This API provides data on U.S. electricity generation by fuel type, i.e., coal, petroleum, natural gas, nuclear, hydroelectric, wind, solar, geothermal, and wood. Data also organized by sector, i.e., electric power, electric utility, commerical and industrial. Annual, quarterly, and monthly data available. Based on Form EIA-906, Form EIA-920, and Form EIA-923 data. Users of the EIA API are required to obtain an API Key via this registration form: http://www.eia.gov/beta/api/register.cfm