Explore the Solar Systems
Live off the grid with solar panels and green energy
Photovoltaic (PV) Systems
Solar electric systems, also known as photovoltaic (PV) systems, capture sunlight and convert it into electricity for use in homes and businesses. PV systems allow homeowners to produce the energy needed to power all or some of their home from a clean, renewable source -- the sun.
While PV systems are capable of powering houses and small businesses without any connection to the electricity grid, many prefer the advantages that grid-connection offers. This is because any excess electricity you produce is fed back into the grid. When you need it, electricity from the grid supplies your needs, thus eliminating the expense of electricity storage devices like batteries.
Federal law requires the local utility to buy PV-generated electricity from homeowners. The rate paid for the electricity depends on the utility company. That means that depending on your energy consumption and solar panel return, your utility company might have to pay you. Now that's a bill that's easy to live with!
Solar cells. These are the basic building blocks of the system. They're made of crystalline semiconductor materials, the most popular being silicon. Solar cells are combined to form solar panels that output 10 to 300 watts of electricity. Several panels can be combined to form an array positioned on or near the home. Ten to 20 arrays can provide enough power for a typical household.
Thin-film photovoltaic (PV) cells that double as roof shingles are also available. The lightweight, easy-install shingles look like traditional asphalt shingles, but they collect solar power as they guard the roof.
Inverter. An inverter converts direct current (DC) electricity produced by solar cells to alternating current (AC) electricity required to run household appliances. Additional conditioning equipment is needed to ensure that the quality of electricity produced meets the load requirements and utility company standards.
Meter. A meter allows homeowners to monitor the amount of power being consumed. If the utility company offers net metering, the meter can also be used to record excess electricity the PV system feeds back into the grid. In this case, the meter spins forward when electricity is being drawn and backward when electricity is being produced. Utilities that don't offer net metering require homeowners to install a second meter to track the electricity the PV system feeds into the grid.
While PV systems are capable of powering houses and small businesses without any connection to the electricity grid, many people prefer the advantages that grid-connection offers. This is because any excess electricity you produce is fed back into the grid. When you need it, electricity from the grid supplies your needs, thus eliminating the expense of electricity storage devices like batteries.
Off-grid PV systems require additional components including batteries to store power for use when the system isn't producing electricity; charge controllers to regulate the electricity flowing from the generation source into the load or batteries; and safety features such as safety disconnects, grounding equipment and surge protectors.
The cost of a PV system depends on the size of the system. It has high upfront costs, but homeowners can benefit over the life of the system by reduced monthly electricity costs. A small, single-PV-panel system that produces 75 watts costs about $900 installed, however, this size of system will cover a fraction of a typical home's electricity needs. Mid-range, a 2-kilowatt system that meets nearly all the needs of an energy-efficient home could cost $16,000 to $20,000 installed. On the high end, a 5-kilowatt system that completely meets the energy needs of many conventional homes can cost $30,000 to $40,000 installed.
Finally, regulations and permitting for a PV system vary widely. The system supplier or installer should know the requirements of the local community and utility company.