Anytime the sun is out, your own home's roof is subjected to power from the sun. Why don't you harness that energy, decrease your electricity bill as well as decrease the amount of carbon dioxide you add to the ecosystem day after day? Depending on were you reside, your roof top's direction, plus the load your home's roof will be able to bear, installing photovoltaic cells (PVs) on the roof might be a valuable investment in boosting your home's energy...