Why Illinois has struggled to turn old coal sites into solar farms

Illinois launched a program five years ago to turn old coal plant sites into solar farms and battery storage, hoping to reuse existing grid connections and offset local tax and job losses from coal closures. The plan called for at least six solar-plus-storage sites and five stand-alone battery banks. Instead, only three relatively small solar-plus-storage projects got built, and no stand-alone battery banks.

A new report from the University of Illinois' Climate Jobs Institute and the nonprofit Prairie Rivers Network found the incentives were too weak once inflation, supply-chain problems, and higher borrowing costs made projects more expensive. The state had set a fixed price of $30 per renewable energy credit, and companies could only claim credits if they added several megawatts of battery storage. When costs rose, developer Vistra built only the minimum battery size required and shrank its planned solar capacity by nearly half. Other coal-plant owner NRG dropped its projects entirely. The report also pointed to toxic coal ash on many sites, which blocked development, and noted that solar farms bring far fewer jobs and less tax revenue than the coal plants they replace.

None of this involves a program homeowners can apply to — it's about utility-scale sites, not home upgrades. But it shows that clean-energy incentives only work if they're priced to keep up with real costs, a lesson state officials say they're applying to Illinois' newer battery storage law, which offers flexible pricing and aims to add 3 gigawatts of storage to the grid by 2030.