Minnesota just plugged a 710-megawatt solar farm into a coal plant that once burned 30,000 tons a day, the two sharing wires until the last boiler dies in 2030 — and one retired coal unit will keep spinning, fuel-free, to steady the solar that replaced

Minnesota just plugged a 710-megawatt solar farm into a coal plant that once burned 30,000 tons a day, the two sharing wires until the last boiler dies in 2030 — and one retired coal unit will keep spinning, fuel-free, to steady the solar that replaced it