This data-file tabulates the ‘decline rates’ of 3,200 US solar power plants, which have reported data to the US EIA, using in-house web-scraping and aggregation software.
Across the entire data-set, we find solar assets take one year to ramp up. Generation peaks in year 2. It then declines smoothly at 2.5% per year.
The ‘Conclusions’ tab explores the consequences. US solar generation profiles are not dissimilar from well-managed oil and gas fields; some projects may suffer 4% lower IRRs versus forecasts if they have not factored in declines; and declines will also become more material over time, slowing the ascent of solar’s share in the power mix (chart below).