TechnicalUp to date · Jan 15, 2026
NREL (National Renewable Energy Laboratory)
The U.S. Department of Energy's primary laboratory for renewable energy and energy efficiency research. Located in Golden, Colorado. Provides definitive data on solar resource, costs, and technology.
Why It Matters
NREL's PVWatts calculator and annual technology baseline reports are widely used to estimate solar production and costs. Their data backs most solar savings calculators.
Related Terms
Irradiance
The power of solar radiation received per unit area, measured in W/m² (watts per square meter). Standard peak irradiance at earth's surface is ~1,000 W/m² under clear skies at solar noon.
Peak Sun Hours
The equivalent number of hours per day when solar irradiance averages 1,000 watts per square meter. Varies by location.