There is a lot of discussion today about alternative energy sources as the price of oil and gas has risen at a high rate recently, and liberal politicians are attempting to stop use of fossil fuels. One of the alternative sources that could be used on an individual level is photovoltaic cells. If the price of the solar cells were low enough the the cells could be installed on rooftops and used to produce power when the sun is shining. It would also be possible to install batteries that would store energy for use while the sun is not shining, though this would add a lot to the costs. The solar cells generate low voltage direct current so the power must be put through an inverter to convert it to alternating current, and through a transformer to increase the voltage level to 110 or 220 volts. Solid state electronics make these steps relatively easy to accomplish, but there is still considerable expense involved. Such a system would need over 10,000 watt capacity for a typical house in Ft. Worth. (The solar cells produce 5 or 6 Watt per square foot, so about 2000 square foot of roof area would be required.) If the solar cells cost $2/watt, the solar cells would cost $20,000. The total installation might cost $35,000. Conventional fuel will have to be a lot more expensive to make this economically attractive. There is a lot of work being done on low-cost solar cell production. Here is a paper discussing some of the work being done in the quest to get solar cell cost down to $1 per watt.

http://spectrum.ieee.org/aug08/6464/4