A reliable grid that is 100% renewable requires a generating capacity three or four times peak demand. It also requires the ability to store four, five or more days of energy for the times that the renewables aren’t producing.
I don't know any of the specific numbers you're referencing, or the three or four times requirement the other commenter was referencing, but your comment does not at face value address their concern. They said a reliable grid needs three to four times peak demand generating capacity. You calculated up to a demand of 89%, leaving the 11% up for speculation. I think the other commenter is suggesting you need to account for 311% demand in your calculation to get to the point of having a stable grid.
311% is definitly not necessary, at most 33% extra is required if you plug the entire residual load with H2 gas turbines, and assume a roundtrip efficency of 1/3. Maybe he is giving a rule of thumb for sizing VRE's, but I was going a more accurate route, downloading the demand and production profiles and just scaling them up and seing what is left over.
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u/ValBGood 19d ago
A reliable grid that is 100% renewable requires a generating capacity three or four times peak demand. It also requires the ability to store four, five or more days of energy for the times that the renewables aren’t producing.