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Satellite powered estimation of global solar potential

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Re: Satellite powered estimation of global solar potential

#42
post #14

Earlier quoted context omitted.

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.

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.

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.

Re: Satellite powered estimation of global solar potential

#43
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…

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.

Re: Satellite powered estimation of global solar potential

#44
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…

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.

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.

Re: Satellite powered estimation of global solar potential

#45
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.

Re: Satellite powered estimation of global solar potential

#46
post #7

Earlier quoted context omitted.

> 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.

Joules is the solution to both the problems (the second is that Wh for energy is as silly as speed hours for distance)

Watt-hours is a perfectly pragmatic unit. Measure instantaneous power and multiply by a common human unit of time. It's easy to compare.

Re: Satellite powered estimation of global solar potential

#47
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…

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....

Re: Satellite powered estimation of global solar potential

#48
post #44

Earlier quoted context omitted.

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.

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.

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.

Re: Satellite powered estimation of global solar potential

#49
post #5

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…

> 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?"

In that specific case, I chose megameters.
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