In general fossil fuels have capacity factors around .55, nuclear about .9, hydro about .4, and solar is between .1-.3
So you can imagine a scenario where we have 200MW of natural gas and 200MW of solar, and a grid load of 300MW. The natural gas could produce 400MW, powering the grid alone. Similarly, we could have up to 1 GW of solar, more than enough. But the averages are what is important, and what we use in ratings.
These stories are mostly “feel good” and without meaning imo. We will hit 100% energy from renewables for x minutes, long before we have enough power for the grid. If we were trying to make all the renewables come online at once, you don’t actually need that much capacity to hit 100%. The capacity factor says we only need 1/5 of the grid as solar to hit “100%” renewables. The reason we haven’t is intentional, we want more consistent power from these typically inconsistent renewable sources.
average power = capacity factor * max power
Thus it is clear why nuclear is .9, it doesn’t vary much in its generation. The max is only a bit more than the average. Capacity factor is in some sense, but not exactly, the variability.
Even if California made it the final 3% to reach 100% renewable energy (by the headline metric), it will still depend on a significant amount of non-renewable energy for significant parts of every single day (or else it will have blackouts).
It's not like you can ramp a coal-fired or nuclear power station up and down on a whim either though. It takes time and planning to modify the output if you don't have storage capacity. Power companies do a lot of predictive analysis to forecast demand and make sure they're running a little ahead. Here in the UK we even have a term called "TV pickup" where the electricity demand for the country increases significantly immediately after popular TV shows when we all go and put our kettles on for another cup of tea[1].
Power demand varies a lot, and in a reasonably predictable way, so you're fine so long as you have a mix of generation technologies. For most places that'll end up being solar, wind and nuclear, with extensive storage capacity.
At least nuclear you can relatively fast. In terms of KW/min change rate faster then most gas peaker plants. It is not done much outside of France though as the operating costs of a nuclear power plant are pretty much identical when operating at 5% or 100% output.
edit:
German nuclear power plants also used to do load matching.
https://www.oecd-nea.org/upload/docs/application/pdf/2021-12...
Source for the KW/min change rate of nuclear vs CCGT/coal
https://snetp.eu/wp-content/uploads/2020/05/SNETP-Factsheet-...
Those types of real time viewing figures are limited to live England matches in the euros/World Cup, and very unusual events like the PM’s covid broadcast back in 2020
I’m surprised the US doesn’t have the phenomenon during the super bowl. I guess the lack of kettles and the main attraction of the Super Bowl being the adverts dampens it down though.
You can with nuclear: thermally it is kept running, but the steam bypasses the generators and so there is no electrical production.
"97% of some state's energy production was renewable" doesn't tell you much, because they could be a state that hardly burns any fossil fuels.
"California managed to produce enough renewable energy to power 97% of the needs of a state the size of California" actually tells you how much renewable energy it generated, and why that's a big deal.
If yes, I think the math is misleading.
It doesn't matter if you generate 97% from renewables if you can't trust it and still need to keep dirty sources, even during renewable peak...
Hilarious, how to lie with statistics 101.
The only critique I’ll say though is nuclear is definitely clean energy.
As for “at night”, it is possible to get batteries of household scale. Plus insulation is getting better and cheaper, so the power required to maintain any given temperature isn’t as high as it used to be.
At times of the year when there are blizzards, I seriously doubt the rest of solar installations in the US are going to be running anywhere near capacity.
Second: My first visit to the USA, I saw people surfing in Asilomar on Christmas Day/Boxing Day and it remained warm and sunny throughout my stay in California, yet a few days into that trip New York was suffering a blizzard that Trump was trying to argue disproved global warming: https://en.wikipedia.org/wiki/Early_2014_North_American_cold...
You're assuming they have an infinite lifespan. They don't.
That being said, it might still be a good signal that investments in renewable electricity infrastructure could be accumulating up to critical mass in some areas. And that is encouraging.
Source: https://www.caiso.com/TodaysOutlook/Pages/supply.html