First-hand experience: our solar installation has a monitoring thingy that tells us how much electricity we've used from it and the grid. Over the past month (low-sun November) it's 25% from solar 75% from the grid. To me, that's as clear as it gets, even if at certain hours of the sunny days we get 100% powered by the panels. It can only ever be a supplementary source of energy.
Yeah, and that's the challenge in trying to illustrate nameplate capacity of a solar or wind project. It's always supplementary. It's like trying to explain how many people will be fed by a dietary supplement.
Our November in Oregon was cloudy and rainy all month, on top of the days getting shorter. Our solar panels only put out about 10% of their rated power.
Arguably, you could simply divide the number by 2 since you always need the equal amount of on-demand power when solar or wind aren't producing. so, at most, that 100 MW solar farm, which has a 22,5% efficiency really only has half as much on a cost basis since it costs again to have the natgas plant to be there when the sun sets.
It is not only the “number of homes powered” metric that energy reporters, and investor owned utilities, use to fool the public, but also their misleading claims that a given grid is supplied by 100% renewable energy.
Fabulous take! I loved the offshore wind rating in whales. Onshore wind and solar concentrators should be similarly rated in birds. Solar PV would be rated in food not grown.
TY for the article. The other constant misleading thing regarding "this project will power xx,xxx number of homes" is that the Solar PPA Offtaker gets first dibs on all the power - AI Data centers from say Amazon, META, etc... It is so irritatingly purposely misleading to the public.
Getting rid of oil, coal, and gas and spending money on wind mills and solar panels is like a business letting go of all its employees and replacing them with part time employees that will show up for work when they want and for how long they want.
Nerd level detail: Half time is almost perfectly accurate, averaged over the year, at every point on Earth. It would be perfectly half time if the orbit of the Earth around the Sun were circular. Since the orbit is slightly elliptical, some higher latitudes will see the Sun slightly more or less than half the time.
Sure but that was not my point. Trying to explain capacity factor is much more complex than just pointing out that solar cannot provide any power at all half the time on average. Al was looking for simple and effective ways to make the point.
Oh, I see your point. And also, as I mentioned in the article, what time of day the generator is producing matters. If your solar output falls on a hot summer evening as the sun sets, you have no power when you need it the most.
Great point - "The total number of homes that can be powered by any wind or solar project regardless of its size is 0.0. It doesn’t matter if the project’s capacity is 2 gigawatts or 1 megawatt, it is always precisely zero." Certainly true for grid projects.
Residential rooftop solar could be an exception IF the homeowner wants to install a lot more panels than thought needed, and a huge battery backup system, but of course that would probably bankrupt the average homeowner.
It would also require more space than their rooftop. It is possible, according to my back-of-the-napkin calculations, to design a solar-battery system that can power a home, with 3 days backup. You need some acreage for the panels, and several Tesla Powerwalls costing $10,000 each, and you have to replace them every 10 years. And with only 3 days, you're likely to have some blackouts. So, yes, if you're rich but still live in an average-size home, it can be done.
First-hand experience: our solar installation has a monitoring thingy that tells us how much electricity we've used from it and the grid. Over the past month (low-sun November) it's 25% from solar 75% from the grid. To me, that's as clear as it gets, even if at certain hours of the sunny days we get 100% powered by the panels. It can only ever be a supplementary source of energy.
Yeah, and that's the challenge in trying to illustrate nameplate capacity of a solar or wind project. It's always supplementary. It's like trying to explain how many people will be fed by a dietary supplement.
Exactly. Perfect analogy.
Our November in Oregon was cloudy and rainy all month, on top of the days getting shorter. Our solar panels only put out about 10% of their rated power.
Arguably, you could simply divide the number by 2 since you always need the equal amount of on-demand power when solar or wind aren't producing. so, at most, that 100 MW solar farm, which has a 22,5% efficiency really only has half as much on a cost basis since it costs again to have the natgas plant to be there when the sun sets.
Excellent information.
It is not only the “number of homes powered” metric that energy reporters, and investor owned utilities, use to fool the public, but also their misleading claims that a given grid is supplied by 100% renewable energy.
Fabulous take! I loved the offshore wind rating in whales. Onshore wind and solar concentrators should be similarly rated in birds. Solar PV would be rated in food not grown.
One thing makes this kind of misleading reporting even worse: It neglects to mention the strain on the grid from excessive supply exceeding demand.
TY for the article. The other constant misleading thing regarding "this project will power xx,xxx number of homes" is that the Solar PPA Offtaker gets first dibs on all the power - AI Data centers from say Amazon, META, etc... It is so irritatingly purposely misleading to the public.
Getting rid of oil, coal, and gas and spending money on wind mills and solar panels is like a business letting go of all its employees and replacing them with part time employees that will show up for work when they want and for how long they want.
Sounds pretty stupid, no?
I'm not sure that nameplate capacity is the thing to address first. Start with solar cannot provide any power at all half the time on average.
Even at the equator! 12 hours of daylight year round - no seasons - but that's still only half a day, so your point is true everywhere in the world.
Nerd level detail: Half time is almost perfectly accurate, averaged over the year, at every point on Earth. It would be perfectly half time if the orbit of the Earth around the Sun were circular. Since the orbit is slightly elliptical, some higher latitudes will see the Sun slightly more or less than half the time.
Solar's capacity factor varies greatly by location -- from as little as 16.5% in New England to as high as 28.4% in California.
https://www.eia.gov/todayinenergy/detail.php?id=39832
Sure but that was not my point. Trying to explain capacity factor is much more complex than just pointing out that solar cannot provide any power at all half the time on average. Al was looking for simple and effective ways to make the point.
Oh, I see your point. And also, as I mentioned in the article, what time of day the generator is producing matters. If your solar output falls on a hot summer evening as the sun sets, you have no power when you need it the most.
Great point - "The total number of homes that can be powered by any wind or solar project regardless of its size is 0.0. It doesn’t matter if the project’s capacity is 2 gigawatts or 1 megawatt, it is always precisely zero." Certainly true for grid projects.
Residential rooftop solar could be an exception IF the homeowner wants to install a lot more panels than thought needed, and a huge battery backup system, but of course that would probably bankrupt the average homeowner.
It would also require more space than their rooftop. It is possible, according to my back-of-the-napkin calculations, to design a solar-battery system that can power a home, with 3 days backup. You need some acreage for the panels, and several Tesla Powerwalls costing $10,000 each, and you have to replace them every 10 years. And with only 3 days, you're likely to have some blackouts. So, yes, if you're rich but still live in an average-size home, it can be done.
You pretty well nailed it, Kevin.