11 ms·

Satellite powered estimation of global solar potential

265 points by jonbaer 2y ago

HocusLocus 2y ago
"We lose a little on each transaction, but make up for it in volume."
janitorHenry 2y ago
Builders: optimize energy capture, put roof planes directed south (in northern hemisphere).
- elric 2y ago
  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 2y ago
    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 2y ago
    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 2y ago
      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 2y ago
      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 2y ago
      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 2y ago
      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 2y ago
    This problem has been know for well over a decade...
- szvsw 2y ago
  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 2y ago
    > 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 2y ago
      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…
- edent 2y ago
  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.
deleted 2y ago
[deleted]
ben_w 2y ago
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 2y ago
  > 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 2y ago
    The correct solution is 10.7Pwh. We are often exposed to 'Peta' when dealing with data. https://en.wikipedia.org/wiki/Metric_prefix https://en.wikipedia.org/wiki/Metric_prefix
  - jeffbee 2y ago
    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 2y ago
    I was reading https://en.wikipedia.org/wiki/International_System_of_Units 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 - 10.7×10³ - 1.07×10⁴ - 10.7e3 - 1.07e4 - 29E8₁₆
jeffbee 2y ago
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 2y ago
  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 2y ago
    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 2y ago
      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.
    - 2y ago
xnx 2y ago
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 2y ago
  I'll take 3kW on my rooftop over 5kW in billionaire's company.
- tejtm 2y ago
  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.
- szvsw 2y ago
  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 2y ago
    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 2y ago
  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/south-australia-renewable-energy-targets-international-template-solar-power https://www.theguardian.com/environment/article/2024/sep/08/... Perfect is the enemy of good
srameshc 2y ago
There was a startup that was doing something similar, can't find it but their entire business was built on providing similar service.
- larodi 2y ago
  hundreds of people do this at the moment worldwide, no surprise someone is productivising it, or many people are.
- MaxDPS 2y ago
  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/ https://watttime.org/about-us/climate-trace/
- ximeng 2y ago
  https://www.transitionzero.org/products/solar-asset-mapper https://www.transitionzero.org/products/solar-asset-mapper perhaps
bangaloredud 2y ago
[flagged]
- blacksmith_tb 2y ago
  And they're worse than belching smokestacks, somehow? Criticisms like calling wind power turbines "bird shredders" are either crocodile tears from the Drill Baby Drill conservatives (who curiously never cared much about birds until now - except for shooting them with shotguns, that is) or from Quixotic enviros who can't accept any tradeoffs, no matter how dire our circumstances get.
unit149 2y ago
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 2y ago
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 2y ago
  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 2y ago
    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.
    - BonoboIO 2y ago
      Damn, your neighbor got robbed by the installer …
    - scotty79 2y ago
      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 2y ago
        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.
tppiotrowski 2y ago
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 2y ago
  Does DSM stand for Digital Surface Model? Thos exact abbreviation is so overloaded that it doesn't hurt to list the words once.
  - tppiotrowski 2y ago
    Yes. There are planet wide DEM (Digital Elevation Model) datasets which record ground level elevations but no planet wide set for DSM which includes built structures and vegetation.
deleted 2y ago
[deleted]
pyaamb 2y ago
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 2y ago
  > 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 2y ago
    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 2y ago
      Northern places (thinking UK here) don't use AC in summer, the economics are different.
    - littlestymaar 2y ago
      > 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”.
barbegal 2y ago
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 2y ago
  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 2y ago
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-climate-change/ https://blog.google/technology/ai/ai-airlines-contrails-clim...
4b11b4 2y ago
This is where Google much more than - GCP vs AWS - Gemini vs ChatGPT etc
navaed01 2y ago
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?
- bagels 2y ago
  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.
- achillesheels 2y ago
  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 2y ago
  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 2y ago
  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.
hndude 2y ago
related: NSRDB (Nat'l Solar Radiation Database) Viewer from the National Renewable Energy Lab - https://nsrdb.nrel.gov/data-viewer https://nsrdb.nrel.gov/data-viewer
mlsu 2y ago
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 2y ago
  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?
bensandcastle 2y ago
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.
huntergackley 2y ago
[flagged]
myroon5 2y ago
Related: Global Solar Power Potential Map - https://news.ycombinator.com/item?id=40303570 https://news.ycombinator.com/item?id=40303570 - May 2024
looofooo0 2y ago
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 https://en.wikipedia.org/wiki/Bhadla_Solar_Park Any additional money spent on it, could have helped to install more PV or batteries.
- Delmolokolo 2y ago
  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
- deleted 2y ago
  [deleted]
- victorbjorklund 2y ago
  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 2y ago
Unfortunately the beta is available just for enterprises. I'd love to run it for my house.
bokohut 2y ago
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 2y ago
  > 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 2y ago
    Yes, I did mention this in closing: "can also make one revenue."

265 points by jonbaer 2y ago

HocusLocus 2y ago

"We lose a little on each transaction, but make up for it in volume."

janitorHenry 2y ago

Builders: optimize energy capture, put roof planes directed south (in northern hemisphere).

elric 2y ago
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 2y ago
  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 2y ago
  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 2y ago
    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 2y ago
    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 2y ago
    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 2y ago
    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 2y ago
  This problem has been know for well over a decade...
szvsw 2y ago
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 2y ago
  > 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 2y ago
    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…
edent 2y ago
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.

deleted 2y ago

[deleted]

ben_w 2y ago

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 2y ago
> 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 2y ago
  The correct solution is 10.7Pwh. We are often exposed to 'Peta' when dealing with data. https://en.wikipedia.org/wiki/Metric_prefix https://en.wikipedia.org/wiki/Metric_prefix
- jeffbee 2y ago
  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 2y ago
  I was reading https://en.wikipedia.org/wiki/International_System_of_Units 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 - 10.7×10³ - 1.07×10⁴ - 10.7e3 - 1.07e4 - 29E8₁₆

jeffbee 2y ago

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 2y ago
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 2y ago
  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 2y ago
    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.
  - 2y ago

xnx 2y ago

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 2y ago
I'll take 3kW on my rooftop over 5kW in billionaire's company.
tejtm 2y ago
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.
szvsw 2y ago
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 2y ago
  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 2y ago
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/south-australia-renewable-energy-targets-international-template-solar-power https://www.theguardian.com/environment/article/2024/sep/08/... Perfect is the enemy of good

srameshc 2y ago

There was a startup that was doing something similar, can't find it but their entire business was built on providing similar service.

larodi 2y ago
hundreds of people do this at the moment worldwide, no surprise someone is productivising it, or many people are.
MaxDPS 2y ago
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/ https://watttime.org/about-us/climate-trace/
ximeng 2y ago
https://www.transitionzero.org/products/solar-asset-mapper https://www.transitionzero.org/products/solar-asset-mapper perhaps

bangaloredud 2y ago

[flagged]

blacksmith_tb 2y ago
And they're worse than belching smokestacks, somehow? Criticisms like calling wind power turbines "bird shredders" are either crocodile tears from the Drill Baby Drill conservatives (who curiously never cared much about birds until now - except for shooting them with shotguns, that is) or from Quixotic enviros who can't accept any tradeoffs, no matter how dire our circumstances get.

unit149 2y ago

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 2y ago

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 2y ago
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 2y ago
  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.
  - BonoboIO 2y ago
    Damn, your neighbor got robbed by the installer …
  - scotty79 2y ago
    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 2y ago
      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.

tppiotrowski 2y ago

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 2y ago
Does DSM stand for Digital Surface Model? Thos exact abbreviation is so overloaded that it doesn't hurt to list the words once.
- tppiotrowski 2y ago
  Yes. There are planet wide DEM (Digital Elevation Model) datasets which record ground level elevations but no planet wide set for DSM which includes built structures and vegetation.

deleted 2y ago

[deleted]

pyaamb 2y ago

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 2y ago
> 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 2y ago
  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 2y ago
    Northern places (thinking UK here) don't use AC in summer, the economics are different.
  - littlestymaar 2y ago
    > 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”.

barbegal 2y ago

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 2y ago
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 2y ago

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-climate-change/ https://blog.google/technology/ai/ai-airlines-contrails-clim...

4b11b4 2y ago

This is where Google much more than - GCP vs AWS - Gemini vs ChatGPT etc

navaed01 2y ago

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?

bagels 2y ago
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.
achillesheels 2y ago
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 2y ago
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 2y ago
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.

hndude 2y ago

related: NSRDB (Nat'l Solar Radiation Database) Viewer from the National Renewable Energy Lab - https://nsrdb.nrel.gov/data-viewer https://nsrdb.nrel.gov/data-viewer

mlsu 2y ago

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 2y ago
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?

bensandcastle 2y ago

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.

huntergackley 2y ago

[flagged]

myroon5 2y ago

Related: Global Solar Power Potential Map - https://news.ycombinator.com/item?id=40303570 https://news.ycombinator.com/item?id=40303570 - May 2024

looofooo0 2y ago

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 https://en.wikipedia.org/wiki/Bhadla_Solar_Park Any additional money spent on it, could have helped to install more PV or batteries.

Delmolokolo 2y ago
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
deleted 2y ago
[deleted]
victorbjorklund 2y ago
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 2y ago

Unfortunately the beta is available just for enterprises. I'd love to run it for my house.

bokohut 2y ago

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 2y ago
> 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 2y ago
  Yes, I did mention this in closing: "can also make one revenue."