CAISO Solar captured -$1.7/MWh in spring 2026
Between March and May 2026, CAISO solar captured a generation-weighted average price of -$1.7/MWh.
A negative capture price means solar, on balance, lost revenue in the wholesale market across the season.
A note on methodology - and why solar would choose to lose wholesale revenue
Capture prices are the generation-weighted average price that solar sites receive per unit of energy sold to the wholesale market.
This article estimates solar capture prices by scaling zonal generation profiles to each site’s rated power. This creates estimated site-level solar generation profiles.
These estimated site-level profiles are multiplied by the Day-Ahead price at seen at each site, and divided by total generation, to calculate the average capture price.
Capture rates are the ratio between this solar capture price and the average nodal price, known as the around-the-clock (ATC) price. This ATC is what a baseload generator would receive for producing 24/7.
These metrics only capture wholesale market activity. They do not account for out-of-market revenues, such as PPAs or Federal Tax Credits, that these sites likely receive.
Incentive payments drive solar to continue exporting to the market even when it is uneconomical to do so.
Capture rates dipped to -38% in April 2026, leading spring to settle at an average of -13%. This is a decline from Spring 2025’s average capture rate of +1.2%.
Spring is consistently the weakest season for solar wholesale revenue in CAISO.
Heating and cooling load vanishes in response to milder weather, while daylight hours extend and lift solar output. Midday supply runs well ahead of demand. The result is that, year over year, Californian power prices regularly dip below zero throughout the season.
Negative prices grow shallower as Solar raised its offer floors
Five months into 2026, CAISO has logged 516 hours of negative Day-Ahead prices. While this surpasses 2025, the magnitude of these negative prices has grown shallower.
Average negative prices in spring 2026 settled at −$5.5/MWh, compared to −$9.8/MWh in 2025 and −$14.6 in 2024. The magnitude of negative pricing has roughly halved each year.
Sign up to read this article for free
Unlimited access to our free articles
Monthly access to 3 Global Research articles
Benchmarks, Forecasts, Ko and more
