California’s ambitious clean energy polices are not to blame for rolling blackouts during a scorching heat wave this month, but more work needs to be done to integrate large amounts of wind and solar energy, the state’s energy agencies said on Wednesday.

“Our organizations want to be clear about one factor that did not cause the rotating outage: California’s commitment to clean energy,” the heads of the agencies said in a letter to Governor Gavin Newsom.

“Clean energy and reliable energy are not contradictory goals.”

The heads of several state power bodies and commissions said they would analyze power outages for about 400,000 households on Friday and Saturday, including whether demand forecasts need to account for more heat waves due to climate change.

California has among the most aggressive policies to combat climate change in the nation, including a goal of sourcing 60% of its power from renewable sources by 2030. This is being closely watched by other governments as they craft their own energy policies.

Some critics have blamed the state’s clean energy mandate as causing the power shortages, including President Donald Trump who tweeted on Tuesday that California had “failed policies.”

“We clearly need to do more” to accommodate the wind and solar resources that made up about 20% of power generated in the state last year, the agencies said.

Specifically, they said they would look at utility procurement plans and refine demand forecasts. Just last year, the California Public Utilities Commission ordered 3,300 megawatts of capacity to come online by 2023 because of reliability concerns.

Guest post from Reuters