The biggest pain in the ass of a generation project and the thing slowing everything down is the interconnection queue and the cost of transmission system upgrades So the easiest thing to do is stick panels next to a dead coal plant and use their existing interconnection facilities and capacity
Minnesota just plugged a 710-megawatt #solar farm into a coal plant that once burned 30,000 tons a day. The unique approach to connecting the panels to the grid allowed it to sidestep a typically years-long connection process.