Photovoltaic panels are a clean way of generating energy for the household… Photo: solar-calculator.org
Solar Energy: Demand Grows
When photovoltaics (PV) or the conversion of solar energy to electric power came on the scene 30 years ago, it was so inefficient that few thought it could ever power American homes. But the technology has come a long way, and demand for PV systems in the U.S. is now growing at almost 25 percent per year.
- In sunny California, brownouts and energy crises have pushed the state to set an ambitious goal of putting photovoltaic systems on a million roofs by 2016.
Government Incentives Reduce Costs
The cost of installation can be daunting for homeowners, but government incentives make them much more enticing.
- The federal government rebates $2,000 per system.
- In California, the state not only gives a property tax reduction for the cost of the system, it also rebates $2.50 for every system watt. So, a 4-kilowatt system that costs $36,000 only winds up costing the homeowner $26,000.
- In Florida, homeowners can get $4 per system watt, so the same system costs only $18,000. Add to that the value of the electricity generated by the system - which, depending on your area, can be between $250 and $750 per year - and photovoltaics start to make a lot more sense.
Solar Energy: How it Works
As roof-mounted panels or even integrated into asphalt roof shingles, photovoltaic cells contain silicon wafers which react to sunlight by releasing free electrons. These electrons create direct electric current, or D/C power. The system's inverter switches the D/C to the alternating current, or A/C, that powers our homes.
Household photovoltaic systems have become simpler and better adapted to mainstream use now that grid-tied net metering is easier and no battery backup is needed. Any electricity the system generates that's not used in the home gets sold directly back to the power company.
The Wave of the Future
In sunny areas, the larger 4-kilowatt systems available today can generate half or more of what the average household consumes. Even where it's not so sunny, photovoltaic systems have become so viable that many forward-thinking developers are pairing them with geothermal heat systems to market the new non-polluting, low-energy home.