Comment by gwright
1 year ago
Why do you think that can't be right?
Solar and wind generation themselves are seasonal and don't match the seasonal patterns of demand. So you need to time shift across seasons if you don't have the instantaneous (base load) capacity available all the time.
You might say, well, just build more windmills or solar farms. Doesn't help when it is dark and calm. Your "overbuild" is useless in that situation. So you need storage (or other base load generation, fossil or nuclear).
In this study, it is estimated that Germany and California both need about 25TWh of storage to time shift energy supplied by intermittent sources to other parts of the year. The study claims $5 trillion to purchase batteries to store that much energy.
http://euanmearns.com/the-cost-of-wind-solar-power-batteries...
You're kind of making OPs point though - that post was written by a retired 80yr oil engineer who just blogs into the aether because he hates solar and wind.. the $5 trillion estimate was him literally just making up numbers.
To critique this more specifically - in that post he assumed we would spend $5 trillion on batteries, and they would still cost the same $200/kwh that they cost in back in 2018. Even if his other assumptions on the capacity required were valid (they aren't), costs have already fallen below $100/kwh since learning curves exist - so his scary $5 trillion number is already below $2.5 trillion. Add in the additional cost savings and amortize that investment over a decade and you're talking about maybe 3.5% of the Federal budget?
No, you just need peaker plants which can run for the 1-3 weeks per year when there is no wind in the winter.
Battery capacity will never be built to exceed 1-3 days of demand.
And because they are run so infrequently, they don't need to be fancy or efficient - just cheap and powerful. It's easier than one might imagine, but it helps if you think of scale along the lines that horsepower is roughly comparable to kilowatts, so a 200 horsepower car engine (which is small) can provide 147kW, or enough power to supply around 147 houses on average (depending on a lot of things obviously - in a climate with high heating/cooling demand it won't manage as many houses). It's not uncommon to have single diesel generators capable of generating 4MW of electricity running around on train tracks.
So you need to have two generation systems. Certainly possible, not cheap.
I assume in this conversation that we want:
If you relax those assumptions you open up the solution space. It isn't clear to me how much you can relax those assumptions though.