How Photovoltaic Systems Work
There are three basic types of solar energy systems available for residential and commercial use: (1) Grid-tie (2) Grid-tie with Backup and (3) Off-grid.
All use solar photovoltaic (PV) panels and are typically installed on the south facing roof of your structure. These panels power the system, producing DC (direct current) electricity when the sun is available. (If roof space is restricted or compromised, we can offer alternative solutions.)
Grid-tie or grid-connected systems make up most of solar energy systems in use. With Grid-tie systems, the DC electricity generated by the PV panels passes through wiring on the roof, down to an inverter mounted on the house.
The inverter converts the DC electricity to AC (alternating current) electricity that is compatible with home or office wiring and appliances. The AC power from the inverter then passes to the main electrical panel where it can supply the needs of the building.
Excess energy can generate utility credits
Typically, during sunny periods, the solar panels generate excess energy. This excess electricity passes backward through the electric meter and to your utility’s power grid.
In most cases, you will get a full or partial credit for this excess electricity applied to your electric bill. When the sun is not shining, you will use electricity from the electric utility grid as you would if you did not have a solar energy system.
A grid-tie system can be sized to meet part or all of you electricity needs. Systems that meet all of your needs will produce enough excess electricity during sunny periods to totally offset the power used when the sun is not shining.