[HN Gopher] Engineer's solar panels are breaking efficiency records
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Engineer's solar panels are breaking efficiency records
Author : belter
Score : 102 points
Date : 2024-06-15 16:25 UTC (6 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| ziggy_star wrote:
| The super efficient ones are the panels they send to space. This
| is just like with chips, all about yields and price/performance.
|
| I would not hold your breath for the typical consumer panel to
| improve much beyond 20%-25% any time soon sadly.
|
| It does generate a lot of hopeful breathless articles which rubs
| me the wrong way. It is important to stay realistic in the search
| for solutions.
|
| Solar is already great and cheap and there are lot more wins
| possible in the actual deployment as most of the cost is now
| overheads, bureaucracy, labour, 'etc.
| GlibMonkeyDeath wrote:
| It's not a breathless article - these advances are quite doable
| from an engineering standpoint (and going from 20-->25% is a
| HUGE deal - that directly reduces the number of panels needed,
| and so directly reduces overhead and labor.)
|
| The more exotic designs which often _are_ the subject of
| breathless articles (e.g. perovskite
| https://en.wikipedia.org/wiki/Perovskite_solar_cell or other
| multi-junction cells) can get greater efficiencies (like up to
| 40% for quad junction) but are a lot more expensive from a
| lifetime cost perspective (they don't last nearly as long as
| silicon junctions and are much more expensive to produce.)
| ziggy_star wrote:
| I will of course happily buy a 25% panel as soon as it is on
| the market if the price per watt for the total install is not
| soaked up by a multitude of other factors.
|
| When can I expect that to be?
| IshKebab wrote:
| I don't know if it's _that_ huge of a deal. The main
| challenges of solar are not the number of panels now. The
| incremental cost of installing an extra panel is quite low.
|
| The biggest challenges are storage, and - in the UK at least
| - nimbyism. (Yes people really object to solar panels in
| fields.)
|
| The other thing I would say is that the software for solar
| inverters is way behind where it could be. You could easily
| get a 10% improvement just by making them smarter - e.g.
| using time series prediction, day ahead pricing, etc.
|
| Unfortunately they're stuck in the stone ages. I have a
| QCells inverter (rebranded Solax) - do not buy btw - and they
| directly told me they are not interested in any of this smart
| stuff.
|
| They also do automatic firmware updates with no opt-out and
| no notification of changes. And the updates include
| _removing_ features.
|
| Do not buy QCells solar! (Hopefully Google finds this.)
| jpgvm wrote:
| IMO with solar it makes the most sense to stick to high
| volume Chinese stuff.
| Longi/Jinko/Trina/CanadianSolar/whatever for panels and
| Deye for inverters. The Deye stuff is particularly good
| because of aforementioned smart features, especially if you
| are off-grid or operate on crappy rural power.
|
| My favourite feature is called peak-shaving where it uses
| the battery to supplement said crappy rural power or a
| generator that is provisioned for average load instead of
| peak.
|
| I haven't found inverters with similar features and
| configurability anywhere else thus far.
| justahuman74 wrote:
| Lots of people have limited roof space that isn't in shade
| for parts of the day. If we're able to cheaply over-
| provision the panels on the roof then that mean less
| reliance on the grid (if you use batteries)
| dogma1138 wrote:
| That's not very correct the new ISS solar panels for example
| have a 12% efficiency they are optimized for longevity and
| weight.
|
| The relatively high efficiency figures often touted for some
| spacecraft panels especially in low earth orbit don't compare
| apples to apples as they include the additional 70-80% solar
| radiation that isn't absorbed, reflected or scattered by the
| atmosphere.
|
| There are some spacecraft that do use multi-junction cells with
| very high efficiency however those are ones which are sent far
| into the outer solar system like Dawn and Juno.
| szvsw wrote:
| > "Gaining 1 or 2 percent more efficiency is huge. These may
| sound like very tiny increases, but at scale these small
| improvements create a lot of value in terms of economics,
| sustainability, and value to society."
|
| It's so easy to forget this and the massive scale and its
| relevance at the massive scale of the systems we need to (and
| are, to some extent) roll out. It also seems promising when these
| breakthroughs are happening in R&D groups of industry players
| trying to dogfood it rather than in labs.
|
| At the same time though, it's starting to feel to me, to some
| extent, like we have _kind of_ solved solar? It's everything else
| around it that needs to advance, particularly grid infra,
| batteries and electrifying the general class of difficult-to-
| electrify problems (steel, concrete, freight). I might be totally
| off-base and blinkered with that assessment.
|
| Edit: I guess I should try to clarify my feeling after reading
| some of the responses below: it feels like solar tech is not
| really the limiting factor in renewable scaling, and that
| advances in solar efficiencies won't _drastically /meaningfully_
| simplify the other challenges/limiting factors we currently face
| (grid infra/batteries, electrification of mfg, duck curve, etc).
| Children point out that space and cost savings from efficiency
| gains in solar may still be significant at grid scale though!
| Still, this is very cool progress to read about!
| bluefirebrand wrote:
| Completely agree. I'm sure there's still a lot of advances left
| in solar panels themselves, but we really do need to solve the
| grid, solve storage, essentially solve the base load
|
| We won't be able to transition fully off of fossil fuels until
| we do
| Kye wrote:
| I wonder if someone has done a science to compare the carbon
| impact of batteries and peaker plants. It might be that a
| lesser of evils fossil fuel _is_ the solution if it 's a
| sometimes thing and not the main thing. It also has the virtue
| of being supplyable in a renewable way with landfill gas
| recovery.
| Tade0 wrote:
| A battery made using the dirtiest grid that produces them at
| scale (110kg CO2/kWh of battery) breaks even compared to gas
| after ~200 cycles.
|
| LFP batteries commonly used as stationary storage regularly
| do 2000 cycles.
|
| Makes more sense to use that gas to make more batteries.
| mrtracy wrote:
| Peaker plants are considerably less efficient than base load
| gas energy, because the constantly running plants use a
| _combined cycle_. In both types of plants, the fuel is burned
| in a gas turbine to directly generate power; however, in the
| combined-cycle plant the waste heat from this is used to
| generate steam to run steam turbines, capturing additional
| power; this actually generates over twice as much useable
| energy per unit of fuel. Peaker plants cannot effectively use
| this mechanism as it has a much longer start-up time.
|
| Combined cycle is a major reason that gas power plants are so
| attractive; the inability to use it in Peakers is a reason
| why they are so _unattractive_.
| Dylan16807 wrote:
| > Peaker plants cannot effectively use this mechanism as it
| has a much longer start-up time.
|
| How much longer? If a plant is designed with a big priority
| to getting secondary generation up to speed quickly, how
| many hours will it need to warm up?
| crote wrote:
| A lot of it depends on the exact type of usage, does it
| not?
|
| Currently a lot of peaker plants operate a bit like "A
| power line failed, we need extra power NOW!" They get
| essentially zero warning and are expected to be at full
| power within 30 minutes. Dealing with that obviously leads
| to some issues, but in 2024 we could also fill that niche
| with battery storage.
|
| When it comes to the energy transition, it's a bit of a
| different problem. We can reasonably predict weather, so
| the rough output of solar and wind is known several days in
| advance. If the forecast is predicting an overcast day with
| zero wind, any "peaker" plant will have tens of hours to
| warm up. Combine that with minor changes to reduce startup
| time[0], and it seems far less of a hurdle to overcome.
|
| [0]: https://etn.global/wp-content/uploads/2018/09/STARTUP-
| TIME-R...
| hamandcheese wrote:
| In general I agree. But every efficiency gained will translate
| to less land used for solar, or a longer period of energy
| surplus every day (which means less deficit that has to be made
| up in other ways during the non-peak hours). Either of those
| things make me happy.
| ziggy_star wrote:
| A manufacturing efficency would, this won't. The cheapest
| panel wins.
| tromp wrote:
| Not necessarily the cheapest, but the one with the best
| combination of efficiency, cost, durability, and possibly
| other properties I'm overlooking.
| ziggy_star wrote:
| I meant in the marketplace as bought by actual consumers.
| So, the cheapest.
| szvsw wrote:
| Isn't GP effectively saying $/W? I assume that's how
| _most people_ evaluate price... "I want to install a
| system that will pay itself back in the smallest amount
| of time while staying below my max budget."
| ziggy_star wrote:
| That would be the prosumer. A consumer buys the thing
| with the lowest sticker price. See for example triple
| pane vs single pane windows.
| szvsw wrote:
| I guess be careful how you use prosumer in this kind of
| thread, since it often might refer to a producer-consumer
| (ie someone who can get paid $$ to export energy back
| into the grid, as opposed to just saving $$ from avoided
| grid import).
|
| I assume you meant professional consumer.
|
| > See for example triple pane vs single pane windows.
|
| Bad example but I understand your point. Bad example
| because it takes significantly more expertise to model
| the savings from triple paned window with low-e coating
| and vacuum sealing vs double paned vs single paned (ie it
| requires a proper building energy model in eg
| EnergyPlus). Also bad because the triple paned window
| might be immediately disqualified by the budget
| constraint above. In any case, I think you are just
| saying people are likely to pick the thing which has the
| least friction, whether that friction comes from cost,
| installation challenges, etc etc.
|
| And yes, sometimes upfront cost is the most significant
| thing which affects people's willingness to adopt a
| certain home energy retrofit but payback period does play
| a big role in people's decision making, as well as their
| ability to get funding for it (government rebates), or
| they may simply be going with an installer who pays them
| to install it and they certainly care about payback
| period!
| ziggy_star wrote:
| > Bad example because it takes significantly more
| expertise to model the savings from triple paned window
| with low-e coating and vacuum sealing vs double paned vs
| single paned (ie it requires a proper building energy
| model in eg EnergyPlus). Also bad because the triple
| paned window might be immediately disqualified by the
| budget constraint above.
|
| I'm confused by this as that is exactly the point made.
| :)
|
| I was watching a NASA iTech talk if memory serves about
| vacuum windows. He opened with an overview of the market
| and adoption trends and was quite flustered. Small
| market, little in the way of R&D and many challenges in
| manufacturing them in the US.
|
| One of the things that flustered him is being told by
| sales reps that those types of windows are "pointless and
| not worth it" and so on. Digging deeper the reason he was
| steered away from them is simply because they were up not
| as lucrative to sell in that moment at time for that
| provider. I can try and dig that up if you want as I
| recall this anecdote vividly and my thinking diverged
| from yours in that moment.
|
| Turns out most people have no idea what any of it means
| you see? So indeed friction, perverse incentives,
| financing, lack of consumer education and so on. Some
| terribly sad amount of people still opt for single pane
| instead of double which shouldn't make any kind of sense.
|
| Remember also that people often move houses. Anyway the
| upfront cost ended up dominating rather than the payback
| period. Folks aren't that rational or liquid.
|
| Out of curiosity try modeling it out and pitching it as a
| choice if you know anybody looking;
|
| Chinese panels <20% efficiency, cost X, payback period Y
| vs Unobtanium panels 25% efficient, Cost X+, Y++.
|
| But don't try to steer them or mention the payback period
| unless asked. It isn't as straightforward as we would
| hope.
| szvsw wrote:
| > I'm confused by this as that is exactly the point made.
| :)
|
| Sorry, I was trying to indicate that it is significantly
| simpler for a random uninterested or mildly-interested
| consumer to evaluate the cost-effectiveness of solar than
| it is windows. Most people have a good sense of how much
| their energy bill costs, and there are plenty of cheap
| and free tools which let you accurately estimate how much
| energy you will save from a PV system, but even basic
| mental math is enough. As opposed to windows, which are
| significantly more complicated because they involve
| thermodynamic modeling of your home.
|
| You should read recent work by Zachary Berzolla, who is
| now working in Maryland's department of energy on their
| commercial buildings decarbonization program. His MIT PhD
| dissertation is specifically about willigness-to-pay for
| home energy retrofits (but especially heat pumps). Not
| sure if it has been posted to DSpace yet but I believe
| some various conference/journal papers are online
| already.
| bradknowles wrote:
| Unfortunately, I think a lot of people don't really know
| how much their power costs. They just pay the bill they
| are sent, maybe even on autopay and they don't even look
| at the statements when they come in.
|
| So, they don't know how much their power costs, and they
| don't have a clue how much solar would cost to buy,
| install, run, etc... and how that compares to the payback
| period over time, etc....
|
| These are the people that I think we need to reach.
| szvsw wrote:
| > They just pay the bill they are sent, maybe even on
| autopay and they don't even look at the statements when
| they come in.
|
| On the other hand there are a significant number of
| people who are energy-burdened, and they often have the
| most inefficient homes (leaky or non-existent sealing,
| little insulation, old appliances, etc). These homes
| often have the least ability to take advantage of
| government rebates since they may only be tax rebates
| while the retrofit still requires up the upfront cost to
| be paid. At the same time, high-income homes, though
| often much more efficient, also often use the most energy
| (since floor area tends to grow with home owner income,
| and space conditioning/electric requirements tend to grow
| with floor area). It's easy to design incentive programs
| which have a big carbon impact but a bad equity impact in
| that they just end up giving money to people who would
| already be upgrading their homes without the rebates.
|
| The person who knows just how much money they are
| spending on their bill every month will likely value the
| savings much more (ie the utility value of the savings
| are much higher), but they may also have far less
| awareness of the kinds of programs available to them for
| retrofitting their home or installing PV.
|
| It's a complicated problem, figuring out who to reach and
| how to drive adoption while balancing decarbonization and
| equity!
| kragen wrote:
| no, more efficient solar panels at a given price mean cheaper
| energy, which means it becomes economical to use more energy,
| until you run out of ways to use energy usefully. usually the
| increase in energy demand is more than enough to increase the
| use of inputs, a fact known as the 'jevons paradox'
| Angostura wrote:
| The better the solar gets, the bigger the incentive to
| restructure the surrounding infrastructure
| phkahler wrote:
| Percentages can be funny. 2 percent higher efficiency is 10
| percent more output if you go from 20-22.
| hinkley wrote:
| If the costs aren't too egregious that can affect the break
| even point quite a bit.
|
| And the situation with embodied carbon footprint. Which we
| pointedly do not talk about.
| Filligree wrote:
| That would be two percentage points. Two percent, I would
| expect to be from 20 to 20.4%.
| Izkata wrote:
| Technically correct but not colloquial usage. GP got that
| scale right, except they've actually managed going from
| around 20% to around 25%.
| mensetmanusman wrote:
| No, we have not. Half of the current cost is due to
| installation and labor, so any weight reductions will have a
| huge impact on cost. Perovskite solar cells have the
| opportunity to have a 10 X weight reduction.
| Denvercoder9 wrote:
| How much of that cost is related to the physical handling of
| the panels themselves, and not the electrical installation,
| though? Weight reduction isn't going to help there.
| mensetmanusman wrote:
| It's propagates through the supply chain, loading,
| logistics, wear on vehicle transport etc.
|
| We should practically get to the point where someone can
| buy a roll of material at Home Depot and unravel it on
| their roof, nail it, and plug it in themselves.
| lompad wrote:
| The currents and voltages involved are going to make that
| a non-starter. Do you really want random people messing
| with those? The solar inverters are also sized that big
| for a reason.
|
| At least in countries with strong regulations around
| working with electricity this is simply not going to be
| feasible.
|
| I've been in the PV business for some time now and seen a
| person get killed by it. It's not pretty. Still
| remembering that smell of burnt flesh... Now, to be fair,
| that was at a 12MW-installation, not on a roof. But
| still...
| thechao wrote:
| Jay Leno talks about installing solar on his house (which
| he did himself) and commenting that he was getting
| shocked a lot, bc as soon as the PVs are in the sun,
| they're making electricity. He said it made handling the
| units tricky.
| ethbr1 wrote:
| Stupid question I've been curious about.
|
| What happens to a PV panel, receiving sunlight, with no
| load?
|
| Does it degrade or suffer ill effects in any meaningful
| way? Or does it just have a potential between its outputs
| but otherwise isn't impacted?
| lompad wrote:
| A small current is going to flow internally, but nothing
| else happens. It's quite normal to have solar panels
| running with zero load in regions with lots of PV -
| reason being, that the carriers need to keep their
| electricity nets stable and have to carefully balance
| electricity entering and leaving the net.
|
| At least in Germany, every PV installation of certain
| size (> 30kW peak) is mandated to be able to be shutdown
| remotely by the carrier if you supply electricity for the
| net and aren't just using it for yourself. (You get paid
| the same during shutdowns, just like it were running.
| Otherwise it would be quite damaging and likely reduce
| adoption of PV)
|
| Point being: no, it doesn't hurt the panels and is a
| regular ocurence.
| antisthenes wrote:
| The generated power will be dissipated through the panel
| as heat, AFAIK.
|
| Which means that in winter, probably nothing, because
| it's cold, but on a hot summer day with peak sun, the
| heat might start damaging the cells. How much exactly
| you'd have to look at studies.
|
| My guess is the output will permanently degrade by a few
| % per year if the panel is not connected. Might go down
| to 80% way quicker than normal (25-yr)
| addaon wrote:
| > The generated power will be dissipated through the
| panel as heat, AFAIK.
|
| Solar panels are not constant-power devices. In an open
| circuit, they will generate their open circuit voltage at
| nearly zero current (except minor internal leakage), and
| thus nearly zero power. In a short circuit, they will
| generate nearly zero voltage, and thus also nearly zero
| power. To get maximum power out of a solar panel requires
| maximum power-point tracking (MPPT), where the load is
| adjusted such that the product of voltage and current
| (that is, power) is optimized for the current conditions;
| while significant power can be delivered to a fixed load,
| there's no real power being generated without a load.
| CorrectHorseBat wrote:
| Where's the power going to then? Either it's heating the
| panels or it's reflected back, no?
| dzhiurgis wrote:
| Given ~20% efficiency it's almost negligible amount of
| heat.
| Dylan16807 wrote:
| The sunlight heats the panel a bit more than usual but
| there isn't really generation/dissipation going on.
|
| And since heat radiates away at temperature to the fourth
| power, the increase shouldn't be particularly much.
| addaon wrote:
| The thermal power of the sun will heat the panel, to the
| extent that it is not reflected. But no electrical power
| (or any power) is being "generated" by the panel, the
| panel is just absorbing photons like anything else with
| low albedo.
| cwalv wrote:
| Really? Couldn't you just tape a piece of cardboard over
| it?
| ragebol wrote:
| I installed an additional 12 505Wp panels by myself last
| weekend, the panels came with MC4 connectors installed
| which is pretty standard I think. Hard to get zapped by
| solar DC juice that way.
|
| BTW: installing solar panels DIY is apparently super
| easy, as I found out. I have a flat roof and used micro
| inverters, to make it easier, but I was done in less than
| a day (excluding selecting the components and layout)
| weaksauce wrote:
| if it were really a problem moving forward and diy
| becomes the norm(which i doubt is the case) it's pretty
| trivial to apply an opaque sticker or cardboard covering
| to the panel during manufacture.
| ChainOfFools wrote:
| Why can't they just be covered with blackout film until
| they're ready to be activated?
| snypher wrote:
| I just left mine half in the packaging, but I'm not Jay
| Leno.
| roughly wrote:
| > The currents and voltages involved are going to make
| that a non-starter. Do you really want random people
| messing with those?
|
| As part of our daily lives, a great many of us climb into
| a steel box powered by explosions and packing a 20 gallon
| container of flammable liquids (and increasingly several
| hundred pounds of also flammable batteries containing
| more electricity than an average family uses in a week)
| and then pilot that box at 80Mph down a strip of concrete
| packed with other large high-speed objects containing
| flammable liquids. Occasionally, we run low on flammable
| liquids in our high-speed metal box and get to refill the
| flammable liquid container ourselves at a flammable
| liquids depot, which contains upwards of 40,000 gallons
| of the flammable liquid delivered by other larger high-
| speed metal boxes which also share the same strip of
| concrete with us.
|
| So: I'd expect some product safety iteration here before
| we get to the "roll out your own solar panels", but no, I
| don't consider that a non-starter.
| szvsw wrote:
| To be fair, it didn't start that way and there are
| decades of design, legislation and safety regulations
| around all this, along with infrastructure for
| licensing/certifying capabilities, tracking and policing
| capabilities and mistakes over time, insurance, yada
| yada.
|
| It's not like that stuff springs up overnight!
| exe34 wrote:
| the safety of these steel boxes were bought with blood
| over a hundred years.
|
| and the end user doesn't just cut as much as they need
| and nail it down - the things are practically disposable
| appliances at this point.
| lompad wrote:
| But you can see fuel. You can't see currents and it's not
| trivially visible which things you can touch at all,
| which things you can touch at the same time, which
| protection to wear, how to deal with the potentially
| fatal flashing arcs, ...
|
| PV installations on roofs typically have around 10-20kW
| peak output.
|
| Let's go with 10kW. That's around 25 panels, each
| outputting 30V with something like 13A. Small
| installations are typically single-stringed, so you end
| up with a voltage of 25*30V=750V with 13A DC. That's
| pretty likely to kill you within milliseconds if you mess
| up.
|
| There's a reason that stuff tends to be handled by
| professionals. It's a ridiculous (and pointless) risk if
| you aren't well educated about it and have some
| experience.
| Dylan16807 wrote:
| So don't single string the DIY version into an
| uncontrolled danger wire. There's several ways to
| accomplish that.
| myself248 wrote:
| And you know how much mockery Oregon and New Jersey get,
| for believing gasoline is so heinously dangerous as to
| require trained dispenser operators? Meanwhile the rest
| of us just pump it into our own cars like adults.
|
| It's funny to look at electricity from the same
| perspective.
| malfist wrote:
| Homeowners work with 240v and tens of amps all the time
| across the country. Hell I wired a hot tub breaker panel
| and a car charger. Safe enough interlocks and it's a non
| issue
| lompad wrote:
| And houses are burning and people are being electrocuted
| regularly - being not only a hazard for themselves but
| also their entire neighbourhood. I certainly wouldn't
| want to live next to somebody who thinks they can handle
| their electricity installation by themselves.
| quickthrowman wrote:
| I would rather be zapped with a 240v AC current vs 240v
| DC current.
|
| AC power crosses the zero line twice per cycle while DC
| does not. AC has a lower 'let-go' threshold, but DC
| contracts your muscles and makes it harder to let go.
|
| You are correct though, if you de-energize your
| panelboard and have a deadfront cover over the line side
| conductors and lugs, working inside a panelboard (or on
| electrical wiring) is safe.
| lompad wrote:
| DC interferes with your heart's rhythm much, much less
| though, due to being constant. AC's frequency easily
| causes ventricular fibrillations even at low currents and
| voltages. AC is considered potentially lethal starting at
| 50V. For DC it's 120V, because it's significantly easier
| on your heart.
| bradknowles wrote:
| It's the amperage that kills you, not the voltage.
| 5000VAC at a 1.0 nano amps is not going to be something
| you can feel, not even as something like static
| electricity.
| Dylan16807 wrote:
| We're talking about proper sources here where the voltage
| doesn't disappear as soon as you start mildly conducting.
| So volts and amps will be proportional in this context.
|
| And the other important part is that 60Hz needs fewer
| amps than DC to be dangerous. https://www.allaboutcircuit
| s.com/uploads/articles/electricit...
| bradknowles wrote:
| I don't buy that the volts and amps will always be
| proportional. In my experience, the volts are usually
| pretty fixed, depending on the circumstances. Like 120VAC
| in most homes in the U.S., but variable amps -- 15, 20,
| 30, 50, 100, etc.... Or 240VAC in Europe and certain
| other places around the world.
|
| And if you want to talk about power lines, then the
| neighborhood medium voltage lines are going to be roughly
| the same in most places within the same jurisdictions,
| and distinct from the true high voltage lines that are
| used for long distance transmissions.
| Dylan16807 wrote:
| You are not conductive enough to get anywhere near 10% of
| the circuit's capacity. Therefore, the supply might as
| well be an infinite amp supply. You, in any particular
| situation, act as a particular ohm resistor. The amps
| that flow through you from mains voltage or big solar
| arrays will be directly proportional to the volts.
|
| If a 120V 15A supply puts 50mA through you, then a 120V
| 100A supply will also put 50mA through you.
|
| A supply that's "5000VAC at a 1.0 nano amps" really means
| that it starts at 5000 volts but super rapidly drops to
| zero volts as it conducts. A household supply is going to
| have negligible voltage drop by the time it turns deadly.
| ben_w wrote:
| I'm in Germany, our local discount retailers sell PV for
| apartment balconies as DIY systems -- "Plug and play",
| even.
|
| If Lidl can do it, why can't Walmart?
|
| https://www.lidl.de/p/vale-balkonkraftwerk-
| minipv-800-et8-l-...
| lompad wrote:
| They're limited to pretty small sizes by german law -
| they are so insignificant that they're much less
| dangerous to handle. I'm not up to date on their ROI, but
| IIR they usually were a rather bad investment and more of
| a novel toy than a serious and reliable source of
| electricity.
|
| Essentially, any notable installation fundamentally deals
| with much higher currents and voltages and as such is
| much, much more dangerous. Once a certain size is
| reached, the carrier also has to be involved and
| professional installation is mandatory, both due to the
| law and requirements by insurance companies.
|
| At least here in germany. I've been involved with
| building all kinds of PV installations in bavaria, from
| 4kwp up to 20MWp. The balkony generators aren't taken
| seriously by anybody in the industry right now, at least.
| dzhiurgis wrote:
| This is 1/10th of what my house needs (and I'm not living
| outrageously AND far closer to equator than Germany)
| ben_w wrote:
| And?
|
| They're sold for apartments, and as DIY jobs. They're
| designed to fit on a balcony just about wide enough to
| stand on, and to be installed without needing an expert.
|
| The point of the example is to show that you don't need
| an expert. It's not even trying to show a specific unit
| that suits all people, just that one thing, that you
| don't need an expert to install it.
|
| The voltages are the same regardless, because that's how
| domestic electricity works. (If you forced me to guess,
| I'd expect grid-scale PV farms to go direct to a higher
| voltage than domestic users, but I'm not an electrical
| engineer).
| forgetfreeman wrote:
| Friendly Neighborhood Handyman checking in here. Average
| Home Depot customer? Absolutely not unless there's some
| plan to quadruple suburban emergency services budgets. On
| the other hand I get pretty tired of sneaking around
| local restrictions on electrical work. Residential
| electrical work isn't exactly complex and I can't devote
| a couple years to working as someone else's laborer to
| get a cert. I'm perfectly capable of handling 100% of a
| residential solar install (including battery backup) and
| it's aggravating af to have to go find an electrician to
| bribe to get permits and inspections.
| throwaway173738 wrote:
| Around here you can buy a permit if you're a homeowner.
| You then have to set up the inspections and actually do
| all the work properly, but there are no restrictions like
| that. The inspecting agency publishes documentation about
| what to read and common pitfalls even.
| dzhiurgis wrote:
| > including battery backup
|
| Ironically batteries is what makes it feasible - I can
| dump excess into battery instead of paying 3x more for
| install so I get hooked up to grid in a certified way.
| szvsw wrote:
| Great responses, thank you! How plausible do you think it is
| that perovskite cells will see commercial adoption in the
| next 5 years? This [1] makes it seem like it is possible we
| will see the first roll out in 2025 but with significant
| uncertainty about our ability to scale up mfg after that.
|
| [1] https://spectrum.ieee.org/amp/perovskite-2667580324-26675
| 803...
| epolanski wrote:
| Can't but feel perovskite to be a fad no different than DSSCs
| before.
|
| And I say it as someone who's researched them at EPFL in
| Michael Graetzel's laboratory.
|
| I don't think the technology will ever be efficient and most
| importantly stable as needed.
| nick7376182 wrote:
| Does it degrade when hermetically sealed? I thought it was
| down to moisture and getting it in a double glass would be
| good enough
| epolanski wrote:
| Moisture heat and light all tend to degrade perovskite.
|
| Perovskite is a family a materials by the way so many of
| these issues can be sortened out.
|
| I'm overall just skeptic.
| hn_throwaway_99 wrote:
| > ... heat and light all tend to degrade perovskite.
|
| Have no knowledge in this field but if your solar panel
| material degrades in _light_ that would seem to be an
| insurmountable problem to me.
| Dylan16807 wrote:
| For "tend to", finding a design that avoids it is
| surmounting it.
|
| Or if you get it slow enough.
| naasking wrote:
| They don't have to be as efficient if they're 100x cheaper
| and lighter to boot. The stability is really the only
| issue.
| cmarschner wrote:
| At planetary scale it seems to be quite important not
| having to replace the whole fleet every few years don't
| you think? Just from a resource perspective this planet
| shouldn't drown in defunct solar panels.
| lazide wrote:
| Weight of the panels is not a significant portion of
| installation and labor costs.
|
| Square footage (aka surface area) and installation surface
| challenges are.
|
| Roof mounting is expensive. Supporting snow and wind loads is
| expensive.
|
| Reducing dead weight is only going to help a tiny percent, as
| even if they weighed literally nothing it would not
| meaningfully change the load calculations.
| szvsw wrote:
| That's in a residential/urban context. I would assume (but
| have no actual idea, just common sense) that weight matters
| at least somewhat significantly in an industrial/grid scale
| context, where shipping and labor are for MW scale systems
| rather than kW scale systems. I'm not sure how important
| the weight is here, but it seems reasonable to think that
| it _might_ be more significant than in a residential /urban
| context. Could also mean less land use, less structural
| steel, less maintenance for a system of the same capacity,
| etc.
| lazide wrote:
| It isn't. A 500 watt panel is about 71 lbs, for 27.5
| square feet. That's the typical commercial panel. A
| little smaller than a normal 4x8 sheet of plywood.
|
| Any structure designed to withstand 100 mph winds
| (typical in mild areas with no hurricanes or strong
| gusts) needs to be able to handle 25.6 psf - or 704 lbs -
| per panel just from wind load. Roughly 10x the panels
| weight.
|
| In most of the US, add on snow loads from 20-100psf or
| more. I've installed panels in areas with 150psf design
| snow loads.
|
| In the 150psf snow load area, that meant an additional
| 4125 lbs for that same 500 watt panel, each. Or about 58
| times the weight of the panel. Steep angles (30 degree or
| more) can allow reducing that, which is a good idea.
|
| So for instance in that area if not mounted _very_
| steeply, the racking needs to be able to support 71 lbs
| (panel) + 704 lbs (wind) + 4125 lbs (snow) per panel. Or
| 2.5 tons, give or take, for each 71 lb panel.
|
| The panel is about 1.5% of the weight in that scenario.
|
| And that is with no safety factor.
|
| Now the roof has already been designed to bear these
| loads of course - but not as point loads randomly through
| the roof deck. So whatever anchoring/racking needs to
| transmit the forces effectively into the roof in a way it
| can handle _without_ letting water through, and hopefully
| without making it impossible to maintain the roof either.
| And if in an area that freezes, without giving areas for
| ice to form and jack the roof /panels apart.
|
| That isn't trivial.
| szvsw wrote:
| Great response, thanks for taking the time to write out
| the numbers!
|
| What do you think about the implications for
| transportation, maintenance and land use? I have zero
| idea what the balance of those costs would be for a grid-
| scale solar farm, but ostensibly going from let's say 20%
| to 21% efficiency means you need 5% less land, weight to
| transport from factory to site, fewer panels to
| inspect/build/install, fewer to purchase, etc.
|
| I'm sure someone else has a better idea how much it would
| affect the LCOE than I do!
| lazide wrote:
| It isn't going to make something economic that previously
| wasn't. If the costs are sufficiently low (unlikely) it
| might have positive ROI in some scenarios.
|
| Generally though, solar projects are go/no-go due to
| things like cost of money and electrical sales pricing
| agreements + site specific variables like insolation,
| flatness/road access, cost of local labor, local weather
| impacts on racking costs, access to transmission, and
| bulk wholesale costs of materials.
|
| It's hard to beat flat land out in the open desert near
| major urban areas with nearby highways and transmission
| lines, for instance.
|
| What you're talking about is likely at most half a
| percent of that equation.
| szvsw wrote:
| Yep, that's what I figured! And hence my original post at
| the top of this thread, suggesting that it's easy to feel
| like we have sort of "solved" solar from a panel
| efficiency perspective and it's _everything else_ that we
| still need to improve on (grid infra, storage, etc etc),
| and additional percentage points of efficiency won't
| really mitigate the existing limiting factors.
| itsoktocry wrote:
| > _That isn't trivial._
|
| Thank you. So often when discussing solar (or EVs) we see
| bizarre extrapolations of potential install rates that
| don't account for the fact that huge swaths of the
| country (the majority of places here in Canada) have real
| challenges with installation. These are not
| insurmountable, by any means. But those challenges are
| reflected in overall cost, making some of economics less
| favourable.
| lazide wrote:
| It's always easy if we don't know/talk about the hard
| parts!
|
| In my experience, the panels themselves are at most 1/4
| of the cost of any given system, even when discounting
| labor and permitting costs.
| naasking wrote:
| What proportion of the costs are down to permitting?
| lazide wrote:
| From 50% (or more) to 5% (or less) depending on local
| jurisdiction and scale.
|
| If they want it to happen and aren't greedy? It's rarely
| a major problem. Otherwise, sky is the limit.
|
| I know of a couple sizable projects that finally got
| cancelled because the local AHJ (authority having
| jurisdiction) finally just got too greedy. In one case
| they threw on an extra couple hundred grand worth of city
| park improvements as a requirement on a couple million
| dollar (small) project. Developer ended up walking away,
| as that was the fourth time they did that.
|
| Some folks just can't help but make it lose/lose.
| hn_throwaway_99 wrote:
| But even if we reduce installation and labor costs (and as
| other comments have mentioned, weight may not be the biggest
| factor here), my understanding is that solar is already the
| cheapest energy source per kW by a pretty significant margin.
| The problem with getting it to replace carbon-based fuel
| sources is all the other issues GP comment mentioned re
| storage, grid, etc.
|
| That said, it's not like one thing is dependent on the other,
| so good to see efficiency increasing regardless.
| moffkalast wrote:
| Seems a bit counterintuitive for panels made out of lead.
| Being toxic and not very long lasting doesn't seem like the
| best combination tbh.
| tw04 wrote:
| Not just grid scale. It can be the difference of panels on your
| roof generating enough electricity to barely meet your needs to
| having so much excess you can not only supply your home needs,
| but also charge multiple EVs at home.
| maxglute wrote:
| I feel like that's a uniquely North American need. Most
| countries don't have the single family / multi car ownership
| structure. Still a real need. But implications of a country
| where large% of people can meet their own energy needs is
| interesting.
| pyrale wrote:
| The implication would likely be that the share of
| population that can't afford it won't be able to pay for
| the grid alone either.
|
| We have examples of this kind of situation in poor
| countries where the grid wasn't developed in the first
| place, and rich people use generators.
| szvsw wrote:
| This still doesn't address the duck curve aspect, or
| overnight usage. It is fundamentally impossible to use PV to
| directly power your wonderful super efficient heat pump to
| warm your home at night. You will still need batteries!
| tw04 wrote:
| And? You can buy a rack of lifepo4 batteries for less than
| $10k and it will be enough power to supply you running your
| A/C or heat the entire night.
| szvsw wrote:
| Well, my original point at the top of this thread was
| specifically about how battery mfg/infra/costs/dispatch
| (especially at grid scale) and so on seem like the
| limiting factors/primary challenges still being worked
| on, not PV efficiency, so I think we are agreeing?
| mambru wrote:
| There are heat accumulators.
| szvsw wrote:
| Yep, those are just forms of batteries though so I think
| my point stands? There is lots of cool stuff you can do
| with PV+TES without even needing true thermal batteries,
| just using smart electric hot water heaters and dispatch,
| and even cooler things if you set up a peer-to-peer
| network of them! But again, that just goes to the point
| that other challenges have overtaken solar efficiency in
| urgency (which is a great thing to reflect on!)
| Dylan16807 wrote:
| Excess panels completely address the duck curve.
| crote wrote:
| Incentivize car chargers at every workplace. Tap in with your
| personal card, and it could even be directly combined with
| your residential power bill so you're essentially charging
| using your own solar _at a distance_.
| KptMarchewa wrote:
| We've solved energy in middle of sunny, summer day. We haven't
| solved it in middle of winter night.
| okaram wrote:
| We're in the process, and may arguably already have, for the
| tropics.
|
| Get more panels, maybe some batteries.
| kragen wrote:
| in antarctica you may need nuclear or ammonia storage or
| something, but the rest of us can just use batteries
| hackerlight wrote:
| Winter being a problem really depends on location. Seasonal
| variability is much lower near the equator. Also batteries
| are becoming a solved tech. Also wind is anti correlated with
| solar, it's stronger in winter and at night. So you want
| 50-50 to minimize the need for storage.
| pier25 wrote:
| If you can reduce even 50% of the consumption from the grid
| that would be huge.
| crote wrote:
| Luckily most people are sleeping in the middle of the night,
| so electricity usage is already quite low. That's why many
| areas already have a separate discounted Night Tariff.
|
| Additionally, the winter might not have a lot of sun, but it
| usually does have quite a bit of wind. Build a combination of
| solar and wind power, and you've solved the biggest issue.
| The rest can be picked up by hydro and gas peaker plants
| (short-term), or battery storage and other new technologies
| (long-term).
| kylehotchkiss wrote:
| Solar would better be considered solved when the companies
| installing it don't require large loans, liens on your home,
| and door to door salespeople. It'd be nice if having it
| installed was more similar to having a plumber or regular
| electrician stop by
| szvsw wrote:
| I guess I meant from a technical efficiency perspective,
| rather than the social infrastructure around it. It's unclear
| to me (and frankly seems unlikely?) that few more percentage
| points will fix the very real structural issues you raised!
|
| At the same time, even if we do solve those issues, and we
| get solar panels on the roof of every home, there are still
| significant challenges to overcome as it's unlikely the
| average home can become fully energy independent (especially
| if there is electrified winter heating), and anyways, the
| energy demand from single-family residential housing is only
| one slice of the overall energy pie. In any case, it would
| certainly help if we did that!
| derriz wrote:
| That's because putting solar on rooftops makes little
| economic sense. The overhead in terms of installation cost
| was relatively insignificant when PV panels cost 20 times as
| much - as they did 15 years ago. These days, the cost is
| swamped by installation costs.
|
| These days, the only place it makes sense to put PV is flat
| on unused or unproductive land. The 95% drop in PV panels
| means that it is no longer economic to bother with mechanical
| tracking in solar farms. Integrating panels into a domestic
| roof destroys the incredible cost advantages PV has over
| alternative power sources.
| cletus wrote:
| > At the same time though, it's starting to feel to me, to some
| extent, like we have kind of solved solar?
|
| There are many metrics that affect power generation (or
| anything really). A few are:
|
| - Power generation per unit area
|
| - Power generation per unit mass
|
| - Power generation per dollar
|
| - Lifetime
|
| - Decline rate (ie does the cell get less effective over time?)
|
| - Flexibility (eg can you wrap it around a cylinder)
|
| - Minimum size
|
| - Maximum size
|
| - Cost to repair
|
| Where a given solar panel fits in the above vector space will
| change its applications. In some cases, size is paramount. In
| others, cost is paramount. Sometimes you need long-lived
| panels. A good example if solar panels for space probes. These
| need to be generate as much power for as little weight and it
| doesn't even really matter what the cost is. Also, making such
| a panel last 30 years might be irrelevant if the lifetime of
| the mission is 5-10 years.
|
| So no, I wouldn't call solar "solved".
| szvsw wrote:
| Fair points! I tried to clarify in my edit, but I was mostly
| speaking from the perspective of grid decarbonization, as
| opposed to more niche (to me) applications like space probes,
| because that is what my personal biases are towards. It seems
| like a few more percentage points of efficiency at the same
| cost/space (so ignoring something like perk pv) doesn't
| meaningfully move the needle on decarbonization efforts any
| more and that other challenges dominate (grid infra,
| batteries, etc). And I actually mean "solved" in a
| celebratory manner - it's awesome that we are at this point!
| But yes, I was totally overlooking use cases besides
| residential and grid-scale PV.
| thelastgallon wrote:
| Solar cells that can be printed like a fabric or rolls of
| paper, solar cells that can be spray painted, solar cells that
| can be grown from microbes (fastest and cheapest!) are
| technologies that will make current solar technology look
| primitive.
|
| That may take a while, but immediately though, cost-effective
| solar shingles would be so much better than wasting
| material/labor of 3 layers. Tesla roof and GAF Timberline have
| products, looks like GAF costs the same as other materials with
| tax credits. But if this can get cheaper, its a gamechanger.
| jeffbee wrote:
| How would a spray-on material have macroscopic structures
| like bus bars?
| MBCook wrote:
| Is there a known theoretical maximum efficiency for solar cells
| that we can't get past with our current approach?
|
| If they're hitting 25% are we close to that limit?
| Retric wrote:
| Depends on what you mean by current approach as many different
| methods are in use.
|
| Single junction solar cells are limited to 33.16%.
| https://en.wikipedia.org/wiki/Shockley-Queisser_limit
|
| Increase the number of junctions and that goes up. Ultimately
| with infinite layers you can't beat ~68.7% on earth and 86.8%
| when much closer to the sun.
| GeorgeTirebiter wrote:
| These efficiency limits are true for P-N junction solar
| cells. There are other solar cell types which can ultimately
| achieve higher efficiencies, but they are currently lab
| curiosities with low efficiencies.
| MBCook wrote:
| That's the kind of thing I was trying to get at with my
| "current approach" comment.
|
| Maybe solar cells based on chemical reactions or [insert
| science things here] can do far better, but right now
| semiconductors is what everyone sells.
| crazygringo wrote:
| What does closeness to the sun have to do with it?
|
| If it's a question of the intensity of the sunlight, can't
| you just focus it with a lens?
| phkahler wrote:
| TLDR they're at 25.5 percent. Didn't read but it seemed like it's
| probably a practical incremental improvement which is good.
| Sparkyte wrote:
| I can tell you I am excited... but when can we realistically
| afford solar panels with high efficiency?
|
| If a person came by my house and said, "Yo, I can do an
| installation!". Those panels are like running on a 10 year old or
| greater design and process.
| ehsankia wrote:
| Right. With something like software, if you get 1% efficiency,
| you can update most existing devices and that has a huge
| impact. With this, I feel like it would be far better to focus
| instead on lowering manufacturing costs and developing
| technology to make it easier to produce, rather than more
| efficient.
|
| Being able to deploy 50% more panels now is more important than
| being able to deploy solar panels that return 10% more
| electricity.
| Sparkyte wrote:
| Indeed if solar panel roofs were cheaper than most roofs.
| People would be able to replace them with something far more
| sustainable than someone's side project.
|
| I really like tesla's idea of solar roofs and how they
| implemented them. They need to be lightweight and cheap. Easy
| to replace.
| thinkcontext wrote:
| Tesla's solar roofs are anything but cheap, they are priced
| as super luxury.
| roughly wrote:
| Listening to some of the processes described for eking out that
| extra 1-2% efficiency, I'm curious if there's a crossover point
| where the energy required to get that last couple theoretical
| percentage points exceeds the lifetime return from the efficiency
| gain to the panel.
| szvsw wrote:
| Let's assume a system outputs 2 MWh annually at 24%. Let's bump
| up to 25.5% efficiency, and we get 2.125 MWh. Let's assume a 30
| year lifespan. This gives us an extra 3.75 MWh total over the
| lifetime. Let's round down to 3 MWh to very conservatively
| account for performance degradation.
|
| That would be the raw energy budget. It seems unlikely to me
| that these processes would require more than 3 MWh additional
| energy for a system of this size compared to the baseline 24%
| system, but that's just on vibes!
|
| At the same time, it's probably better to view it in terms of
| carbon, in which case the situation changes a little bit. You
| would need to know how carbon intensive the source power
| production is for the manufacturing process, and additionally
| how the grid decarbonizes: if the grid decarbonizes
| substantially due to (eg) massive wind scale up and deep
| geothermal breakthroughs, then the efficiency gains from PV
| aren't as valuable in the future from a carbon perspective as
| they are in the year 2025.
| szundi wrote:
| Isn't installation costs like frames, transportation and labor
| makes it irrelevant now?
| szvsw wrote:
| Lots of discussion of this in other comments in this thread,
| but at least theoretically, for a system of the same size, a
| change from 20 to 25% efficiency would reduce: the number of
| frames to manufacture, the weight of the transported goods, the
| number of panels needed to be installed, and the space needed
| all of which do plausibly reduce the total cost and time to
| deploy, no?
|
| That change is itself a 25% performance improvement (over the
| 20% baseline), meaning you need significantly less space and
| potentially weight/labor to install. Obviously we aren't making
| that jump all at once.
| dv_dt wrote:
| Perovskite cells have not been demonstrated to last nearly as
| long as silicon cells. If you trade cheaper, conversion efficient
| cells, but they last 1/5 the age, the system cost is much higher
| because you'll have to re-pay for replacement / reinstallation
| costs much more frequently.
| boringg wrote:
| While I can speak to the veracity of your statement. If true it
| would feel that this is industry finding a way to create a long
| term subscription fee to buying their product?
|
| It would be the worst outcome possible - the beauty of solar is
| that it lasts for 40-50 years while only having to replace
| inverter / maintain the system.
|
| Thankfully commercial grade and investors wouldn't bank on
| that.
| dv_dt wrote:
| It's not actually clear to me if this article is talking
| about Perksovite cells at all, or a different set
| manufacturing techniques improving on current common
| techniques for the current state of practice. I think should
| have hung my comment off of some of the other threads on this
| that were in a side discussion of Perk cells.
| bradknowles wrote:
| Things that are exposed to the weather frequently need to be
| replaced more often than every 40-50 years. Like roofs. And
| cables. And anything that is an external attachment to the
| structure.
|
| You might not have to replace the solar panels themselves
| except on a 40-50 year basis, but if you've had to replace
| everything else that's been exposed on a more frequent basis,
| I would have to ask Mr. Theseus how much of that solar system
| is really the same, and how many of those costs would have to
| be re-incurred over that longer period of time due to the
| shorter life span of the other products.
| secondcoming wrote:
| How often are you replacing your roof!?
| bradknowles wrote:
| I know our roof is in pretty bad shape, and will need to
| be replaced in five to ten years. The house was built in
| the mid-80s, we bought it in 2008, and I know it's had at
| least one or two roof replacements in that time.
|
| Most roofs aren't even built to code, which is supposed
| to be the floor below which building quality cannot go.
| Instead, they build to whatever they can get away with,
| and in many places, that is much lower than code because
| the building inspectors are busy and don't check, or
| they're careless, or they get bribed off.
|
| In most single family homes, the more you learn about the
| construction of your specific house and what standards
| they were supposed to build to but didn't, the more
| horrified you will become.
|
| Like the builder leaving out a $2.00 piece of flashing
| because either they didn't care, or they thought it was
| too expensive. Of course, the result of that $2.00
| flashing not being there is tens of thousands of dollars
| of damage that occurs to your house over the next decade-
| plus, for which your insurance company will pay precisely
| $0.00, since it's not the result of a single catastrophic
| event.
| shellfishgene wrote:
| The first company, just started selling perovskite solar cells
| with 10 years warranty on stable energy production and 25 years
| warranty on working without drastic loss in function, so there
| seems to be improvement.
|
| https://www.pv-magazine.com/2024/06/13/commercial-perovskite...
| dv_dt wrote:
| The article mentions 25 year linear degradation warranty,
| what would be the remaining capacity after 25 years? Because
| the article doesn't mention it, I assume it's worse than
| silicon. For silicon it is typically 80% after 25% with most
| panels commonly exceeding that 80% mark.
| rvba wrote:
| The PhD here talks about 1% gains, meanwhile some random website,
| windows process or chrome itself takes a lot of power - and it
| seems nobody cares. Yet it adds up too. Not only via ecology,
| also often poor customer experience.
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