You can see an example of this with Germany and a comparison of 2012 and 2020 - https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewables_need_flexible_bac

You can see an example of this with Germany and a comparison of 2012 and 2020 - https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewables_need_flexible_backup_not_baseload.png https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewabl... In 2012, nuclear was a fairly consistent... eyeballing it at 10% of the load. With 2020 there's no nuclear and pumped storage becomes the flexible load while solar has a much larger portion of the total load. If 2020 had the base load generation from nuclear, that sunny Sunday would have caused some problems. And an old article about wind and hydro and managing that energy balance on the Columbia River - https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-stakes-math-behind-the-wests-greatest-river/?sh=13563084222b https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-s... > The enormous supply of hydroelectricity during spring runoff can push electricity prices to zero—the BPA gives away electricity to local utilities for free when it’s forced to produce more than it wants to. Since wind producers enjoy production subsidies, they can push rates below zero, effectively paying other utilities to switch off their generators. Last winter, the BPA told wind producers under its balancing authority that it wouldn’t pay negative rates to them during high-water events. (In this example, they could put more water over the spillway to reduce the power generation so that wind wouldn't have to idle... but that would have meant mixing more air in the water and that can suffocate the fish and impact the salmon fishery in Oregon - https://www.oregon.gov/deq/wq/tmdls/pages/tmdls-columbia-river.aspx https://www.oregon.gov/deq/wq/tmdls/pages/tmdls-columbia-riv... and https://apps.ecology.wa.gov/publications/documents/0203004.pdf https://apps.ecology.wa.gov/publications/documents/0203004.p... pages 13-15)