How dumb is this? Use coal to boil water. Use steam to spin turbines and run generators to make electricity then transported long distances to connect to a coil at the bottom of a tank- to make hot water.
Solar hot water panels are dumb simple too, often just a box with a glass lid with black pipes in it; you can even build them yourself. Others, like evacuated tube collectors are more efficient if more expensive.
A solar water heater could save $ 450 a year and keep almost a ton of CO2 emissions out of the air; multiply that by 80 million houses in the USA. The technology has been around forever. Chinese manufacturers are cranking them out by the millions. So why doesn't every house have them?
evacuated tube solar hot water heater with tank
Eco-geek suggests that "First, installation can cost more than $5,000 dollars, especially in older houses. Second, new home buyers apparently don't like to see solar water heaters disrupting their "roof lines."
In other countries they are common; in some, like Israel, it's the law. Some cites encourage it; the City of Fresno provides rebates and financing. It isn't just for the sunny south, either;
Solar hot water is the cheapest and most effective active solar power system there is. It leaves fossil fuels and electricity for uses that require a higher grade of heat. Let's put it in the building codes. ::Eco-Geek