What is a photovoltaic energy provider and how does the system work?
Photovoltaic (PV) systems produce alternative energy from the sun’s energy. The PV panels are a semiconductor material (no moving parts) that works as a generator to turn sunlight into electricity. Typical components of a system are:
- Manufactured PV modules
- Wiring that takes the produced electricity from the roof to the
- Converter, which changes the direct current (DC)
to an alternating current (AC), which is the most
common type of electricity used in homes.
The system is typically connected to your meter and can flow energy back to the grid, this rolls the meter backwards. Some PV panels are more efficient that others. On average they are 10% efficient and have a 10-25 year warranty.
In case of blackouts or continued period of no-sun days, batteries can be used to store generated electricity. You can get power on an overcast day because the photovoltaics can see light at very low levels. A partly cloudy day can provide half the energy of a sunny day.
A PV system can produce anywhere from 400 kWh /month up to 1200 kWh/month. For an average 3 bedroom home of 1,500 square feet a PV system is usually made up of 2-3kW modules. When designing your system a good rule of thumb is to have 1kW for every 100 sq ft of roof.
At this date, alternative energy sources are more expensive than traditional energy providers. A total final cost between $5,000-25,000 is expected for homeowners, however when deciding on an energy provider it is important to think about the lifecycle savings that add to the worth of the system. In the end your system costs an average $0.10-20/kWh. Current energy prices are not expected to stay this low and investing in an alternate energy system will save you money down the road.
Barbara Buffaloe, Architectural Studies, College of Human Environmental Studies, University of Missouri-Columbia
Last update: Monday, May 18, 2009