[HN Gopher] Satellite powered estimation of global solar potential
___________________________________________________________________
Satellite powered estimation of global solar potential
Author : jonbaer
Score : 256 points
Date : 2024-12-19 20:44 UTC (1 days ago)
(HTM) web link (research.google)
(TXT) w3m dump (research.google)
| HocusLocus wrote:
| "We lose a little on each transaction, but make up for it in
| volume."
| janitorHenry wrote:
| Builders: optimize energy capture, put roof planes directed south
| (in northern hemisphere).
| elric wrote:
| That's terrible advice unless it's tied to local energy
| storage.
|
| When every roof and every solar panel is angled the same way, a
| sudden cloud (or a sudden lack of clouds) can cause huge
| fluctuations in power output. Diversity is protective.
| cjbgkagh wrote:
| Unless there is something I'm missing, the sun still shines
| from the same direction regardless of the cloud coverage so
| I'm not sure how having panels pointing in other directions
| could improve the matter. Perhaps there is a case for
| optimizing panel area for different times of day but since
| panels are so relatively cheap it seems the advice is just to
| get more panels than spend much time worrying about such
| things.
| jcgrillo wrote:
| Are you signing up to point your panels north and take a 30%
| efficiency hit? Or east/west for a 15% penalty? People point
| them south because it's the most efficient fixed orientation
| north of the equator. A more efficient solution is to use a
| tracker which keeps them pointing directly at the sun as it
| traverses the sky.
| elric wrote:
| Not every roof allows for perfect southward angling
| (obviously).
|
| And I'm obviously not saying that you should point panels
| north either. I'm disputing the parent commenter's claim
| that it would be beneficial to have all panels aimed
| directly due south. Because that way you get one strong
| peak at noon, which is the time of day when solar energy is
| most abundant but also least used.
| toast0 wrote:
| Pointing west is a reasonable option in California.
| Pointing west reduces production, but also shifts it later
| in the day, and addresses some of the duck curve.
| lostlogin wrote:
| It might be that south gives you the most electricity (I'm
| southern hemisphere so north for me), but if you're after
| power for yourself, early am and late PM energy generation
| is very helpful.
|
| A battery helps negate this issue but not entirely.
| PaulDavisThe1st wrote:
| The potential for mechanical failures in trackers makes
| them quite unpopular now (unlike in the 70s when they first
| started to appear, and seemed like an obvious win).
|
| You're better off just adding however many extra fixed
| panels you need to make up for the lack of tracking (and
| its normally not very many).
| dzhiurgis wrote:
| This problem has been know for well over a decade...
| szvsw wrote:
| There's not always a lot of freedom to control roof angles like
| that - it might eg be directly determined by the orientation of
| the street - and even if there is, it might come into conflict
| with other thermal considerations. For instance, perhaps
| orienting the building such that the roof midline is E/W and
| the surface is due south results in more windows pointed due
| south, which in turn drives much more solar gain on the
| interior and greater cooling loads as a result - maybe the
| increased solar output outweighs those gains, maybe it doesn't.
| You have to run some thermal sims to check. On the other hand,
| you will have more solar gains in the winter, which will
| decrease your heating demand.
|
| So it's not universally applicable - but it is absolutely true
| that it will increase solar output!
| PaulDavisThe1st wrote:
| > more windows pointed due south, which in turn drives much
| more solar gain on the interior and greater cooling loads as
| a result
|
| C'mon ... people figured this out in 70s ... and centuries
| before that in various parts of the world.
|
| You put a shade above the window the excludes direct summer
| sun, but allows direct winter sun to enter the window. The
| angle and extent of the shade depends on where you are in the
| world.
|
| On my old adobe in New Mexico, a roof at about 30 degrees
| with about an 18" overhang prevents all direct summer sun
| from entering our south facing windows, but provides 6-10F of
| additional ambient temperature during the winter from direct
| sunlight.
| szvsw wrote:
| Oh I'm totally with you! There is a long and storied
| history of passive design strategies, and exterior shading
| is one of the oldest ones out there!
|
| But what I stated is plainly true, and many people simply
| don't want exterior shades (or just don't think about it).
|
| The point I was trying to make was just that there are
| thermal implications to the orientation, and you should
| think those through (using thermal simulations can help
| detect these issues) and come up with appropriate
| strategies (thermal simulations can help validate them).
| Maybe you don't want shades, but you would be okay with
| emissivity coatings for your windows. Or maybe you just
| want to position windows on both sides of the home with
| continuous air volumes connecting them to promote natural
| ventilation. Maybe you can take advantage of thermal mass.
| The list goes on...
| PaulDavisThe1st wrote:
| I was not describing exterior shading. The terminology is
| hard. I was describing overhangs that create shade during
| the summer.
| szvsw wrote:
| Overhangs are considered exterior shading in the
| industry/practice/academia. Any obstruction that prevents
| solar gains by blocking radiation from entering the
| window falls within the general category of external
| shading, whether that's a fancy high tech actuated
| shading system, a grille, a simple awning, a structural
| overhang, vertical fins, etc.
| PaulDavisThe1st wrote:
| A structural overhand is viewed by _homeowners_ as
| something utterly different from everything else you 've
| mentioned there.
| edent wrote:
| That isn't quite true.
|
| Electricity use is more common in the evening, so west facing
| panels do really well because they offset demand.
|
| We have an East/West split on our panels and they're excellent
| for providing instantly useful electricity as opposed to stored
| electricity.
| ben_w wrote:
| Nice to see, I hope it helps people get more cheap energy.
|
| All I have are nits to pick:
|
| > 10.7k TWh globally
|
| This brings back memories of the time I almost shortened
| "thousand kilometres" to "kkm".
|
| Also, and this is not a criticism of Google, the IEA link on that
| text looks suspiciously like the IEA is still forecasting linear
| deployment of PV between 2025 and 2035, despite at least a decade
| of people pointing at it being historically exponential and
| asking why they don't assume the exponent will continue -- I'm
| expecting about double their number for PV by 2035, if trends
| continue.
| jjcm wrote:
| > 10.7k TWh globally
|
| Agree I hate this, but at the same time I don't know if I would
| have groked it correctly on first read if it had listed
| "10.7Pwh globally". We simply aren't exposed to numbers at that
| scale on a regular basis.
|
| Not sure what the correct solution is here.
| geepytee wrote:
| The correct solution is 10.7Pwh. We are often exposed to
| 'Peta' when dealing with data.
|
| https://en.wikipedia.org/wiki/Metric_prefix
| jeffbee wrote:
| EIA Electricity Monthly gives data in certain tables in terms
| of either million kWh or "thousand megawatthours" which isn't
| even English. Let's just use J.
| psychoslave wrote:
| I was reading
| https://en.wikipedia.org/wiki/International_System_of_Units
| and a few related the other day for fun and pleasing moment,
| and one thing I retained from that is that "The kilogram is
| the only coherent SI unit whose name and symbol include a
| prefix." Also that the standard explicitly forbid redundant
| use of prefixes like kilo-kilo-.
|
| I guess that if you want to stick to TWh you can use
|
| - 10700
|
| - 10,700
|
| - 10.7x103
|
| - 1.07x104
|
| - 10.7e3
|
| - 1.07e4
|
| - 29E816
| Veserv wrote:
| SI prefix words are just kind of silly. We should just use
| the exponent as a number instead of having a different word
| for every 3 zeros. 10.7 E15 Wh or something similar.
|
| Scales to everything, you do not need to know any mapping,
| and directly supports mathematical manipulation.
|
| We should also do the same for large number words in general.
| No thousand, million, billion, etc. E3, E6, E9, etc. Now you
| can count and represent any meaningful number without needing
| to memorize a dictionary of words and they would precisely
| match the unit scale "words".
| ant6n wrote:
| You mean 1.07E16
| vermilingua wrote:
| It's pretty common in some contexts to only use Es for
| powers of 1000, so 100,000,000 is 100e6 rather than 1e8.
| SAI_Peregrinus wrote:
| That's commonly called engineering notation.
| rabidrat wrote:
| I agree! I use ^3 etc for the notation: https://saul.pw/mag
| mjan22640 wrote:
| Joules is the solution to both the problems (the second is
| that Wh for energy is as silly as speed hours for distance)
| XorNot wrote:
| Watt-hours is a perfectly pragmatic unit. Measure
| instantaneous power and multiply by a common human unit of
| time. It's easy to compare.
| ben_w wrote:
| Part of me is tempted to suggest kilograms as a unit of
| energy.
|
| 428.6 kg relativistic mass-energy equivalent: https://www
| .wolframalpha.com/input?i=10.7PWh%2F%28c%5E2%29
|
| But then, I am a silly person.
| sbierwagen wrote:
| >(the second is that Wh for energy is as silly as speed
| hours for distance)
|
| This would be a devastating own if a single Joule wasn't
| exactly equal to a Watt-second.
| sneak wrote:
| Well, given that the intent is to communicate, using GWh is
| probably ideal. 10.7 million GWh is probably the easiest to
| understand and compare, given that GWh is probably the most
| commonly used unit for this purpose.
| PaulDavisThe1st wrote:
| We should be. Why? Because reasonable estimates of the amount
| of extra energy contained within the atmosphere due to
| anthropogenic effects are in the single digit petawatt range.
| It's a number everyone should be carrying in their heads.
|
| Put a different way: the total annual harvestable solar yield
| is within an order of magnitude of the energy we've caused to
| accumulate inside the atmospheric boundary. Think about that,
| for a second or two.
| rcMgD2BwE72F wrote:
| >despite at least a decade of people pointing at it being
| historically exponential and asking they don't assume the
| exponent will continue.
|
| So crazy and true. Sources:
|
| https://www.economist.com/interactive/essay/2024/06/20/solar...
|
| https://www.exponentialview.co/p/the-forecasters-gap
|
| 7 years ago (!): https://xwpxpfefwalgifkr.quora.com/A-modest-
| proposal-to-the-...
| Retric wrote:
| Both linear and using the current exponent are likely to be
| wildly off.
|
| If you assume it's ~26% annual growth now, and drops by 2% per
| year so 24% next year then in 10 years you'll see 4.25x last
| years installs and the cumulative initiation over the next
| decade is 2.8x a linear estimate.
|
| IMO that's probably a reasonable ballpark, though capacity
| factors are an open question as they could fall dramatically or
| maintain fairly steady depending on how much grid storage shows
| up.
| akira2501 wrote:
| > This brings back memories of the time I almost shortened
| "thousand kilometres" to "kkm".
|
| SI is such a senseless system. Unit prefixes were not a good
| idea. Did you move the decimal point or just switch to "Mm?"
| ben_w wrote:
| In that specific case, I chose megameters.
| sneak wrote:
| At which point even metric-users who think in km are
| confused.
|
| Certain things are measured in certain units, prefix
| included.
|
| This would be like writing interstellar distances in km
| instead of light years or parsecs.
| PittleyDunkin wrote:
| > This brings back memories of the time I almost shortened
| "thousand kilometres" to "kkm".
|
| For the uninitiated, what's confusing about this? It seems to
| communicate the intended meaning accurately. Is there some
| ambiguity here I missed?
| elliottkember wrote:
| I think it's that a thousand terawatts is equivalent to one
| petawat. So this is 10.7PWh.
| PittleyDunkin wrote:
| Ah so the complaint is of moving the last order of
| magnitude onto the quantity rather than the unit. I can't
| imagine this affects readability that much (although I can
| understand why you'd want to enforce consistency in an
| academic context).
|
| Sometimes it's useful to distinguish these, though. And
| after many do have the inexplicable "MM" suffix (ie s
| thousand-thousand) to suffer through which seems much
| worse.
| jeffbee wrote:
| The image processing described is very cool, but I have questions
| about the application. Google started doing these solar potential
| estimates about 10 years ago, so let's imagine that they have
| been developing the capability since about 2010 or so. In that
| time the cost of PV has fallen by an order of magnitude. Hasn't
| that settled the question of where PV should be installed? I
| thought the answer is now "yes" everywhere.
| josh-sematic wrote:
| Even assuming 100% solar rooftop coverage is the goal, given
| limited capacity of raw materials, labor, infrastructure would
| still necessitate prioritization of when to allocate those
| things to which places.
| jeffbee wrote:
| But the audience isn't an omnipotent controller of PV panel
| allocation, it's emergent market participants. Presumably,
| the market emerges more plentifully in those sunnier places.
| It's hard to imagine the place where this data is useful to
| local construction firms who were previously not well-
| informed (potentially by just walking around with their eyes
| open).
| mbreese wrote:
| Maybe it's useful when trying to justify solar adoption. If
| you have control over some level of panel allocation, you
| could use something like this to explore where you'd want
| to put panels first -- answering the question of where are
| you going to make the best economic case for solar panels.
|
| Then, once the top places are addressed, you can move onto
| the second tier of locations, then the third, etc...
|
| This could be helpful if you're in gov't and have some
| control over a pilot neighborhood project. Or a developer
| that wants to include solar on some homes/businesses and
| wants to know where it makes the most sense.
|
| You're right that this probably isn't too much better than
| qualitative reasoning about how sunny certain places are,
| but this is quantitative, so you can have a little more
| confidence in your qualitative assessment.
| josh-sematic wrote:
| There are several allocation opportunities I could think
| of. You're a local government considering some subsidies
| for rooftop solar initiatives. How much bang for your buck
| will you get? You're a regional grid operator and have some
| estimates for rooftop solar adoption. How do you translate
| that into plans for future grid capacity needs? You're a
| rooftop solar installation company. What neighborhoods do
| you send your mailers to?
| akira2501 wrote:
| Perhaps those three different groups should just
| coordinate together, rather than individually using this
| data, and arriving at three different and possibly
| interfering conclusions.
|
| Aside from that grid operators buy power from producers.
| They don't plan future capacity more than 72 hours in
| advance. If you're a producer with expensive power you
| won't sell much. If you're a producer with cheap power
| you will sell a lot. It's already a functioning market.
| Solar is a very small part of it.
| wongarsu wrote:
| A lot of new homes are still constructed without solar. Either
| market participants are sleeping on easy money or the answer
| isn't a simple "yes, everywhere".
|
| The cost of panels has fallen a lot, but the cost of mounting
| hardware and installation is still pretty high in the US.
| jeffbee wrote:
| That's exactly my point. This isn't telling you anything
| about the controlling variables: labor, G&A, taxes.
| xnx wrote:
| This is a very impressive refinement of their existing tool, but
| is this type of advanced calculation of roof-pitch (etc.) still
| relevant?
|
| Haven't we more or less concluded that a million piecemeal
| rooftop installations of solar are about the worst way to do it?
| More complicated and expensive to permit and install, less
| efficient operation, difficult to repair, difficult to insure,
| difficult to upgrade, inefficient to integrate into grid, etc.
| dvh wrote:
| I'll take 3kW on my rooftop over 5kW in billionaire's company.
| szvsw wrote:
| One advantage of distributed solar is that it can at least come
| online right away and when installed with a battery, can get a
| home pretty close to being fully self-sufficient (depending on
| the climate/heating system), whereas the generally much more
| efficient solar pv power facilities have to contend with
| backlogs in connecting to the grid, insufficient grid capacity,
| etc.
|
| But yes, distributed solar will not be the general solution to
| decarbonizing our energy systems as a whole. Does serve a
| meaningful role though and there is no reason to not do both.
| CorrectHorseBat wrote:
| Insufficient grid capacity can also be local, there are many
| cases of inverters turning off because of too high grid
| voltage in the Netherlands
| throwaway346434 wrote:
| Or to put it another way: available with a rate of return that
| makes it sensible for average middle class home owners to say
| yes to, to the point dirty power sources are having to shut
| down in some markets (or fiercely lobby through the political
| system to be propped up).
|
| One such example:
| https://www.theguardian.com/environment/article/2024/sep/08/...
|
| Perfect is the enemy of good
| tejtm wrote:
| I thought we may have concluded that shareholder efficient
| centralized single point of failure systems are the least
| robust providers of basic human needs in the face of natural
| levels of uncertainty.
| yen223 wrote:
| With rooftop solar there's a path towards mass deployment that
| other alternative electricity generation solutions currently
| lack. Rooftop solar for residential houses doesn't require
| permits or planning, and can be done by individuals within a
| reasonable budget, unlike solar farms or rooftop nuclear.
| PaulDavisThe1st wrote:
| > Rooftop solar for residential houses doesn't require
| permits or planning
|
| Either you're assuming residential battery storage systems
| replacing the grid, or your ignoring the connecting rooftop
| solar to the grid requires permits and planning (the grid may
| not be able to handle it).
| pjc50 wrote:
| Depends on your jurisdiction. UK home solar under 4kW
| doesn't require permission.
| akira2501 wrote:
| > More complicated and expensive
|
| More durable for individuals in the face of large scale
| failures. You're paying for something real there.
| ijustlovemath wrote:
| As someone who recently lost power and water for weeks post
| Helene, do not discount the power of distributed grids.
| Distributed core infrastructure will make for much better
| climate resilience. Don't miss this in your efficiency
| calculations.
| XorNot wrote:
| Grid connected solar goes down when the grid is out though.
| You need specific inverters to retain power.
|
| You also just have issues like the low chance of having clear
| skies after a hurricane or a bushfire.
|
| For disaster situation power, a diesel generator is still the
| cheapest and most reliable option.
| ijustlovemath wrote:
| Sure, but that's why my emphasis was on distributed
| _grids_. Interlinking local capacity / having one or two
| neighbors with fully fledged systems is way better than
| going weeks charging stuff in your car. When you're without
| power for weeks, you'll probably have enough sun for more
| than enough days to get yourself sorted. Hurricanes also
| tend to sweep up any other systems in the region, so once
| they disperse, it's pretty clear skies. Anecdotally, we
| didn't get any rain for months after Helene dissipated.
|
| Also, diesel and gas were pretty much inaccessible for the
| first 5 days of the disaster, so unless you have a
| stockpile that's been treated for longevity, you might not
| even be able to run your whole home generator for long.
| NavinF wrote:
| > Interlinking local capacity
|
| Is this a thing IRL? Every system I've looked at stops
| feeding the grid as soon as the grid goes down
| wongarsu wrote:
| They have to. Feeding your own home needs some setup but
| is fine. But electricity companies require you to
| disconnect generating capacity from the grid when the
| grid is down to make it easier to effect repairs.
|
| But that's more a policy decision than a technical
| restriction. We could change it so power can flow on both
| sides of a fault instead of only the "upstream" grid
| side.
| xbmcuser wrote:
| With battery systems getting so cheap maybe community
| batteries will become a thing where a neighborhood
| exports it's solar too and is it's own small grid.
| PaulDavisThe1st wrote:
| that would mean either:
|
| a) government mandates that turn over existing grid
| infrastructure to such a project, because the existing
| grid infrastructure is almost all privately owned
|
| OR
|
| b) building new infrastructure to create an isolatable
| local grid
|
| Neither of these seem particularly likely to me.
| XorNot wrote:
| I mean it isn't though: it's defense in depth - policy is
| you must disconnect. Line workers will drive a ground
| stake in on both sides anyway, but if you don't
| disconnect then they'll just short your inverter to
| ground.
| malfist wrote:
| There's a program involving F150 lighting trucks out in
| CA that pay you to grid tie them, that way a couple of
| them in your neighborhood can power the neighborhood for
| a day or so if wildfires take out the local grid
| PaulDavisThe1st wrote:
| Anything grid tied is generally required to have
| phenomenally reliable shutdown if the grid goes down OR
| proven (and very expensive) automated switching that
| disconnects it from the grid if the grid goes down.
|
| This is so those F150s are not backfeeding the wires
| while a repair crew is trying to fix it.
|
| Ergo, if the local grid is "taken out", those F150s
| cannot be "on the local grid".
| malfist wrote:
| I'm sure you know what you're talking about, but Duke
| energy is running the program, and they wouldn't be
| paying people to grid tie their EV for disruptions unless
| they could use it: https://news.duke-
| energy.com/releases/illuminating-possibili...
|
| The lightning extended range has a 135 kwh battery and
| can backfeed 90A@240V. That's a heck of a lot of power.
| NavinF wrote:
| Article says "customers will allow their EVs to feed
| energy back to the grid - helping to balance it during
| peak demand". It doesn't say anything about what happens
| when the grid goes down during disasters
| ijustlovemath wrote:
| Referring more to microgrids here; think city
| block/neighborhood level independent grids
| NavinF wrote:
| Ah I see. AFAIK selling electricity is highly regulated
| in most states so I can't imagine microgrids taking off
| in the US. It would be cool though
| bruce511 wrote:
| >> Grid connected solar goes down when the grid is out
| though. You need specific inverters to retain power.
|
| Yes, and sort of.
|
| Inverters will prevent power flowing to the grid if the
| grid is off. However most inverters will continue to supply
| power into the house while the grid is off.
|
| There are various factors in play here, and you need to do
| proper homework, but certainly a fraction of the house can
| be powered, if not all of it.
|
| I'm not sure if this is "special" inverter or not. Every
| one I researched had the same functionality.
| bagels wrote:
| Most solar installations without batteries do not
| function without grid power present. Sure, some could,
| but most do not.
| p1mrx wrote:
| > a diesel generator is still the cheapest and most
| reliable option.
|
| The shelf life of diesel is about a year; the shelf life of
| propane is effectively unlimited.
| outside2344 wrote:
| Not if you have a battery system attached
| macintux wrote:
| I'm amazed at the amount of opposition to centralized solar
| generation. I assume there's a fair bit of fossil fuel industry
| astroturfing involved.
| dzhiurgis wrote:
| It all hinges on how much your infrastructure costs. At the
| moment something like 1/3rd of your retail cost if delivery.
| At some point it's 15x cheaper to have 1kW home feed in +
| battery vs 15kW feed in.
| macintux wrote:
| Responded to a sibling comment: I'm referring to people who
| oppose industrial solar installations for some reason.
| bruce511 wrote:
| There's the perception that it's an "either" question. When
| in reality its both.
|
| Home solar is a big win, and if nothing else allows capital
| to be sourced from a million home owners.
|
| Centralized solar is a big win, generating grid power Erich
| is obviously important.
|
| It's not a question of either, it's a question of both.
| macintux wrote:
| I should have made it clear: I'm referring to people who
| are adamantly opposed to large solar installations,
| apparently because it's a threat to agriculture? It's very
| odd, but I see yard signs and bumper stickers everywhere in
| rural Indiana.
| throwaway2037 wrote:
| Do you think some farms in rural Indiana will make more
| money by converting to a solar power park? I could
| imagine it, and I could imagine that some people would
| feel threatened by this change.
| macintux wrote:
| Sure, but follow the money: unsurprisingly it's the usual
| big money bad actors who are funding opposition.
|
| https://energyandpolicy.org/fossil-fuel-funding-
| opposition-r...
| WillAdams wrote:
| Yes, but one back-of-the-envelope calculation (it was a Python
| program someone wrote up as part of a comment on Slashdot as I
| recall) demonstrated that if all of New York's roofs were
| covered in solar panels there would be enough energy to run the
| city....
| Scoundreller wrote:
| Enough energy or enough electricity?
| WillAdams wrote:
| Good point. It feels right that the calculation ignored
| losses --- but if I recall, it did include panel efficiency
| and that has gotten much better, so maybe it would work
| now?
| xattt wrote:
| Why not both?
| Glyptodon wrote:
| At a certain point shouldn't things get good enough you don't
| really need a traditional power grid?
| wongarsu wrote:
| Residential power demands are highest in the morning and in
| the evening. That's when people shower, cook, and are
| generally around using power. Solar peaks at noon.
|
| Maybe when battery prices come down even more. But the cost
| of grid-level storage are also falling, and wind pretty much
| only works at grid scale. Grids have to change but won't
| become obsolete anytime soon.
| PaulDavisThe1st wrote:
| That usage pattern will be quite different in places with
| cold winters when most people there are using electric-
| powered heat pumps (which is "the plan").
| benlivengood wrote:
| Grids are pretty much the best solution available because any
| kind of good/service that can be transported at close to
| light-speed benefits tremendously from ubiquitous
| connectivity.
|
| Smarter grids are an even better solution; batteries backing
| local high-variance demand combined with rapidly negotiated
| requests for transmission power to meet expected future
| demand (and then stored in the batteries) reduces
| (electrical) inefficiency to a minimum.
| yongjik wrote:
| Sounds like a rare case of America's ubiquitous suburbs working
| out for the environment. Everyone has a "roof" that gets
| sunlight most of the day, so rooftop solar, while being less
| efficient, is still a viable candidate.
|
| (Although, if you factor out all the extra driving needed for
| the suburban life, it would likely still come out negative
| compared to a proper city.)
| szvsw wrote:
| Yeah, don't over look the fact that the thermal demand from
| space conditioning homes is way higher on a per capita basis
| in a suburban context compared to an urban context with
| multi-family housing/apartments etc. There's just way more
| air volume to condition per person, generally more
| inefficient systems, etc.
| yongjik wrote:
| Even for the same amount of living space, apartments are
| way more efficient. A typical apartment unit is surrounded
| by other units up/down/left/right, so only two sides are
| exposed to outside air. A single house is exposed on five
| sides.
| nwiswell wrote:
| > A single house is exposed on five sides.
|
| Six. The most heat escapes through the roof, but thermal
| loss through the floor is generally about 10-15% of the
| total.
| szvsw wrote:
| Yeah we refer to this as the heat loss form factor of the
| building, which is determined largely by the surface area
| to volume ratio (so you have a square-cube relationship
| at work) as well as the the number of floors in
| conjunction with the roof area. With more floors, the
| heat transfer through the roof (which can be substantial,
| as mentioned by a sibling comment) is less significant
| for the same roof area (after normalizing for the gross
| floor area).
|
| Same goes for the slab/foundations (which can also have
| substantial thermal transfer in many contexts).
| yourMadness wrote:
| There are enough panels available to do both and there is no
| overlap in financing for both. So just do every installation
| that is economically viable, they don't compete for money or
| panels.
| rgmerk wrote:
| Australia manages to install rooftop solar at well under half
| the cost the USA does (most of that is soft costs) and
| integrate large amounts of it into the grid.
|
| As of lunchtime today, nearly 50% of all electrical generation
| on the national grid was rooftop solar (and another ~10% was
| utility-scale solar).
|
| Rooftop solar works just fine if utilities don't actively try
| and obstruct its use.
| throwaway2037 wrote:
| > As of lunchtime today, nearly 50% of all electrical
| generation on the national grid was rooftop solar
|
| Wow, this is incredible. Can you share your source? I would
| like to learn more!
| guerby wrote:
| https://aemo.com.au/energy-systems/electricity/national-
| elec...
| ltbarcly3 wrote:
| That's a great achievement, but could be stated in a more
| clear way.
|
| Not 'As of lunchtime' but 'At precisely lunch time'. An hour
| later it wasn't 50% anymore, and it won't be 50% except at
| noon for a long time yet. As of the moment I am posting this,
| solar is 0% and coal is 80%. If Australia cares about global
| warming they should build nuclear plants and stop generating
| 70% of their overall power from coal.
|
| It's still remarkable how much solar is growing and I hope
| it's 100% 24/7 soon!
| rgmerk wrote:
| Sorry. The point of my post was to respond to the claim
| that you can't effectively integrate meaningful amounts of
| rooftop solar into an electricity grid in a cost-effective
| manner when the evidence from Australia is that you can and
| we have.
|
| If I'd looked the example when South Australia's
| interconnector with the rest of the NEM went out, they had
| periods with the instantaneous penetration of rooftop solar
| was over 90%. AEMO, the body that manages the Australian
| electricity grid, are aiming to be able to support a 100%
| instantaneous renewable mix on the NEM within the next year
| or two.
|
| As for Australia's overall electricity mix, that is
| _rapidly_ changing (and the numbers get a bit distorted by
| the amount of self-consumption of rooftop solar). We 're at
| 40% renewables overall now, and while it may not hit the
| government's 82% target by 2030 we will almost certainly
| reach 70% or so by 2030 and I'd think 90% by 2035 is very
| doable. The last 10% is harder, but there are enough
| options (gas with CCS, green hydrogen, biofuels, long-term
| energy storage of other kinds) that I reckon we can get
| there. We are in the fortunate position of not having solar
| completely go away for months in the winter.
|
| As for nuclear, it's never, ever going to happen in
| Australia (despite the claims of the conservative side of
| Australian politics). Even if Australia could build nuclear
| power as efficiently as South Korea - an extremely big ask,
| given we have the same challenges at building large
| infrastructure as the rest of the English-speaking world -
| it still doesn't make economic sense.
| bruce511 wrote:
| >> Haven't we more or less concluded that a million piecemeal
| rooftop installations of solar are about the worst way to do
| it?
|
| It really depends on what you mean by 'worst'. In terms of
| land-usage it's the best. In terms of speed-of-deployment it's
| the best. In terms of distributing capital spend its the best.
|
| In terms of capital return, that will vary from one house to
| the next because it depends on location, energy consumed (and
| when), elec prices in your region, grid stability, and so on.
| rsanek wrote:
| what do you mean by "distributing capital spend"? as in the
| money to pay for the installations is not concentrated to
| large utilities? why is that desirable?
| adrianN wrote:
| Sometimes it's easier to find a thousand people with a
| thousand dollars than one guy with a million dollars.
| opo wrote:
| >...Haven't we more or less concluded that a million piecemeal
| rooftop installations of solar are about the worst way to do
| it?
|
| The data shows that you are correct. Utility grid solar
| provides low cost power and consumer rooftop solar does not and
| will not. The rooftop solar price is usually hidden because no
| power source has been as subsidized as rooftop solar. Besides
| direct subsidies, wealthier home owners have often been paid
| the retail rate for the electricity they sell to the grid which
| causes higher electricity bills for those who can't afford to
| put panels on their roof - sort of a reverse Robinhood scheme.
|
| As the statista.com report says:
|
| >...Rooftop solar photovoltaic installations on residential
| buildings and nuclear power have the highest unsubsidized
| levelized costs of energy generation in the United States. If
| not for federal and state subsidies, rooftop solar PV would
| come with a price tag between 117 and 282 U.S. dollars per
| megawatt hour.
|
| https://www.statista.com/statistics/493797/estimated-leveliz...
|
| Looks like that report is a year old, but I doubt the
| installation costs have really gone down much since then.
| (Panel prices come down, but labor costs, etc. don't.)
| ZeroGravitas wrote:
| Yes it's relevant and no we didn't all agree it was a bad idea.
|
| It generates power at roughly the cost of nuclear. It's
| distributed and resilient. It works around sluggish government
| and/or corporate monopolies. It reduces transmission
| requirements. It enables and encourages electrification and
| time-shifting of load. Adding it at build time can be cheaper
| than tiling.
|
| It's generally a good thing and we'll see even more if it as
| the tech progresses and gets cheaper.
| rgmerk wrote:
| Hate to sound like a broken record but the barrier isn't the
| technology, the barrier in the USA is permitting and soft
| costs.
| jillesvangurp wrote:
| Depends on your cost of electricity. In most places, a solar
| setup pays for itself long before the warranty runs out max
| 5-10 years typically (depending on a lot of factors). Even in
| the US which has a lot of extra cost related to people making
| things needlessly complicated and costly, lots of people are
| installing solar and earning their money back.
|
| I can actually get balcony solar here in Germany for about 240
| euros. Here's how that works:
|
| - I buy a kit on Amazon. I found several nice ones. This one is
| rated for 850w and includes cables, inverters and other bits
| and bobs needed.
|
| - I zip tie the panels to my balcony
|
| - And I plug in the equipment and connect it to a wall socket
|
| The idea is that this would offload some of the power used by
| e.g. my fridge. Not the same as a rooftop setup obviously and
| in my case quite pointless since I don't have a lot of sun on
| my balcony.
|
| But I might actually qualify for a rebate if I do this and get
| all or most my money back. The government is sponsoring this
| and landlords can't stop you from doing this. Nor do you need
| their permission, a permit, or special insurance.
|
| The point is that this stuff is cheap, easy, and pretty much
| plug and play. Roofs aren't a whole lot more complicated than
| this from a technical point of view. You need more panels and
| more expensive equipment and you probably need some
| professional electricians and installers to do the work.
|
| The rest is just nonsense that relates more to your local
| government and legislation than anything being inherently
| expensive or difficult. I'd suggest reminding your local
| politicians of their responsibilities during the next elections
| and maybe voting for the ones that aren't being jerks on this
| front.
|
| Otherwise, solar panels are pretty reliable and generally
| covered by long warranties. Repairing them is mostly not a
| thing, somebody would come and simply replace them. I doubt
| that a lot of solar panel companies and installers are
| suffering a lot under the enormous burden of this happening all
| the time for the simple reason that it this isn't a thing.
| xnx wrote:
| Balcony solar sounds brilliant and probably has clear ROI.
| Rooftop solar is an awkward middle between grid-scale solar
| and balcony solar. Rooftop solar might only make sense in
| developed countries through subsidies.
| bryanlarsen wrote:
| The majority of the cost of electricity in most jurisdictions
| is distribution, not generation. Grid-solar still requires
| distribution, so it is always going to have significant cost
| even if the cost of generation is insignificant.
|
| If it can remove the need for a grid-tie, then rooftop solar
| can be significantly cheaper and more efficient. Can be, but
| isn't yet, because enough overcapacity and storage to eliminate
| the need for a grid tie is still too expensive.
| s1artibartfast wrote:
| This is exactly the challenge. Here in California wholesale
| solar plant sell power for 0.03-0.04 kwh. Cost at the meter
| is 0.45/kwh.
|
| Rooftop is competitive with the meter price, but unless you
| can cut the cord entirely, connection fees and rates will
| just keep increasing proportionally
| srameshc wrote:
| There was a startup that was doing something similar, can't find
| it but their entire business was built on providing similar
| service.
| larodi wrote:
| hundreds of people do this at the moment worldwide, no surprise
| someone is productivising it, or many people are.
| MaxDPS wrote:
| I applied at a company called WattTime a few years ago. I
| didn't get the job but their work involved some of that. It
| sounded really interesting.
|
| https://watttime.org/about-us/climate-trace/
| ximeng wrote:
| https://www.transitionzero.org/products/solar-asset-mapper
| perhaps
| unit149 wrote:
| Querying overhead nadir satellite imagery - captured at a
| vertical angle relative to its spatial position - and feeding it
| into Geo Deepmind's ML program gives us roof-segmentation data.
| Ostensibly, annual flux prediction imagery in the global south,
| after being ran in Google's Solar API gives us some enhanced DSM-
| RGB imagery.
| buckle8017 wrote:
| Estimate for a house in SF with a typical roof and typical
| electric bill.
|
| $20k upfront cost.
|
| $4k in savings over 20 years.
|
| That's an implied rate of return of 0.9% annually.
|
| No thanks.
| stainablesteel wrote:
| i've heard of some business models that install these and have
| you pay what would be the difference to your electric bill to
| the company until they pay themselves off, not sure if the
| panels last long enough to make that work though
| ccozan wrote:
| Yes. In Germany they are selling a lot of models, but none, I
| mean, really, none asked about the rentability. So I went to
| a neighbour who just installed his 25kW and was very proud
| and happy, and asked him, in how many years is the return of
| investment. Siderated, he could not answer and then a few
| days later, with a very stern face: 25 years or more because
| if more people install these, the price that the city is
| paying for the pumped energy goes down.
|
| So no. 20kw is not the answer. I showed my setup: 3.5kw + big
| battery. Pays the bill approx 60 70% of the daily usage.
| Investment payback : 5years.
| scotty79 wrote:
| What if he added previous generation crypto miner (so it's
| cheap) and use the excess electricity instead of selling it
| to the grid? This could also save some money on heating in
| winter unless he has a heat pump priced in already.
| PaulDavisThe1st wrote:
| prev gen crypto mining is phenomenally inefficient in
| terms of energy that ends up being converted to heat, but
| it is absolutely not what you would use to take
| electricity and create heat given any other choices.
| scotty79 wrote:
| What are other choices? Heat pump is obviously the best
| but any other thing is just electric heater with 100%
| efficiently of heat generation. Pushing some bits around
| doesn't change that. I guess for some applications you
| might prefer higher temperatures but for residential
| heating crypto mining is as good as anything else, right?
| ccozan wrote:
| this guy is a carpenter :). cryto mining would sound like
| chinese to him...
| BonoboIO wrote:
| Damn, your neighbor got robbed by the installer ...
| throwaway2037 wrote:
| 25kW? That is crazy huge! How many panels? What does this
| guys house (mansion!?) look like? Google tells me that
| average installation size is about 7-8kW.
| ccozan wrote:
| Is not that big. you have approx 400W ( mine are 440W) on
| a 2sqm. Hi sroof is like 15 x 8 m. and is not fully
| covered. You can easily reach 25kw.
| buckle8017 wrote:
| Yes I think in general those are a better deal for the
| homeowner.
|
| They're a terrible deal for those companies investors though.
|
| Presumably at some point they go bankrupt and sell your roof
| at auction??? weird setup
| dzhiurgis wrote:
| One of these wouldn't sign me up as they couldn't offer any
| savings (92% of my use is off peak, around 16ct NZD (9 USD) /
| kWh).
|
| A lot of the time such companies pray on people on stupid
| plans (or those paying thru the nose for "exclusively
| renewable") power.
| nine_k wrote:
| This exactly the case when a battery would make an immense
| difference.
|
| (9 USD / kWh sounds terrifying. Not only an electric kettle
| begins to cost you; probably playing computer games at high
| quality / resolution comes with a noticeable price tag in
| electricity that the GPU would eat.)
| bruce511 wrote:
| I think he meant 9 USD cents per kw. (He included ct with
| NZD but forgot it with USD.)
| throwaway2037 wrote:
| Woah, your electricity is so cheap! Is it mostly hydro?
| prdonahue wrote:
| Was that paired with a battery? Under NEM3 (and reduced net
| metering rate), it doesn't make sense to install PV in
| California without a battery.
| ggreer wrote:
| How are you calculating that? Solar installations are around
| $2.50-$3.50 per watt, so $20k would get you 6-8kW. Assuming
| actual output is 10% of capacity, that's 14-19kWh/day or
| 5,000-7,000kWh per year. Current residential electricity prices
| in SF are 38.9 cents per kWh[1], so that's $2,000-2,700 per
| year in savings, or $40-54k over 20 years. The actual amount
| saved depends on how much electricity you're consuming during
| peak times, but I doubt that number is off by a factor of 10.
|
| 1. https://www.bls.gov/regions/west/news-
| release/averageenergyp...
| buckle8017 wrote:
| I didn't calculate anything I just put in an address and a
| monthly electricity bill.
|
| https://sunroof.withgoogle.com/
| Retric wrote:
| Ahh, ok the tool sucks it doesn't seem to calculate based
| on your current cost per kWh or the local cost per kWh.
|
| It's ignoring inflation on those calculations, acting like
| your electric bill will be the same in 20 years. It's also
| ignoring residual value in the system after 20 years they
| typically last 25-30, and you don't pay taxes on savings.
|
| There install estimates where also really high for my area,
| but I don't know if that's a general issue.
| patrickhogan1 wrote:
| Your electric bill 20 years from now is just as likely to
| go down as it is to go up.
|
| In two decades, we could see advancements like mobile
| generators offering free power, ultra-affordable battery
| packs delivered to homes to meet energy needs, or even
| the widespread adoption of low-cost fusion energy.
|
| The key takeaway is that predicting the future cost of
| electricity is as challenging as it was to predict
| today's solar energy costs--now far lower than anyone
| expected.
| Retric wrote:
| None of what you just said is even vaguely realistic.
| Prices can't drop below zero but they can easily more
| than double, so even if you assume equal odds in either
| direction it doesn't cancel out. Worse, any physical
| device is going to have a cost to produce it which
| requires charging people to use it thus they can't even
| drop to 0.
|
| Beyond that none of their prices or timelines are
| accurate, even ignoring the issues with inflation.
| bagels wrote:
| When did PGE prices ever go down?
| patrickhogan1 wrote:
| Neither option I mentioned would require PGE or a
| centralized entity. Both options would be off-grid.
| throwaway2037 wrote:
| > mobile generators offering free power
|
| Wow, where is this magical place? I want to move there.
| :)
| patrickhogan1 wrote:
| Mobile Solar Generator Feasibility
|
| With solar technology, powering a home with a mobile
| generator is possible. Yes, the generator and batteries
| will have associated costs, but the long-term benefits
| make it worthwhile. This assumes uninterrupted access to
| sunlight over the next 20 years without new restrictions.
|
| Key Considerations:
|
| Energy Need: The average home uses 30 kWh/day, requiring
| 6 kW/hour over 5 peak sunlight hours.
|
| Multijunction Panels: Lab efficiencies are already at 47%
| (2023), and with 20 years of progress, 60% efficiency is
| probable.
|
| Efficiency Impact: At 60% efficiency, panels generate 600
| W/m2, requiring 10 m2 (e.g., 2 m x 5 m) to meet energy
| needs. This size fits on most home roofs or could be
| mounted on a pole or hung through an apartment window.
|
| System Components:
|
| High-efficiency solar panels.
|
| 30 kWh battery storage for nighttime or cloudy days. An
| inverter to convert solar DC power to home AC power.
| Outcome:
|
| A mobile solar generator with advanced panels and
| efficient storage provides a sustainable and portable
| solution for powering homes.
| Retric wrote:
| Doing that is what installing solar _is_
|
| So you're assuming the big competition for home solar
| is... home solar but ignoring what makes home solar
| expensive (permits, electricians, tariffs etc panels are
| already shockingly cheap). Installing solar in 15 years
| also means you've lost 15 years of cheap solar power and
| are buying panels after inflation, waiting just hasn't
| seen instillation costs drop for a while.
|
| But you're also wildly mistaken about the rest, it's not
| actually 47% or now 47.1% efficient when placed outside.
| Panels get more efficient as extreme levels of light so
| people going after records create wildly irrelevant
| numbers as a dick measuring contest.
|
| Further the day someone invents 60% efficient panels
| isn't the day we put those suckers into mass production
| we hit 40% in 2006, but they are nowhere near
| commercially viable for home installations. We might see
| widespread use of 60% efficient panels long after we're
| dead, but that's not exactly relevant for these
| calculations.
| patrickhogan1 wrote:
| It seems like we're talking past each other. My main
| point, as stated in the parent response, is that there is
| a plausible future where energy prices, adjusted for
| inflation, could decline rather than continually
| increase.
|
| Many here are relying on inductive reasoning, arguing
| that since this hasn't happened historically, it can't
| happen in the future. I'm presenting a counterpoint: with
| current technology and 20 years of advancement, this
| outcome is entirely possible.
|
| To clarify, I'm not suggesting that mobile generators and
| solar panels would be free. Rather, the energy they
| generate could become effectively free. The current
| challenge is that centralized grids are often necessary
| because we can't store enough solar energy in batteries.
| However, with advancements in battery technology over the
| next 20 years, it could become possible to go completely
| grid-less. If that happens, we could see significantly
| lower energy prices--something we should remain as open
| to as the possibility of higher prices, all on an
| inflation-adjusted basis.
| r00fus wrote:
| Now you're sounding all pie in the sky. The cold hard
| reality is that hedge funds and billionaires control most
| power utilities and lobby governments to keep the cash
| flowing.
|
| We know for certain that pricing is going to get really
| bad in CA due to a 2022 law that permits PG&E and other
| utilities to charge large connection fees based on your
| income (will probably hit in 2026).
|
| I would gladly be the counterparty to any wager that 20
| years from now electricity is going to be cheaper.
| notatoad wrote:
| sunroof was a 2015 project. if they haven't adjusted their
| cost estimates since they launched it, it could be wildly
| overestimating things.
| gloflo wrote:
| Same for panel efficiency
|
| https://en.m.wikipedia.org/wiki/Solar-
| cell_efficiency#/media...
| malfist wrote:
| Solar installations have a 30% tax rebate currently. So your
| $20k would actually be $12k, makes the math a bit better.
|
| Plus, are you counting in inflation of electricity prices in
| those 20 years? I'm sure electricity isn't going to get cheaper
| tppiotrowski wrote:
| As someone who has researched DSM availability across the globe,
| Google's Solar API is a top contender. Other option is government
| LiDAR surveys but the coverage, file formats, projections, etc
| are all fragmented. I think it would be great for the mapping
| community to create a world wide DSM map tile dataset similar to
| the ground elevation tile dataset that contour lines and 3D
| terrain views are generated from. Maybe someone is already
| working on this?
|
| In the article they show areas where their approach can generate
| DSM although this is just the potential areas and not the areas
| where data is already available. :(
| morbicer wrote:
| Does DSM stand for Digital Surface Model?
|
| Thos exact abbreviation is so overloaded that it doesn't hurt
| to list the words once.
| pyaamb wrote:
| This is really incredible. If they could plug in local utility
| prices and come up with estimate for dollars saved per year, that
| would be an incredible conversation starter for homeowners who
| might not have considered taking on a home solar project
| otherwise.
| rrr_oh_man wrote:
| > incredible conversation starter for homeowners who might not
| have considered taking on a home solar project otherwise
|
| Once you do the math in a Northern country (sans subsidies)
| it's not as compelling as you might think.
| bruce511 wrote:
| By "Northen" I assume you mean Europe, and (most of) USA?
|
| I live near the 33rd parallel South. Since installing solar
| my annual grid requirements are around 30% of before solar
| [1] - even as my actual consumption has risen [2].
|
| As far as "Northern" goes countries in my latitude north (or
| better) include India, Mexica, all of Africa, most of China,
| and so on. So for most people living in the north it is
| compelling [4].
|
| [1] a very large fraction of my grid usage is really cold,
| wet conditions for 6 weeks in winter. A combination of low
| generation and high usage for heating.
|
| [2] cooling in summer is free, so we run the aircon a lot
| more. Plus things like slow-cooking etc are free as well.
|
| [4] my return on investment (grid cost of generated
| electricity over capital invested) is 16.7%. Projected
| lifespan is 10 years for battery and inverter, 25 years on
| panels, 50 years on wiring.
| HPsquared wrote:
| Northern places (thinking UK here) don't use AC in summer,
| the economics are different.
| littlestymaar wrote:
| > By "Northen" I assume you mean Europe, and (most of) USA?
|
| People wrongly assume that you can put Europe and the US in
| the same basket (because temperature-wise climate is
| comparable), but half of Europe is further north than
| Montreal, and almost all of it is beyond Philadelphia, so
| no you can't really say "Europe and most of the US".
| rgmerk wrote:
| Because (at least in the USA) the soft costs are excessive:
|
| https://pv-magazine-usa.com/2022/11/16/tackling-soft-
| costs-a...
| jvanderbot wrote:
| Considering "Customer aquisition" as a cost is really funny
| (and that seems to be the "soft cost" discussed).
|
| In Minnesota the "deal" for solar if you cannot DIY / off-
| grid is just meh.
|
| They do not allow use of battery backups or cutover, they
| cut out when the power goes out, and they "credit" you to
| reduce your overall bill. You can make money if you produce
| more power in sunny warm times than you use year around (at
| least while you are the only one!), but the dream of energy
| independence at a local scale just isn't there yet.
|
| What I want is something that offsets my grid use
| (potentially to zero but not negative), so that I can use
| grid or solar to charge my EV and a whole-home battery bank
| with three days reserve. I don't care about becoming part
| of the overall grid solution, but in city limits, it
| appears I must, and that necessitates extra equipment and
| rules out my backup use case.
|
| And yet, I get constant calls and fliers about it - all
| "soft costs" - no matter how much I say no.
| notatoad wrote:
| like this? https://sunroof.withgoogle.com/
| geewee wrote:
| Aw, I hoped for a second for global coverage.
| ak2372 wrote:
| ,$
| barbegal wrote:
| An interesting use for satellite in future will be accurate
| estimation of solar power output in the very near future e.g. in
| the next hour period such that grid operators can adjust storage
| and demand to get a balanced grid. At the moment we can't do
| these predictions as we don't know where solar panels are in
| relation to any passing clouds.
| treyd wrote:
| I'm sure you could get that data from public permitting
| filings. And failing that, train an AI model on scraped Google
| Maps imagery. I would be surprised if people aren't doing it
| already.
| sanj wrote:
| I had the privilege of working with the heart and soul of this
| solar rooftop work.
|
| Carl is a mensch.
|
| He's also the brilliance behind
| https://blog.google/technology/ai/ai-airlines-contrails-clim...
| 4b11b4 wrote:
| This is where Google much more than
|
| - GCP vs AWS
|
| - Gemini vs ChatGPT
|
| etc
| navaed01 wrote:
| This is a very neat exercise but I don't think it's going to
| create change. These models already exist and I've never met
| anyone who said their reason for not investing in solar is
| because they felt the accuracy of existing models is not good
| enough. I say this as someone who lives on a part of the world
| where a large % of the inhabitants could have solar but do not -
| and I find it sad, frustrating and puzzling.
|
| Biggest blockers for solar are (total conjecture) : 1- Inertia -
| flat out. 2- Long-term ROI is not totally clear - How long till I
| need to replace, roof damage, ability to hold up in storm. 3-
| Cost - You need to invest sig $ to see your electric bill
| decrease meaningfully. Gov subsidies are nowhere near where they
| should be.
|
| I am praying for a major breakthrough in cell efficiency to make
| it a no brainer. Does anyone have any insight on that?
| achillesheels wrote:
| I think it has to do with the assurance of the warranty. The
| ROI is loooong; solar contractors can go out of business
| leaving the parts on the roof lacking in the promised energy
| savings. Who wants to litigate against a bankrupt company?
| tuatoru wrote:
| Do you get the depreciated value added on to the house price if
| you sell? This was always a big problem for solar hot water
| systems. If the payback period is seven years but the average
| house turnover is five years, then there is little incentive.
|
| Gov subsidies are the government giving the tax money of poor
| people who cannot afford houses to rich people who have houses.
| Highly regressive. Your PV system should stand on its own
| merits without holding out your hand to other taxpayers to fund
| you.
| nick3443 wrote:
| Seems like qcells are on the road to a ~28% solution with
| silicon-perovskite tandem cells. When I researched for my own
| home install, it seems most of the cost is actually install
| labor, markup, electricians rates for hookup, etc. The plain
| BOM is close to $1-1.50 per watt for cells plus inverters and
| mounting hardware, but people still charge $3+ for systems.
| bagels wrote:
| I have low confidence in the whole industry. High prices, holes
| in my roof, and many reports of systems being installed poorly
| with warranties not being honored.
| throwaway2037 wrote:
| This chart on the progress of PV cell efficiencies always blows
| me away:
| https://en.wikipedia.org/wiki/Photovoltaics#/media/File:NREL...
| hndude wrote:
| related: NSRDB (Nat'l Solar Radiation Database) Viewer from the
| National Renewable Energy Lab - https://nsrdb.nrel.gov/data-
| viewer
| mlsu wrote:
| This is fine and all, but each individual having a solar panel
| introduces a lot of issues.
|
| Your energy bill is about 1/4 or 1/3rd distribution. As you take
| less power from the grid because of the solar on your roof, that
| proportion grows larger and larger.
|
| At the same time, the power company makes less money off of you,
| because you are using less power. Therefore, they have less money
| to invest in distribution, which means they must increase
| distribution fees further to stay a going concern. This is to say
| nothing of the ballooning costs of distribution in general
| (nimbyism, permitting fees, can't build jack shit in this country
| for no good reason etc.).
|
| Therefore: in the hypothetical where everyone has solar rooftops,
| we all effectively pay the grid operator _only_ for dirty
| /offpeak power. This makes the grid operators look bad to
| everyone (they're using dirty power, aren't we trying to fight
| climate change!? Why is my electricity bill astronomical, even
| though I only use a tiny bit of power!?) and puts them in an
| impossible situation -- they're stuck between capped profits,
| creating expensive clean power at off-peak hours, and limited
| cash in general, since their expensive power plants are dormant
| half the time. Yet they still must deliver power to their
| customers, 24/7.
|
| People have to have 24/7 electricity, even though the solar on
| their house does not cover them 24/7. It's illegal to sell a
| house that is not connected to the grid in most areas. Therefore,
| consumers must pay for the _option_ of using electricity in off-
| peak hours. Everyone will be upset. The grid operator, who is
| constantly thrashed by politicians who insist on their using
| clean power, their customers who are enraged at them for the
| seemingly exorbitant electric bills (which are mostly
| distribution).
|
| The upside is that the grid is more resilient, but as others have
| mentioned, only if significant investments in local distribution
| are made (i.e. the ability to very dynamically/granularly pump
| power back up, from house to grid). Which is a big capital
| investment that the grid operators will not be able to afford.
|
| All this is downstream of the fact that it is hugely inefficient
| to put a ton of tiny solar panels all over the place, where they
| cannot be installed, cleaned, maintained, replaced cheaply. It's
| just way less expensive per watt to put a bunch of solar panels
| in one spot on cheap land in the desert and pipe it through the
| existing distribution network.
|
| Everyone _will_ pay for that resilience, in their electric bill,
| one way or another.
| tsycho wrote:
| Valid points. Is there a known solution to this, even if it's
| too expensive today?
|
| Would it make sense for local electricity companies to go full
| solar with large battery backups? Or are batteries too
| expensive, or don't last long enough, for this to be feasible?
|
| What about a wind+solar combination? Both of them are unlikely
| to go offline at the same time.
|
| I see articles that the cost of wind and solar keep going down
| every year at a rapid rate, and the same for battery tech too.
| How far are we from where the costs are low enough for cities
| to have their own reliable grids composed of renewable energy?
| scotty79 wrote:
| The solution to that is as much distributed storage as
| possible and cryptocurrency mining (or LLMs) for monetizing
| excess energy.
| mlsu wrote:
| Sorry, capex for crypto -- let alone llm (datacenters must
| be on 100% of the time to pay nvidia) -- is way too high.
| It must see high utilization for amortization to be
| favorable.
|
| You only see crypto in areas that have really cheap, 24/7
| power. Big crypto mining operations are only built near
| remote hydroelectric power stations, or worse, natural gas
| or coal rich areas. Places where fossil fuels are made but
| that don't have easy/cheap access to refineries, rail
| lines, or pipelines.
| scotty79 wrote:
| You are probably right about LLM because barely anybody
| tries to use distributed compute (like folding at home
| was using).
|
| But crypto is running 24/7 because energy price is still
| positive so people buy latest, most efficient hardware to
| be as efficient as possible. But latest hardware is
| expensive. You can buy prev gen mining hardware for
| peanuts comparatively. It can make you money if you run
| it when you have more energy than you can use or sell.
| PaulDavisThe1st wrote:
| > Would it make sense for local electricity companies to go
| full solar with large battery backups?
|
| Sure. But opposition to those battery energy storage systems
| (BESS) is intense and growing.
| mlsu wrote:
| The most sensible solution in the short term is to keep the
| distribution that we have in place and aggressively invest in
| large solar plants coupled with very large battery systems to
| ease the duck curve.
|
| Individual homeowners can do their part with solar + heat
| pumps to shift that duck curve. Power rates should see way
| more wild swings: 0c at the trough around 11am-2pm, $.50 at
| the 5pm peak. That aligns consumers to make sensible
| investments, either the energy they use or the energy they
| produce/store.
|
| Smart charging of cars, so that those car batteries can help
| shift the load? But that requires global coordination that is
| nonexistent today.
|
| Solar is no doubt _the_ energy solution, there 's really
| nothing better. It's low maintenance and lasts a long time,
| capital scalable, and can be deployed basically anywhere.
| Solar is far and away the cheapest thing for about 70% of our
| energy needs. For the last 30% that is very tough to squeeze
| out -- that baseline power for 24/7 stuff like aluminum
| smelters, datacenters -- you basically have: high voltage
| transmission (only available if you have land to your west),
| big battery banks (tenable, but only if batteries follow
| solar's dramatic reduction in cost), or nuclear (but requires
| a big culture change that I cannot really imagine). Or fossil
| fuels but those are not good obviously.
|
| Basically any of the other green stuff (hydro, wind,
| geothermal) can't be built at any price most places.
| kla-s wrote:
| The real solution is the dynamization of electricity prices.
| This needs some adjusting from your average consumer but not
| a lot if done right. In Germany there are startups like 1.5C,
| Enpal etc which will sell you a heat pump, solar, ev charger
| pack with some "smarts", switch you over to a dynamic pricing
| electricity contract and then claim to optimize the overall
| cost (i have no direct experience of my own). If you are
| willing to take a small amount of temperature swing your
| house is a big thermal battery (even more so if you have a
| heat pump to water with a big, well insulated reservoir),
| your ev is a battery with vehicle to grid. With this you can
| shift your main loads a good amount. Washing machines and
| dryer as well as cooking/baking might be slightly more
| problematic/harder to shift, though the car battery should be
| more than enough for average evening cooking and i have seen
| washing machines/dryers which can take an external signal as
| to run when the price is low/there is excess electricity...
| theoreticalmal wrote:
| Wow, all this goes to show that distributed power storage
| systems will absolutely destroy contemporary power utility
| companies
| jodrellblank wrote:
| > " _It 's just way less expensive per watt to put a bunch of
| solar panels in one spot on cheap land in the desert and pipe
| it through the existing distribution network._"
|
| If that were true people wouldn't be buying solar panels for
| their homes because grid electricity would be "way less
| expensive" and it wouldn't be worth it. Which means either it
| isn't true, or the grid companies are too busy profiteering and
| it's not "putting the grid operators in an impossible position
| where everyone unfairly hates them" it's "grid operators
| putting themselves into an impossible position where everyone
| deservedly hates them".
| mlsu wrote:
| No. People put solar panels on their homes, but crucially,
| they still receive power from the grid _when their solar
| panels are not producing electricity_.
|
| People who don't have solar panels pay for electricity at
| 11:00AM. That's lucrative for the grid operator _between
| 11:00-3:00 only_ -- when the duck curve is low. When demand
| peaks at 5-6pm, the grid operator pays boatloads of money to
| import power from elsewhere, burn expensive fossil fuels to
| service the demand.
|
| Crucially, the grid operator is limited on pricing: they
| cannot "gouge" consumers at 5pm -- they _must_ keep prices
| below a cap. Utility pricing is extremely regulated, it 's
| set essentially by the state.
|
| What you're doing when you set up solar panels on your home
| is actually freeloading. Your electric bill is less than it
| should be: you _take_ power (at an artificially low rate)
| when it 's super expensive, and don't take it when it's super
| cheap. This is very very bad business for the grid operator.
| They're also mandated by law (!) to keep your house hooked up
| to the grid and run distribution lines all over the place.
| Just in case you want to plug your car or run your AC at 5pm.
| Try getting a permit to build a new transmission line
| _anywhere_ and see whether that 's good business. If you have
| solar panels on your house, you are being subsidized by them
| -- not the other way round!
|
| Timing is everything here. The United states has on the order
| of _minutes_ of energy storage across the electric grid.
| bensandcastle wrote:
| marginally relevant. space based dawn dusk LEO solar infra is the
| answer. vastly more power than we'll ever get on the surface of
| this rock and then onto Sol.
| myroon5 wrote:
| Related:
|
| _Global Solar Power Potential Map_ -
| https://news.ycombinator.com/item?id=40303570 - May 2024
| looofooo0 wrote:
| I am sceptical about putting PV on roofs, seems a lot of hassle
| and waymore expensive then using just flatground:
| https://en.wikipedia.org/wiki/Bhadla_Solar_Park Any additional
| money spent on it, could have helped to install more PV or
| batteries.
| Delmolokolo wrote:
| Every PV system on a roof means producing and consuming energy
| directly.
|
| In Germany we already have large distance energy transfer
| problems.
|
| And PV is so cheap now + battery, you get independence / real
| freedom out of the box.
|
| If you have valuable space on the ground and want to remove the
| utilization of it, sure but I prefer it on the roof were it
| doesn't do that.
|
| But yes next to autobahns or other smart locations yes put it
| on the ground.
|
| But when I invest in myself I will not sponsor pv somewhere
| else
| victorbjorklund wrote:
| In general yes but due to both taxes/regulations and real
| issues with the grid it is "easier" to just consume what your
| produce vs producing and selling to the grid. And since space
| is limited on most peoples property if you live an urban
| setting then roof might be the only place to put it. If you got
| plenty of space though roof is a worse place than the ground
| from almost every point of view.
| neves wrote:
| Unfortunately the beta is available just for enterprises. I'd
| love to run it for my house.
| bokohut wrote:
| I used an early version of the PV roof tool in 2020 for my own PV
| roof design. The front of my rectangle shaped home faces exactly
| North and therefore all sides are respective to exactly E/W/S.
| Given my professional experiences and knowledge awareness of
| photons I therefore opted to cover my entire roof in PV
| collecting technology and not just what faces direct sunlight, if
| one can see outside during daylight hours then the PV is
| functioning. Case in point, right now it is currently very cloudy
| and rainy here in the NE,USA and the roof is still generating 700
| watts while my home's base load demand of 400 watts has the
| overage of 300 watts going to batteries. I have had this system
| for 3 years now and my choice to have such a system proved itself
| in our first outage when everyone else was panicking in the dark
| for hours. I sat relaxed and watched others in great stress and
| anxiety planning on how to preserve their refrig/freezers while
| visually panicking over their sump pumps not running in their
| basements. PV with a battery is a quality of life choice that
| directly impacts one's health and what price do you put on your
| health? I will also share with such sites that the energy and
| cost saving estimates are very much often wrong since the energy
| data is generalized for everyone and energy use per person
| significantly varies, some estimates are laughable to only me
| since I have my families own _real world_ data for the last
| decade. I have also tracked our entire resource consumption at
| home for nearly a decade now, yes I am a data nerd to the
| extremes, and not only does such a solution save one GREAT stress
| and anxiety when it matters most but it also greatly reduces
| variable financial expenses and can also make one revenue.
|
| Proactive versus reactive : The data doesn't lie, people do.
|
| Stay Healthy!
| s1artibartfast wrote:
| > sat relaxed and watched others in great stress and anxiety
| planning on how to preserve their refrig/freezers while
| visually panicking over their sump pumps not running in their
| basements.
|
| I hope you at least offered to help...
| bokohut wrote:
| Yes, I did mention this in closing: "can also make one
| revenue."
| s1artibartfast wrote:
| I was commenting on the sentiment of sitting back and
| relaxing watching your neighbors struggle. I don't think
| revenue relates to it
___________________________________________________________________
(page generated 2024-12-20 23:02 UTC)