The intense wildfires that ravaged California in the US in 2020 were responsible for substantial solar energy forecast errors, according to a study led by scientists at the National Center for Atmospheric Research (NCAR).

The smoke darkened so much the skies in California that it slashed the state’s solar power production during peak hours between 10-30% in comparison with similar days in previous years.

Solar energy production averaged 27% less than forecast and even dipped to as much as 50% less than forecast during late afternoon and early evening hours when it coincided with a ramp-up of energy demand.


The study used data gathered from the California Independent System Operator (CAISO) and was focused on the period from 7 to 16 September 2020, when the fires were peaking in the US state. During the studied period, when smoke activity in the air was increased, CAISO did not include the effects of smoke in its hour-ahead forecast and ended up overestimating the expected power production by 10% to 50%.

As events such as the 2020 California wildfires might become more frequent in the coming years – half of the ten largest wildfires that occurred in California’s history happened during that season in 2020 – including the effects of smoke on solar energy forecasts should be recommended to reduce errors in forecasting solar power estimates.

Read more: PV-Tech

It’s Time to Go Green!

If you would like to know more about Solar Panels and the PowerBanx range of home battery systems, and get a free instant quote, please complete our online form: