In the US, at least, fossil fuel costs are still so low that solar or wind energy approaches aren't economically feasible---unless they're subsidised by the government.
In New Jersey, f'rinstance, about half the cost of a photovoltaic installation is provided by the state government, and the local power companies (who don't want to have to build more generating capacity) have agreed to buy any excess generated at the current maeket price. This provides a roughly 9-10 year payback, which would be drastically reduced if fuel prices rose during that period.

Heat pump water heaters work, but they draw their heat from air which may have to be heated by other, less efficient means. Ground- or water-sourced heat pumps are an excellent solution if a)you live in a temperate climate and b) if you can live with a rather high initial cost. one of their major benefits is the low operating cost for either heating or cooling.