Wind and solar peak at 50-55% of power grids, without demand-shifting or storage, before their economics become overwhelmed by curtailment rates and backup costs. More in wind-heavy grids. Less in solar heavy grids. This 12-page note draws conclusions from the statistical distribution of renewables’ generation across 100,000 x 5-minute grid intervals.
Wind and solar are growing. Solar was 5% of all global electricity in 2022, and as much as 15% in leading countries; while wind was 7% of all electricity, and as much as 35% in leading countries (page 2).
Wind and solar peak? Intermittent renewables cannot ramp forever, because their generation is correlated across large areas. Eventually, grids get saturated, and further installations get curtailed (page 3).
As the basis of this analysis, we have compiled the statistical distribution of renewables’ generation across 100,000 x 5-minute grid intervals across California in 2022. Our methodology, and the reasons we like it, are summarized on pages 4-5.
When would solar peak in a solar-heavy grid, on a standalone basis? Our best estimate is at a c35-40% share, for the reasons on pages 6-7.
When would wind peak, in a wind-heavy grid, on a standalone basis? Our best estimate is at a 50-70% share, for the reasons on page 8.
When will wind and solar peak, in a renewables-heavy grid, on a combined basis? Our best estimate is 50-55%, for the reasons on page 9.
Higher or lower? Admittedly, our methodology makes some important simplifications, and further nuances are discussed on pages 10-12.
Ultimately, including demand shifting and thermal storage, we predict that wind and solar will peak at 50-70% of future renewable-heavy grids. The leading backstop, for the other 30-50%, in our view, will be natural gas, followed by nuclear and hydro.