Electricity produced from wind rose 13% in 2013 to 36.9 million MWh from a year earlier followed by landfill gas, hydro, biomass and solar, according to a report by the Electric Reliability Council of Texas (ERCOT), which manages about 85% of the state’s electric load.

Generators reporting participate in the Texas renewable energy credit (REC) trading program. A REC is a tradable instrument that represents one MWh of renewable energy produced.