Musk, Movie Stars Join Fight to Protect California Solar Subsidy

Hollywood celebrities, billionaire Elon Musk and even basketball legend Bill Walton are all lending their star power to oppose a California proposal that would cut subsidies for rooftop solar systems.

Actors Edward Norton and Mark Ruffalo, as well as Musk, who runs electric car maker and solar provider Tesla Inc., all took to Twitter this week to slam a plan by the state’s regulators that would impose new fees and reduce payments to residents who install rooftop solar.

“We need to get loud on this,” Norton— who starred in “Fight Club”— said in a Twitter post. “This is truly a moment of ...