CHICAGO — A law originally enacted to keep the state’s nuclear fleet profitable is instead giving relief to energy customers due to rising power costs and increased federal subsidies for nuclear generators. ComEd customers in Illinois will see an average $19 monthly reduction to their electricity bills over the coming months, thanks to a policy in the state’s landmark climate bill.

Even as solar projects have boomed in Illinois in recent years, the head of the state agency responsible for approving renewable projects said changes to state law may be necessary to phase out fossil fuels by 2050.

By 2025, at least 25% of the Illinois’ energy must come from renewable sources, like wind or solar. But projections by the Illinois Power Agency find that without changes to current policy, the state could fall short.