Residential Solar Energy Modeling

Understanding the solar resource at your location is the first step in evaluating a rooftop solar installation. Global Horizontal Irradiance (GHI) measures the total amount of solar radiation received on a horizontal surface, combining direct sunlight and diffuse sky radiation. Higher GHI values mean more energy available for solar panels.

About the Data

This tool uses Typical Meteorological Year (TMY) data from the National Solar Radiation Database (NSRDB), maintained by NREL. TMY data represents a statistically typical year compiled from decades of satellite-derived measurements, giving a reliable baseline for solar energy estimates at any location.