I wonder why we're not seeing such precipitous drops in the cost of personal solar installations? It still takes a couple of decades for a home panel installat

I wonder why we're not seeing such precipitous drops in the cost of personal solar installations? It still takes a couple of decades for a home panel installation to pay for itself, and that's if you're in a good area for sunlight. Regardless, it's excellent news. Coal is godawful stuff and we'll be much better off leaving it in the ground where it belongs.