California Moves to Expand Landmark Solar Mandate Beyond Houses

California regulators approved a plan to expand the state’s landmark rule requiring solar panels on newly built homes to include apartments and commercial buildings, taking another sweeping step away from fossil fuels.

The rule passed Wednesday by the state’s Energy Commission will take effect in January 2023 if also approved by the California Building Standards Commission.

The move builds on California’s 2020 mandate for panels on almost all new homes, the first such policy in the U.S. The rule also requires that new single-family homes include wiring to support battery systems and includes incentives for appliances that don’t use natural ...