SAN FRANCISCO (AP) — A cycle of extreme heat, drought and wildfires is threatening California's power supply.

In the past two years, windstorms led utilities to deliberately shut off power to wide swaths of the state to lower the risk of power lines igniting wildfires. The state last summer ran out of energy when an oppressive heat wave triggered the first rolling blackout in 20 years.

To improve energy resilience, utilities and small communities are installing microgrids that can disconnect from the larger electrical grid and switch to using solar energy generated and stored locally.

Other tactics include increased electricity costs during high-demand hours and energy conservation incentives when the grid is strained.