interesting comments. i've always assumed that you would be able sell the power generated at market price. but that price will be driven down when more people install similar power-generating equipment. i've been similarly thinking about social eco-friendly ideas... but in the carbon tax arena. i recently read an article about private jets charging the super rich a percentage of the fare to offset their carbon-emissions. on its own, it won't matter much, but i wonder to what degree can it be stretched to make carbon taxing a real solution.