Definition
The amount of solar radiation reaching a given area, measured in watts per square meter (W/m2). Standard Test Conditions (STC) use 1,000 W/m2 as the baseline for panel ratings. Actual irradiance varies by location, time of day, season, and weather.
Related Solar Terms
- Photovoltaic (PV)
The technology that converts sunlight directly into electricity using semiconduc...
- Kilowatt (kW)
A unit of electrical power equal to 1,000 watts. Residential solar systems are t...
- Kilowatt-Hour (kWh)
A unit of electrical energy equal to one kilowatt of power sustained for one hou...
- Net Metering
A billing arrangement where excess solar electricity sent to the grid earns cred...
- Inverter
A device that converts the DC (direct current) electricity produced by solar pan...
Understanding solar terminology helps you communicate more effectively with installers and evaluate quotes accurately. Use our solar cost database to find fair prices for any solar service.