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Satellite powered estimation of global solar potential

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Re: Satellite powered estimation of global solar potential

#61

Post by tppiotrowski »

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. :(

Re: Satellite powered estimation of global solar potential

#62

Post by prdonahue »

buckle8017 wrote: post #50

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.

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.

Re: Satellite powered estimation of global solar potential

#63

Post by buckle8017 »

stainablesteel wrote: post #52
buckle8017 wrote: post #50

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.

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

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

Re: Satellite powered estimation of global solar potential

#64

Post by yongjik »

xnx wrote: post #12

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 t…

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.)

Re: Satellite powered estimation of global solar potential

#65

Post by wongarsu »

Glyptodon wrote: post #59
xnx wrote: post #12

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 t…

At a certain point shouldn't things get good enough you don't really need a traditional power grid?

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.

Re: Satellite powered estimation of global solar potential

#66

Post by ggreer »

buckle8017 wrote: post #50

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.

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...

Re: Satellite powered estimation of global solar potential

#68

Post by szvsw »

yongjik wrote: post #64
xnx wrote: post #12

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 t…

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.)

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.

Re: Satellite powered estimation of global solar potential

#69

Post by wongarsu »

jeffbee wrote: post #6

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" everyw…

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.

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