Makes complete financial sense for US as a whole, just not for individuals. So the answer is for the US as a whole to make it worthwhile and do both nation and citizens a lot of good. US oil imports ($500B per year) and US military spending ($500B for the oil wars portion) are costing US $1T a year, $15T in oil trade deficit taxes and $14T in US oil war debt over last 30 years. Take that $1T per year we waste on oil imports and oil wars, apply it to each US home providing solar hot water and solar electric panels, it would cut US energy us by 20-30% for the one year's cost of trade deficit and oil wars. That's a one year payback nationally vs. a 20 year pay back individually.