements aren't free nor infinite in
               | capacity. You'd pay a lot of money for a rarely used
               | asset that has to be replaced by something else most of
               | the time because people want their heating to be
               | reliable.
        
               | nasmorn wrote:
               | But it is not horrible. A lot of people have resistive
               | water heating for their solar setup because grid sell
               | prices are super low and a 2kw water heater cost
               | basically nothing.
        
               | cogman10 wrote:
               | > Electric heating elements aren't free nor infinite in
               | capacity.
               | 
               | They are about as close to an ideal load as one could
               | imagine.
               | 
               | And capacity is easily expanded with a water tower. You
               | can scale the total thermal energy stored and the
               | efficiency of that storage by simply building a very
               | large water tower. You don't even need special insulation
               | because the water insulates itself.
               | 
               | > You'd pay a lot of money for a rarely used asset
               | 
               | Assuming you've converted over to district heating and
               | cooling, it'd be frequently used as climate control for
               | surrounding buildings.
               | 
               | > that has to be replaced by something else most of the
               | time
               | 
               | What? No. District heating is the most efficient way to
               | provide climate control, bar none. The only thing that
               | needs to happen is setting minimum and maximum temps.
               | Maintain the minimum temp and when negative power price
               | events hit heat to the maximum or cool to the minimum.
               | 
               | And if you want to get super clever, part of your storage
               | can be sand which can store huge amounts of energy.
               | 
               | > because people want their heating to be reliable.
               | 
               | District heating/cooling is as reliable as plumbing.
               | That's because that's effectively all that it is. It's
               | super reliable. If the incoming water is 60C or 90C, it
               | doesn't make too much of a difference in terms of heating
               | a home.
               | 
               | It's a proven tech. Many universities use it because it
               | significantly reduces the heating and cooling cost for
               | their buildings. My own city uses district heating in the
               | downtown to great effect.
        
             | positr0n wrote:
             | The problem is desalination plants cost billions. You're
             | not going to make money building one then running it the 1%
             | of the time the price of electricity is negative.
        
           | rtkwe wrote:
           | The big problem there is you have these intensely capital
           | expensive capture plants sitting idle around 75% of the time.
           | Also the processes may not gracefully start and stop though
           | maybe you could smooth that out by building a huge battery
           | bank along with the CC plant to effectively run a full duty
           | cycle with 'free' energy. That bumps the capital costs up
           | again though so the economics get tricky.
        
             | rcxdude wrote:
             | Yeah. Anything that's designed to use nearly-free or
             | negative-priced energy from the grid needs to be cheap to
             | build and easy to start and stop (The former being one of
             | the main issues with the 'bitcoin mining as grid
             | management' idea).
        
               | rtkwe wrote:
               | In theory if you run it using negative priced energy you
               | could maybe run with older less efficient hardware that's
               | not viable for current mining that would be much cheaper,
               | if you can source it. I'm thinking older ASICs for BTC
               | for example where the best in class kHash/W has moved on
               | and the price doesn't support running the older devices
               | but the negative price would offset that by giving a
               | reliable return on time to offset the extra energy
               | burned.
               | 
               | It'd take a far amount of math to figure out if that tips
               | it over though I don't feel like tackling haha.
        
           | ZeroGravitas wrote:
           | The real low hanging fruit is energy use you were going to do
           | earlier/later anyway but where timing isn't important.
           | 
           | Heating water, cooling water, pumping water, charging
           | batteries, running power hungry machines.
           | 
           | It's half century old tech and usually the only thing missing
           | is a financial incentive to do so.
        
         | matthewdgreen wrote:
         | Wouldn't that discharge the battery and hence contribute to
         | battery wear, by wasting a charge cycle?
        
         | borner791 wrote:
         | Balancing.. thats probably 1-0.5% of the BESS capacity. The
         | impedance of LFE cells are so high when charged pretty small
         | amounts of energy can slosh around before a protection
         | disconnect, over voltage for example
        
         | adiabatichottub wrote:
         | I don't know why it rankles me to think that generated power
         | should be fed into a dump load just to make the storage owners
         | extra money. Even though it's inefficient at the system level,
         | it shouldn't be harmful releasing energy that would have been
         | eventually dissipated as heat anyways. And yet it still just
         | feel wasteful to me.
         | 
         | I had to go search my bookshelf for this one:
         | "There has been an increasing awareness among engineers of the
         | last two decades that machines can perform a useful purpose in
         | many applications, even though their characteristics do not
         | conform to the orthodox standards of goodness.  The main
         | objective of the engineer is to make money -- to exploit
         | economically the physical properties of materials.  Economic
         | considerations, however, do not stop at the first cost of an
         | article, nor at the running cost, but extend to everything
         | connected with that article in the situation in which it is to
         | be used."
         | 
         | Eric R. Laithwaite, _Induction Machines for special purposes_
        
           | colechristensen wrote:
           | >I don't know why it rankles me to think that generated power
           | should be fed into a dump load just to make the storage
           | owners extra money. Even though it's inefficient at the
           | system level, it shouldn't be harmful releasing energy that
           | would have been eventually dissipated as heat anyways. And
           | yet it still just feel wasteful to me.
           | 
           | This is one of those efficient market things where you need
           | to manage the market in order that wasteful things happen
           | sometimes... but that waste is an opportunity.
           | 
           | If you and your competitor are both in the business of
           | dumping energy into heat, you're going to compete with each
           | other for access to that money.
           | 
           | Then one of you is going to try to find a way to make _more_
           | money with that energy and find something quickly scalable
           | with not-too-high idle overhead costs to do with that energy
           | besides just flowing through a resistor.
           | 
           | Negative prices are a sign of an inefficient market or just
           | the lag time between a changing landscape of resources and
           | someone to utilize them.
           | 
           | If there's a free resource someone's going to figure out how
           | to use it, just let it hang out for a while and the problem
           | fixes itself.
           | 
           | Especially with solar energy, this is just going to be a
           | thing. There's a certain balance where overprovisioning is
           | cheaper than storage and so you just do that. Then you wait
           | for industry (or consumers) to figure out how to take
           | advantage of the intermittent cheap energy.
        
             | eru wrote:
             | > Then one of you is going to try to find a way to make
             | _more_ money with that energy and find something quickly
             | scalable with not-too-high idle overhead costs to do with
             | that energy besides just flowing through a resistor.
             | 
             | Yes, exactly.
             | 
             | Which reminds me of the occasional story about how one
             | native group or another was so in tune with nature, because
             | they used every part of the (insert important animal here).
             | 
             | Modern economies obviously use all parts of the animal, for
             | exactly the reason you outline.
             | 
             | > Especially with solar energy, this is just going to be a
             | thing. There's a certain balance where overprovisioning is
             | cheaper than storage and so you just do that. Then you wait
             | for industry (or consumers) to figure out how to take
             | advantage of the intermittent cheap energy.
             | 
             | Yes, though you also need to make sure that regulations
             | don't get in the way. Or at least not too badly.
             | 
             | One example I can think of is forcing utilities to charge
             | people by net-metering, forcing the utility to implicitly
             | pay the same price for electricity as they charge. We don't
             | do that for eg used car salesmen.
        
               | colechristensen wrote:
               | >One example I can think of is forcing utilities to
               | charge people by net-metering, forcing the utility to
               | implicitly pay the same price for electricity as they
               | charge. We don't do that for eg used car salesmen.
               | 
               | A large proportion of the cost of consumer electricity is
               | distribution built in to the per kWh cost. Their buy
               | price needs to be lower than their sell price. I think
               | most people would be surprised by how much of the cost of
               | their electricity is incurred between the power plant and
               | their home.
        
           | nhecker wrote:
           | My shallow understanding is that utilities and grid operators
           | need to manage the supply/load ratio carefully to keep the
           | grid's operating frequency in a very narrow band, centered
           | around 50 or 60 Hertz. If supply outstrips demand, and
           | assuming supply can't react [quickly enough], the operating
           | frequency starts to rise as all the rotating masses connected
           | to the grid gain momentum from the additional power. If the
           | operating frequency increases too much outside of design
           | parameters that could end badly.
           | 
           | So one solution is to incite demand (with negative rates) for
           | folks to ramp up their use of electricity (into e.g., a dump
           | load resistor bank), bringing demand back in line with
           | supply, and bringing the operating frequency back under
           | control.
           | 
           | I hate the waste, agreed. But it would be irresponsible of
           | the operator to bank that extra supply energy into the
           | momentum of spinning things owned by the consumers just so
           | they could pull it out later by intentionally under-
           | supplying. E.g., an aquarium's big water pumps designed to
           | spin only so fast or produce so much pressure might not like
           | being operated at 110% the rated speed at random times of the
           | day.
           | 
           | related links:
           | 
           | https://fnetpublic.utk.edu/frequencygauge.html (you can watch
           | the grid frequency fluctuate in real-time, here!)
           | 
           | https://en.wikipedia.org/wiki/Stuxnet
           | 
           | https://en.wikipedia.org/wiki/Utility_frequency
        
             | MostlyStable wrote:
             | The grid connected thermostats, where the energy provider
             | has (some amount of) control over when you heat/cool your
             | house are pretty unpopular (I know people who have had
             | their AC turned off during heat waves and were not very
             | pleased). But this seems like an application of that that
             | people would like? And most people would probably even be
             | happy with just dramatically reduced/free heating/cooling
             | and not actually needing to get paid. And of course it has
             | the added benefit of actually using the energy in a useful
             | manner, rather than just wasting it.
        
               | eru wrote:
               | I suspect you can make these things work, but it's not
               | 'free': organising a bunch of retail customers and
               | dealing with them takes a lot of effort.
               | 
               | > (I know people who have had their AC turned off during
               | heat waves and were not very pleased)
               | 
               | I suspect they probably agreed to pretty harsh control in
               | the name of cheaper electricity, but actually were only
               | willing to tolerate relatively small amounts of
               | loadshedding. I wonder whether better contracts can help
               | align expectations here in the future. Eg allow the
               | electricity company to set your aircon's thermostat up to
               | 3K warmer (or something like that), but not turn it off
               | completely?
        
         | fluorinerocket wrote:
         | Find area near shore, stick two big electrodes in water a mile
         | apart, energize circuit when price is negative, profit!
        
           | idiotsecant wrote:
           | I am in the power generation industry and I have honestly
           | wondered why nobody does this. I figure getting the
           | interconnect big enough to make meaningful money is both
           | prohibitively expensive and a lengthy delay.
        
             | CoastalCoder wrote:
             | Or put them closer together and generate all of the
             | chlorine gas, H2, and O2 a girl could want!
        
         | thescriptkiddie wrote:
         | there are no circumstances under which it makes sense for
         | energy prices to actually be negative. it is a sign of a market
         | behaving very badly. propping up prices by intentionally
         | wasting energy only treats the symptom not the cause.
        
           | AnotherGoodName wrote:
           | It's only ever brief and essentially a penalty to power
           | generators for not turning off the generation in a reasonable
           | time
        
             | londons_explore wrote:
             | In most markets, it happens because one player is being
             | given some subsidy - ie. 'we will guarantee all power you
             | sell sells for $X/MWh', or 'You get a contractual green
             | bonus of $$$ if you produce XMWh this year'.
             | 
             | Those contracts mean the person producing the power is
             | still incentivised to do it even with negative prices.
        
         | burnt-resistor wrote:
         | Supercapacitors ready to soak up power to charge batteries
         | whenever rates stabilize.
        
           | XorNot wrote:
           | Supercapacitors are much more expensive then batteries with
           | much shorter lifespans to boot (years, versus decades).
        
         | msgodel wrote:
         | I think they just don't understand how such a market would
         | work. You'd trade futures on the power and if you hold the
         | contracts to maturity you'd be on the hook for
         | delivering/accepting the power. Everything before maturity
         | happens on paper.
        
       | elzbardico wrote:
       | Jesus! Why finance people are so hell-bent in extracting rent
       | from every single thing, pervert it, make sure the incentives are
       | all pointed to the shortest run while socializing all the costs
       | to the rest of us?
        
         | lazide wrote:
         | Smart People with money are willing to give it to people if
         | they can make them more money.
         | 
         | Why would anyone give them money if they were just going to
         | throw up their hands and go 'well, nothing we can do I guess!'.
         | 
         | There is of course the risk that the money gets burned instead
         | of more money getting made, which is the risk in risk/reward.
         | 
         | Rent seeking type behavior tends to happen when there are no
         | obvious 'green field' type endeavors to invest in. Or when risk
         | appetites are trending negative.
         | 
         | Note - many of those people with money that want to use it to
         | make more money are retirees, pension funds, etc.
        
         | ic_fly2 wrote:
         | More money made with batteries means more batteries installed.
         | How is that a bad thing?
        
           | cess11 wrote:
           | Profit motive commonly has obscene consequences, like
           | destroying food instead of using it to feed the hungry.
        
             | yxhuvud wrote:
             | While true that it happens in certain cases, the onus of
             | showing that it would be the case in this specific case is
             | still on you.
        
               | cess11 wrote:
               | I basically just did, that's how markets of this kind
               | work. If it is more profitable to warm the wind along a
               | mountain side than some cold person, then that person
               | will stay cold.
               | 
               | Poverty and misery in the world are mainly caused by this
               | kind of mechanism.
        
               | yxhuvud wrote:
               | If it is profitable to produce heat, it means prices are
               | negative. If prices are negative, then that is true also
               | for cold people.
               | 
               | On the other hand if prices are high, and someone has
               | sells electricity that was bought when prices were close
               | to zero, then the cold people will get warm for cheaper
               | than if there wasn't a battery.
               | 
               | Sorry, but you really make no sense.
        
               | cess11 wrote:
               | Manufactured scarcity and related phenomena are really,
               | really common. You should probably look into themes like
               | the tendency of the rate of profit to fall and planned
               | obsolescence and so on, and then explain why this
               | specific case of coked yuppie market would be immune to
               | them.
        
               | yxhuvud wrote:
               | Again, more players in the market (both batteries and the
               | renewables they enable) and the base fact that batteries
               | pull prices toward the mean means that if anything, they
               | would be exactly one of the mechanisms to avoid
               | manufactured scarcities.
        
               | cess11 wrote:
               | Why would this specific application of this type of
               | market be immune to rent seekers, manufactured scarcity,
               | wasting or withholding resources for profit, oligopolies
               | and so on?
               | 
               | What makes this application of this social regime so
               | different from e.g. food or medicine?
        
               | ajsnigrutin wrote:
               | In many countries, energy production was (and still is)
               | owned by the countries and power prices are regulated. In
               | cases of total system failures (eg. look at ukraine),
               | power usage is restricted by shutting down different
               | parts of the country at different times, so your area has
               | power from 4pm to 6pm, other area has it from 6pm to 8pm,
               | etc, industry gets partially shut down, partially works
               | at night if it's needed. Everybody gets to cook and wash
               | in their timeslots, and the rest of the time, they're
               | equally without power.
               | 
               | In case of some failure of the system you're proposing,
               | the prices would skyrocket, the poor would not get power
               | at all, and the rich would have power all the time but
               | for a very high price. Economically speaking, that's
               | great for investors in batteries and supporting systems,
               | socially speaking, it's a horible world to live in. And
               | the system is very unstable already, in portugal it
               | already failed horribly not long ago.
        
               | rcxdude wrote:
               | In this case there are two things that contribute: one is
               | cost of distribution, which means that it does in fact
               | cost something to get the electricity to the cold person,
               | and the second thing is the kind of structures which help
               | insulate consumers from extreme prices: most people pay a
               | fixed rate for electricity despite the variation in the
               | wholesale price, which means that while they may pay some
               | amount while the price is negative, they are also not
               | paying a small fortune when the price goes up massively.
               | This could probably be done better, though, and things
               | are changing which would do make electricity free or
               | negatively priced for some end-users when there's excess
               | in the grid, while still insulating them from extremely
               | high prices (they're still going to be paying something
               | for the insurance, though).
        
               | daedrdev wrote:
               | When the grid has to much money for 10 seconds, the cost
               | of finding an having a productive asset that is ready to
               | accept such a short burst of energy means that paying
               | people to throw it away can easily be cheaper, leaving
               | you with net positive money that can be used towards
               | keeping people warm. Real systems involve tradeoffs, and
               | so there will always be some short enough time frame
               | where throwing away energy is better for society and
               | human welfare than building infrastructure to use it.
               | Everyone already using the energy gets it for free when
               | prices are negative.
        
             | rcxdude wrote:
             | This tends to more to do with food supply security and
             | costs of distribution than anything else (as well as
             | political opposition to socialising food supply).
             | 
             | i.e. if we want to avoid food shortages, we need to
             | overproduce the raw goods and therefore waste some.
             | Transporting and transforming those raw goods into food
             | that someone can eat still costs money, it's not just so
             | farmers can get paid. We probably should still actually
             | make sure no-one goes hungry, but that does actually
             | involve some cost and effort on the part of the government,
             | and the challenge there is mainly political elements who
             | don't like the idea of someone getting something for free.
        
               | ajsnigrutin wrote:
               | Yep, that's why we pay farmers to keep half their fields
               | empty, because in case we need those fields (eg. war
               | somewhere), we still have farmers with all the machines
               | and infrastructure needed to produce food, that can
               | expand onto the now-empty fields.
        
           | aitchnyu wrote:
           | No need of speculators. A utility purchases cheap off peak
           | power and extremely costly peak power and pass the costs to
           | the consumer. If the utility pays homeowner with BESS
           | something comparable to peak power rate, they can recover
           | their investment quickly.
        
             | yxhuvud wrote:
             | Such an utility would be a speculator.
        
         | yxhuvud wrote:
         | If this was implemented in full scale, then it would ..
         | stabilize energy prices towards the mean, and make the energy
         | transmission more stable and resilent in general. I'd happily
         | pay some overhead for that, as it also mean the network can
         | accept more cheap energy sourced from wind and solar.
        
         | baq wrote:
         | Capitalism is the only form of communism that works on longer
         | time frames. Periodic resets are still needed, otherwise the
         | monopolist becomes the ruler.
        
         | driverdan wrote:
         | Except this is exactly what you want to happen. The reason
         | electricity prices range is because of supply and demand.
         | Batteries help smooth out the supply curve.
         | 
         | In the short term adding more batteries may allow someone to
         | generate income using this strategy but long term what it will
         | do is push electricity prices down and prevent power generation
         | from being overwhelmed. As the battery "market" gets crowded
         | profit margins will fall and everything will reach an
         | equilibrium.
         | 
         | This is a great demonstration of how capitalism works and why
         | it's beneficial.
        
         | formerly_proven wrote:
         | Negative prices are mostly caused by unreasonable terms towards
         | generation plants. E.g.: requiring the grid to take every kWh
         | generated and paying a fixed price over a 20-year term. This of
         | course encourages capacity to be built with no flexibility. Why
         | not dump your solar power into the grid? You're getting paid,
         | the state guarantees for that... the negative prices are
         | someone's elses problem.
        
         | rcxdude wrote:
         | This is the kind of thing that is funding the massive expansion
         | in renewable energy build-out at the moment. The whole reason
         | there's an energy transition happening is that solar and wind
         | and batteries are cheap enough you can make a lot of money
         | building them, and that'll remain true until basically the
         | whole grid is renewable (finally kicking out the expensive gas
         | turbines), and the average price drops to reach cost of supply.
         | 
         | (And the kind of optimisation that happens with this kind of
         | paper is really in the margins stuff. It generally helps the
         | predictive power of the grid, and usually doesn't make much
         | money once more than one group starts doing it, since it's
         | pretty cheap to run and the margins shrink quickly)
        
       | mellow_observer wrote:
       | A world where individuals are incentivized to use some wasted
       | space to place low maintenance automated trading batteries to
       | make a little money on the side seems like it'd be an interesting
       | solution to the renewable energy storage problem. Put a few units
       | in otherwise useless locations like on roofs or in between
       | highways and make some cash, sounds like a decent investment.
       | 
       | Would there be any expected problems in doing such distributed
       | power storage on a very large scale around the grid that you'd
       | have to account for? Perhaps issues with synchronization, power
       | flow or the possibility of large scale drops in avaialble stored
       | power at times?
        
         | fifilura wrote:
         | Or preferably your EV? Requires no extra space or extra
         | investment...
        
         | soared wrote:
         | Outside of the grid level, maintenance, security, and safety of
         | batteries is important. Many Americans have a garage to
         | securely store their $30k+ car, bike/etc - similar security may
         | be necessary (literally or for the feels) for expensive
         | batteries.
        
       | ic_fly2 wrote:
       | I have programmed batteries / algos to do this in some European
       | markets. This is being done right now.
       | 
       | The yield you could make from batteries in the UK dropped from
       | double digits to 2% in 8months once some hedge funds figured out
       | how to build and bid (or commission companies like my employer)
       | batteries in the UK short term reserve market.
       | 
       | There are a few firms in northern Jutland and London specialised
       | in this sort of trading.
        
         | Horffupolde wrote:
         | That's yield over what base?
        
         | baq wrote:
         | At least the grid is better off and it's not all approximately
         | zero sum...
        
           | bob1029 wrote:
           | I'd make the same argument for the other markets they operate
           | in.
        
             | baq wrote:
             | The REIT ones e.g. are much less clearly positive than this
             | and e.g. the variance swap and co. folks at least have the
             | decency to be so exotic that nobody cares either way.
        
           | friendzis wrote:
           | That's a _very_ bold statement.
           | 
           | Huge part of the reason why negative prices exist in the
           | first place is separation of generation and transmission.
           | With pay-as-clear model negligible-variable-costs generators
           | (i.e. renewables) can bid at zero and pump more into the grid
           | than the _local segment_ can drain, requiring artificial
           | balancing sinks. However, the cost of artificial sinks fall
           | on the grid as transmission costs and are not reflected in
           | the wholesale market.
        
         | azernik wrote:
         | Sometimes the efficient market happens to you (and that's good)
        
         | dschaurecker wrote:
         | Are/where you already trading at a second to sub-second level
         | on the continuous intraday markets? How did you backtest your
         | strategies then, if so? Or is backtesting, e.g. for parametric
         | extensions of the optimization, not yet quite relevant?
        
       | ada1981 wrote:
       | If anyone is interested in Batteries, I highly recommend
       | following NAATBATT.org on LinkedIn and joining their newsletter.
       | 
       | Obama set this org up as a senator to help bring lithium ion
       | batteries supply chain to the US and it since evolved into the
       | trade association for all things batteries.
       | 
       | https://www.linkedin.com/company/naatbatt-international/
        
       | saltspork wrote:
       | In Australia 5 minute spot pricing is now accessible to many
       | residential customers via retailers like Amber electric. With
       | volatile pricing and a large home battery subsidy from the re-
       | elected government, batteries can quickly pay for themselves
       | through arbitrage alone.
       | 
       | EMHASS is an interesting tool to perform the optimisation.
        
         | jakewins wrote:
         | Similarly in Europe; spot market with a big single pay-as-
         | cleared spot auction for every quarter-hour, and then a
         | continuous auction for the same periods closer to delivery,
         | similar to the normal stock market. Millions of residential
         | devices are traded there right now
        
         | philjohn wrote:
         | Yep, been using EMHASS for the last couple of years in the UK.
         | 
         | I have a large array (12.8kWp east/west split) but a low export
         | limit of 5kW. In the winter it's charging overnight at 7p per
         | kWh (Intelligent Octopus Go) and then using that stored energy
         | during the day to avoid importing at peak rates, and in the
         | summer it makes sure to discharge most of the battery before
         | the peak generation hours so that battery charges from power
         | which would otherwise be curtailed (discharge to minimise
         | import on my SolarEdge system, but charge from clipped power
         | would also work).
        
       | potatoicecoffee wrote:
       | seems dumb to have electricity needing to be wasted when there is
       | seawater to desalinate
        
         | Majromax wrote:
         | > seems dumb to have electricity needing to be wasted when
         | there is seawater to desalinate
         | 
         | That's a much more complicated problem. On an energy market,
         | you have only one price to look at, and the battery operator
         | can always buy, sell, or hold energy. The article here talks
         | about optimizing this problem at 5-minute to several-hour
         | intervals.
         | 
         | If you drop excess power into desalination, however, now you
         | have _two_ prices to worry about: energy and water. I also
         | doubt we have 5-minute spot markets for water, so the operator
         | must probably commit to some medium-term water delivery
         | regardless of price.
         | 
         | This means that a desalinating firm takes on much more risk.
         | This might still be profitable, but it's a long-term play based
         | on a deep model of expected energy prices (i.e. knowing that
         | energy is "always" almost free at noon in summer) rather than
         | short-term time-shifting.
        
           | mikeyouse wrote:
           | Desal plants are also extraordinarily expensive and need to
           | operate at very high 'capacity factors' in order to payoff
           | the capital investment that was required to build them.
           | Operating for a a few hours every day because your operating
           | costs are low/negative only works if you don't have a hugely
           | expensive piece of infrastructure depreciating as you wait
           | for those prices to come down.
        
             | amoshebb wrote:
             | could we build them different if the goal is just to waste
             | excess energy?
             | 
             | Why couldn't it just be a giant heating element and some
             | sort of steam condenser at the top and some way to flush it
             | periodically?
             | 
             | It might burn some laughable 3kWh per kg of water, but who
             | cares? every water utility on the coast could add a few
             | megawatts of tea kettles and get opportunistic little
             | splashes of water in volumes small enough they can probably
             | already handle them and the brine discharge would be so
             | small, disperse, and infrequent it'd be easier to deal
             | with, and it'd basically cost nothing
        
               | ema wrote:
               | It doesn't only need to make economic sense now but you
               | also need to be fairly certain that all the battery
               | capacity that is likely to be added to the grid in the
               | future will still allow this to be profitable until your
               | expected break even point.
        
         | Nasrudith wrote:
         | Industrial processes like desalination tend to call for some
         | optimal amount of near 24-7 utilization (barring maintenance
         | and such) for capex reasons and efficiency. You want to use it
         | as much as possible to get the most bang for your buck. The
         | entire reason why there are these excess power periods is
         | because we cannot predict accurately how much power we would
         | really need.
        
         | lazide wrote:
         | Desalination plants _really_ don't like being 'throttled', and
         | are quite capital intensive. Stopping production for any length
         | of time can even destroy the plant, if not done very carefully.
         | Similar for geothermal, though the specific details are
         | different.
         | 
         | Even free power would likely not be worth using if it was
         | sporadic, and it's extremely energy intensive. So that really
         | is saying something.
        
       | brilee wrote:
       | For those of you suggesting we use the extra energy for
       | $pet_topic I suggest reading
       | https://www.moderndescartes.com/essays/factobattery/
       | 
       | Tldr: most applications of free energy have capital costs that
       | far outweigh the free energy harvest potential.
        
       | thelastgallon wrote:
       | Just use EVs. EVs are primarily energy storage devices, some
       | people get to drive them about 20 - 30 mins/day. The remaining 23
       | hours, it is a energy storage device. It can absorb excess power
       | when price is negative, and can even supply power back to the
       | grid when prices are high!
        
         | bee_rider wrote:
         | This seems like building more batteries (just, with extra
         | hardware).
         | 
         | An EV could be good for this sort of thing, but I guess it
         | would have to sit around at less than 100% charge, to have the
         | capacity.
        
           | bufferoverflow wrote:
           | We almost never charge our EV to 100%, to not degrade the
           | battery faster.
        
             | bee_rider wrote:
             | But, if you are going to offer "absorbing energy from the
             | grid as a service" the capacity you have to offer can only
             | be                 <absolute max that you are willing to
             | charge your battery to> - <minimum that you are willing
             | have your battery sitting at>
             | 
             | There definitely could be some gap there, but it does
             | depend on the car sitting at less than "full" (however you
             | define full).
        
         | two_handfuls wrote:
         | Yes, exactly this has been proposed with "smart car chargers,"
         | along with other things you can do if the grid operator has
         | some control over a bunch of grid-connected equipment. It
         | hasn't taken off as far as I know, probably because that means
         | the car battery wears out more.
         | 
         | The "virtual power plants" are the closest thing to this idea
         | that is actually done in practice. That's individuals who own
         | batteries joining some collective that then sells to the grid
         | the ability to reduce demand a bit. Tesla did a pilot program
         | with its Powerwalls iirc.
        
         | rafaelmn wrote:
         | Sounds like deprecating a >10k battery pack on a >30k vehicle
         | and reducing your max range with power cycles to earn pennies.
        
           | thelastgallon wrote:
           | Its more than pennies[1]. By several orders of magnitude. Car
           | batteries now last longer the rest of the car lifespan, it
           | will be millions of miles soon.
           | 
           | Tesla Electric customers report making as much as $150 a day
           | https://electrek.co/2023/07/05/tesla-electric-customers-
           | repo...
        
             | rafaelmn wrote:
             | Lol at 5$ per kWh.
             | 
             | In my country for home consumers the difference between
             | day/night rates is 10-20c/kWh. With spot pricing I can see
             | it working to cover the post commute power spike - but
             | you're effectively doubling your commute discharge rate and
             | pushing charge levels to suboptimal levels.
             | 
             | Batteries might work but at 80% capacity they are worth
             | significantly less than new - both in terms of utility and
             | resale value.
             | 
             | Maybe if battery range gets extended so far that even at
             | 80% capacity it's an overkill - like 1000mile batteries - I
             | could see myself doing something like this - but at current
             | ranges and charging setups - I'll skip the few dozen euro a
             | month.
        
               | gpm wrote:
               | On the other hand battery prices are dropping
               | exponentially. There's a good argument to be made that
               | your battery is a depreciating asset not (just) because
               | it's degrading, but because the technology is getting
               | cheaper, and thus you should extract as much value from
               | it as possible as quickly as possible (and then replace
               | it).
               | 
               | The caveat to this market is who knows how much of a
               | premium you'll end up paying to replace the battery given
               | that it's attached to a certain model of car.
        
               | rafaelmn wrote:
               | > On the other hand battery prices are dropping
               | exponentially.
               | 
               | Are they ? I keep hearing this but in practice the price
               | of an EV is still dominated by the battery pack and the
               | movement in EV prices is anything but exponential. China
               | started pushing out the affordable EVs but that's because
               | they are using less efficient/cheaper chemistry and even
               | with better packaging they are significantly less energy
               | dense.
               | 
               | I've seen Toyota announce 1000 miles solid state battery
               | - if battery tech was dropping exponentially that should
               | be cheaper than ICE in a few years - I would take the
               | opposite side of that bet.
        
               | gpm wrote:
               | Yes, they are: https://assets.bbhub.io/professional/sites
               | /24/battery11.jpg
               | 
               | China's LFP battery packs, as of 2022, have a density of
               | 160 Wh/kg [1], which matches the NMC battery pack in a
               | Model Y from the same year [2] (Note: The Model Y battery
               | pack was no doubt designed and built earlier given that
               | it was already in a product). I.e. is isn't really the
               | case that the batteries they are putting in are less
               | efficient than the earlier iterations. Though you could
               | have even high energy density batteries if you didn't
               | switch to LFPs.
               | 
               | I'm not sure we are racing towards 1000 mile cars,
               | because I'm not sure it's the case that there's a huge
               | market for 1000 mile cars, and there's limits on density
               | short of technological leaps that would make such
               | vehicles heavy. I think we're rather more likely to see
               | 600km cars just keep dropping in price instead.
               | 
               | [1] https://insideevs.com/news/576870/catl-third-
               | generation-ctp-...
               | 
               | [2] https://www.batterydesign.net/2022-tesla-
               | model-y-4680/
        
         | woda79 wrote:
         | That is a great thought and there is a lot of research in using
         | batteries of vehicles for grid stabilization as well as
         | arbitrage trading.
         | 
         | The problem, however, is that a lot of plugged vehicles are
         | required to guarantee a meaningful amount of firm power/energy
         | capacity and owners typically do not want to sacrifice a lot of
         | flexibility when they rent out their batteries to provide such
         | services.
         | 
         | Furthermore, as you can see from the replies, many are scared
         | about battery degradation. Because of this and due to the fact
         | that reverse charging is not possible for most vehicles, this
         | schemes are often restricted to delayed charging which further
         | limits revenue potential.
         | 
         | However, using arrays of old car batteries as stationary
         | batteries is a very viable idea that, in my estimation, will
         | lead to a significant growth in installed BESS in a couple of
         | years.
        
       | jillesvangurp wrote:
       | Battery production rates are creeping up to multiple twh/year
       | now. This is accumulating to a lot of battery sitting around in
       | vehicles, domestic storage, grid storage, etc. Mostly the goal of
       | these batteries of course isn't supporting the grid but some
       | other use case. But if it's plugged in, it could potentially be
       | available for selling power. Right now, most EVs can't contribute
       | power. But that's something that is starting to change. Small
       | experiments with thousands or tens of thousands of vehicles have
       | already been done and seem to work fine. Now imagine tens of
       | millions of vehicles being part of the grid. That's a serious
       | amount of stand by power for absorbing excess power or
       | dispatching power when needed.
       | 
       | Another interesting aspect is that as grid demand fluctuates, a
       | lot of cables are under utilized at least some of the time. Which
       | means there is plenty of capacity for charging batteries provided
       | there is excess generation and cable capacity. A lot of that
       | power currently gets discarded instead. Batteries allow better
       | use of this excess power. And having a lot of local battery means
       | that cable capacity can be freed up as well when needed and then
       | recharged when demand reduces.
       | 
       | And then finally battery prices are coming down. With sodium ion
       | cell production ramping up in several places, things could get
       | quite a bit cheaper. These don't depend on scarce metals or
       | materials. And they last quite long as well (relative to NMC).
        
         | mschuster91 wrote:
         | > That's a serious amount of stand by power for absorbing
         | excess power or dispatching power when needed.
         | 
         | ... and a serious issue should one of the few large
         | manufacturers or remote-control dispatcher/trader companies get
         | hacked. The outage in Spain a few weeks ago was just a small
         | warning, probably caused by a technical malfunction. But now
         | imagine this being used as a side track in an act of war? The
         | first day of the Russian invasion of Ukraine was accompanied by
         | the hack of Viasat satellites, which led to 5.800 wind turbines
         | shutting down due to a lack of remote control capabilities [1].
         | Now imagine the large Chinese inverter and power bank
         | controller vendors that often enough just white-label for other
         | brands? That's a whole lot of a different game now.
         | 
         | [1] https://en.wikipedia.org/wiki/Viasat_hack
        
           | toast0 wrote:
           | > and a serious issue should one of the few large
           | manufacturers or remote-control dispatcher/trader companies
           | get hacked. The outage in Spain a few weeks ago was just a
           | small warning, probably caused by a technical malfunction.
           | 
           | If everyone agrees, you can use grid frequency/phase to
           | coordinate, and not a separate realtime communication system.
           | Grid interactive demand/response is a proven way to manage
           | supply and load.
           | 
           | When your section of the grid is stressed, supply power or
           | abstain from charging; when your section of the grid is
           | abundant, charge.
           | 
           | Coordination is useful too, of course; predictive charging is
           | helpful, and you wouldn't get that only by monitoring the
           | grid; you also want to know somehow that a supply or load is
           | scheduled to be added or removed at time X, or was
           | unexpectedly removed and will not be reconnected for some
           | time. And the system operator would want to know about
           | capacity in many dimensions.
        
             | mschuster91 wrote:
             | It doesn't work that way. Maybe in the US where everyone
             | seems to do their own shit, particularly in Texas, but here
             | in Europe our grid literally spans the _entire continent_ ,
             | from Portugal through into Ukraine's front lines, and from
             | Norway even down towards Africa. It's a three phase grid
             | that is in synchronized phase everywhere. Like, literally
             | everywhere.
             | 
             | Grid frequency cannot be used at scale to coordinate energy
             | production as a result, because the grid elements
             | themselves don't know _why_ the frequency is going down on
             | its own or where the cause is. For that you need to monitor
             | the country or region crossing to see where energy is
             | flowing and aggregate this.
             | 
             | Drop a couple gigawatts from the production side, for
             | example, all at once and the frequency will immediately
             | drop, only not crashing due to the mechanical inertia of
             | the large power plants. Immediately, electricity and
             | physics will lead to current balances redistributing and
             | automated systems will kick in (e.g. gas peaker plants ramp
             | up in a matter of seconds, battery storage kicks in even
             | faster). But when too much capacity gets dropped, the
             | available spare capacity isn't enough and eventually the
             | first lines will trip due to overcurrent or frequency
             | deviation. That is what happened in Spain, made worse by
             | the fact that inverters don't have mechanical inertia and
             | so immediately _more_ inverters dropped out for safety
             | reasons as the frequency sagged too much for their
             | protection circuits. The inverse, adding a couple of
             | gigawatts of consumers, causes the same effect.
             | 
             | That's also why very large consumers such as smelters must
             | contact the local electricity distributor in advance before
             | any load change - dispatch must know precisely when the
             | consumer will drop or add load, so that other plants can be
             | regulated up or down to avoid too much of a sag or hike in
             | frequency.
        
               | Symbiote wrote:
               | Minor, but it's from Denmark (Jutland) south.
               | 
               | There's a separate Scandinavian grid for East Denmark
               | (Zealand) and north.
               | 
               | (And the British Isles are their own grid.)
        
               | mschuster91 wrote:
               | Yeah I knew about the Brits but you're correct, it
               | escaped my mind that the Nordics run their own zone [1].
               | But you're a bit outdated too, turns out - the most North
               | point is the Baltics these days, they switched away from
               | the Russian grid a few months ago [2].
               | 
               | [1] https://de.wikipedia.org/wiki/Verband_Europ%C3%A4isch
               | er_%C3%...
               | 
               | [2] https://www.entsoe.eu/news/2025/02/09/entso-e-
               | confirms-succe...
        
           | jillesvangurp wrote:
           | Of course the Ukrainians are now much less dependent on
           | central power generations out of necessity. It turns out that
           | all those big power plants and electricity distribution
           | centers make for nice drone targets. The Russians did far
           | more damage with that than with their satellite hackery.
           | Those 5800 wind turbines came back online and are mostly
           | still operational.
           | 
           | The lesson here is that distributed power is a good thing in
           | war time scenarios but you might want to pay attention to
           | digital security. Central power generation becomes a tempting
           | target.
           | 
           | Now the good news with Chinese stuff is that a war is not
           | imminent and we have the benefit of hindsight and can do
           | something about that.
        
             | mschuster91 wrote:
             | > Now the good news with Chinese stuff is that a war is not
             | imminent and we have the benefit of hindsight and can do
             | something about that.
             | 
             | We are and we have been at war with China (and Russia and
             | North Korea, fwiw) for many years at this point. The
             | ongoing cyberwarfare from either country is more than
             | enough to warrant this label, the problem is we were and
             | are governed by chickens who refuse to accept the reality
             | we are living in and still think that kowtowing to China's
             | every demand will save our economies.
        
         | HankB99 wrote:
         | > A lot of that power currently gets discarded instead.
         | 
         | How is power discarded? I would expect peaking generation to be
         | cut back or perhaps even base load plants can reduce output.
         | (AFAIK "base load" means they are expected to be kept operating
         | continuously whereas "peaking" is designed to start up when
         | needed and shut down when not.)
        
           | qeternity wrote:
           | > How is power discarded
           | 
           | It isn't, not at scale in any traditional sense.
        
           | jillesvangurp wrote:
           | wind mills are weather vaned (i.e. not broken, but
           | deliberately turned off), solar panels excess energy is
           | curtailed (prevented from going into the grid) and usually
           | transformed into heat on the panels or in inverters.
           | 
           | As for baseload. It's one of those waffly terms that's rarely
           | specified in GW that is needed. Which as it turns out is far
           | less than we used to have given that much of it was replaced
           | with wind and solar over the last decade or so. The real
           | question is how low can we go with this stuff before we need
           | some more solutions. Some would say all the way but the
           | consensus is that the last 5-10% might get very hard and
           | costly.
           | 
           | Either way, having some peaker plants on stand by ready to
           | spin up over the course of hours/days while batteries slowly
           | deplete is probably a good short term compromise. Replacing
           | spinning mass (fly wheels) with batteries seems a
           | particularly popular and very cost effective use for
           | batteries.
        
         | giantg2 wrote:
         | "Right now, most EVs can't contribute power"
         | 
         | Nor should they. People don't want to be cycling their
         | batteries and reducing their life. This use case would be
         | better served by batteries that are designed for that purpose
         | instead of being designed to be light for a vehicle.
        
           | wjnc wrote:
           | Future: Cycle the power when profitable, replace the
           | batteries when depleted enough? Batteries in cars are many
           | times the domestic demand of a given home, at least in
           | temperate climates.
        
           | tomas789 wrote:
           | They are almost the same batteries. Different form factor but
           | same thing. They are rolled from the same lines.
        
             | giantg2 wrote:
             | Grid level batteries use many different forms. You even
             | have stuff like pumped hydro and controlled drop concrete.
             | Even if the battery cells are exactly the same, the
             | replacement cost is much higher in a vehicle due to the
             | configuration.
        
           | inetknght wrote:
           | > _People don 't want to be cycling their batteries and
           | reducing their life._
           | 
           | More battery cycles just costs money. For the right price,
           | I'd do it.
           | 
           | But more than that: I don't want to be stranded without power
           | in my vehicle because someone in the electric grid made poor
           | power management decisions and decided to offload that
           | decision to consumers.
        
             | eldaisfish wrote:
             | as with anything, it's not just money. Losing battery
             | capacity in an EV is a hassle. A hassle because you charge
             | more frequently, a hassle because you will eventually need
             | a battery change, and so on. What is the price of all that
             | hassle?
             | 
             | That said, most EV incentive programs use around 10% (often
             | less) of an EV battery capacity so the actual effects are
             | barely noticeable.
        
               | crazygringo wrote:
               | > _What is the price of all that hassle?_
               | 
               | A price that can be measured in money. How much more does
               | it need to pay to be worth any extra hassle?
               | 
               | So in a sense it _is_ just money. Money _is_ hassle,
               | fundamentally. It 's a hassle to make it and you spend it
               | to save other hassles.
        
               | Dylan16807 wrote:
               | And since lots of EV batteries seem to lose capacity very
               | slowly after the first 10-15%, and you can keep your
               | battery trading in the happiest range, there's a lot of
               | potential for the extra hassle to be worth the paycheck.
        
           | usefulcat wrote:
           | In general I agree with that, but I think it really would
           | depend on the price. For at least some people it would surely
           | be worthwhile for the right price.
        
             | giantg2 wrote:
             | If the price is high enough, EVs still lose out since you
             | can make more profit creating battery farms with cheaper
             | batteries that are cheaper to replace. You can't make it
             | expensive enough to cover the replacement of a Tesla
             | battery without making it attractive enough for someone
             | else to use ea more efficient model.
        
               | wongarsu wrote:
               | That assumes that EV batteries are used to 100% and will
               | reach end-of-life together with the rest of the car or
               | before the rest of the car. That is increasingly untrue.
               | If your EV battery would outlive your car then you can
               | use some of those "extra" cycles at very low marginal
               | costs (until there is an efficient market for used EV
               | batteries for old cars).
               | 
               | Another factor is that not all charge/discharge cycles
               | are the same. Going between 60% and 80% five times is a
               | lot lighter on the battery than going between 0% and 100%
               | once. Which pairs great with EV batteries, because their
               | batteries are deliberately oversized compared to average
               | use to account for uncommon events.
        
           | schiffern wrote:
           | EV can grid cooperate without adding charge/discharge cycles.
           | You just intelligently schedule the charging.
           | 
           | This is how most Time-of-Use metering already works. The
           | driver sets a minimum battery percentage to charge
           | immediately (eg 40% range, enough to reach the local
           | hospital), and then schedule a time when the car should be
           | fully charged (eg 80% by 7AM). The software just Does The
           | Right Thing, using the same prediction and bidding algorithms
           | as stationary batteries.
           | 
           | The search term is "V1G" (a cheeky reference to
           | _unidirectional V2G_ ).
        
             | SirFredman wrote:
             | Indeed. I live in The Netherlands and use the Jedlix app to
             | schedule charging, which works in this way. The grid
             | operator can use this to selectively create or shed load in
             | a specific area, which helps to stabilize the grid. Really
             | nifty.
        
         | GuB-42 wrote:
         | Even without talking about batteries, I think a lot can be done
         | using smart grids. For example, your A/C and heaters can run a
         | little later or a little earlier, it won't have a significant
         | effect on your room temperature, especially if your house is
         | well insulated. It means a lot can be done just by remote
         | controlling thermostats with minimal effect on confort. This
         | can apply to other appliances that are not too time sensitive
         | or can have a delayed start, like washing machines,
         | refrigerators, dishwashers, etc... but thermostats are likely
         | to be the biggest ones.
         | 
         | As with batteries, it would require some work with the utility
         | companies, so that they can signal the best times to power
         | on/off, and offer the appropriate financial incentives to do
         | so. We are already doing that in some way with peak/off-peak
         | pricing, but it doesn't help with high frequency, unplanned
         | variations.
        
       | Aeroi wrote:
       | pretty sure nodal energy market trading, duck curve arbitrage is
       | the whole profit play for the tesla power wall/autobidder and the
       | Base Power startup coming out of ERCOT. There is definitely a
       | land rush from energy firms and GIS guys to front run land
       | purchasing near solar buildouts and to build as much grid scale
       | battery storage as possible. The percent swings can be huge. Also
       | a huge rush for this in the Northeast now that the offshore wind
       | contracts have been cancelled.
        
         | ccheney wrote:
         | I find Autobidder fascinating, they've been at this for awhile.
         | When I saw this HN post I thought the paper may have come from
         | Tesla themselves.
         | 
         | https://www.tesla.com/support/energy/tesla-software/autobidd...
         | 
         | https://www.tesla.com/support/energy/tesla-software
        
       | msgodel wrote:
       | Energy futures you say? Oh boy I've heard this one before...
        
         | NooneAtAll3 wrote:
         | explain?
        
           | msgodel wrote:
           | That's what the infamous company Enron was running:
           | simultaneous energy futures brokerage and market making.
           | Their market making part blew up and they hid it from
           | everyone for a while until the rest of the company did. It
           | was a massive scandal. It was pretty similar to what FTX was
           | doing just with energy instead of crypto.
        
         | Dylan16807 wrote:
         | That kind of association is why you can buy futures in just
         | about every crop _except_ onions. The fact that you can
         | structure fraud around a specific kind of future doesn 't make
         | them special or a bad idea. One major fraud should not bias us
         | forever.
        
       | dschaurecker wrote:
       | Thank you all for the interest in our paper, it is cool to see
       | that people are interested in the topic!
        
       | b0a04gl wrote:
       | > "Our method is able to solve over 24 million optimization
       | problems in less than 90 minutes."
       | 
       | that line is doing heavy lifting. sounds insane until you look
       | closer they batch out embarrassingly parallel, lowdimensional
       | problems no live latencies, no network I/O, no grid API jitter.
       | just hammering a static dataset in memory. real markets stall,
       | disconnect, price slippage, queue delays. none of that here. so
       | yeah, 24 million looks cool in the abstract, but under the hood
       | it's just cleanroom compute; feels like they optimised the
       | benchmark more than the actual system
        
         | loehnsberg wrote:
         | Assuming you add all the annoying details that algo trade
         | execution brings, the algorithm still provides the answer on
         | which position to take within a few microseconds, which is what
         | you want if you trade in a limit order book.
        
           | b0a04gl wrote:
           | true, you want microsecond decisions at the core, no doubt ;
           | but that's only half the game. an ideal action in clean
           | memory isn't the same once it hits fragmented liquidity,
           | stale quotes, partial fills. if the algo doesn't account for
           | execution drift or book pressure post-placement, the
           | microsecond edge fades fast. so yeah, fast compute's
           | necessary but not sufficient without modelling the messy tail
           | end too
        
       | julienb_sea wrote:
       | Energy overproduction is going to become a serious viability
       | problem for baseload generators, which in time will significantly
       | affect grid reliability. Rolling blackouts will become the norm
       | unless we figure out a serious scalable solution to this.
        
       | adds68 wrote:
       | https://octopusenergy.group/kraken-flex This is already being
       | done at an industrial scale in the UK
        
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