Solar energy converts sunlight into electricity using photovoltaic (PV) cells or concentrated solar power (CSP) systems. Utility-scale solar farms and rooftop solar installations have both grown rapidly as panel costs have fallen over 90% since 2010. Solar capacity factors range from 15-30% depending on location, with the Southwest US having the best solar resources. Solar now accounts for about 5% of US electricity generation and is the fastest-growing energy source.
Solar Energy
Electricity generated from sunlight using photovoltaic panels or concentrated solar power systems.
Reviewed by EnergyProfile Editorial Team · Updated
Related Terms
Renewable Energy
Electricity generated from naturally replenishing sources: wind, solar, hydro, geothermal, and biomass.
Net Metering
A billing arrangement where solar panel owners receive credit for excess electricity they send back to the grid.
Capacity Factor
The ratio of actual electricity output to maximum possible output over a period, measuring plant efficiency.
Solar Energy is one of the U.S. state-level electricity rates and generation mix concepts that recurs across this site. The definition above is the technical answer; the paragraphs below add the practical context for how the concept connects to the the EIA Open Data API and State Electricity Profiles data behind every per-entity page on the site.
In the the EIA Open Data API and State Electricity Profiles data, this concept shapes one or more of the fields that drive the per-entity grades and rankings on this site. The methodology page describes which fields feed into which output; this glossary entry documents the underlying term.
Source: U.S. Energy Information Administration, 2026.