I have calculated the contribution of real estate prices for California solar farms. The cost of land accounts for a tiny part of large scale PV electricity co

I have calculated the contribution of real estate prices for California solar farms. The cost of land accounts for a tiny part of large scale PV electricity costs -- less than 1%. But of course California is both sunnier and much less densely populated than New Jersey. Rooftop solar is not especially cost-effective. It yields less energy per installed watt than large solar farms and it costs multiple times as much per watt to install in the US. If the US could get its permitting and inspection for rooftop solar streamlined and standardized like in Germany or Australia, then the price premium over ground-mount systems would be more like 40% than 400%, and it would be worth considering in states without large open spaces. Even in Germany rooftop systems are less cost-effective than ground mount systems though the cost-effectiveness gap isn't as large as in the US. I attribute Germany's continued incentives for rooftop solar to a desire to maintain broad societal buy-in to the energy transition. Millions of households and businesses all with their own stake in solar makes for a large and stable coalition of supporters. Just having the legacy energy utilities build their own big solar plants is more cost effective but doesn't give so many people a personal stake in the transition.