Electricity generated from renewable sources accounted for more than 50% of all new U.S. energy capacity installations in 2014, growing to 15.5% of total installed capacity and 13.5% of total electricity generation.

Solar electricity installations lead the pack, increasing by more than 54% and adding 5.5 gigawatts (GW), according to a report from an annual report by the National Renewable Energy Laboratory (NREL).

NREL Renewable energy capacity growth from 2004 through 2014.

Solar electricity installations accounted for more than 48% of U.S. renewable electricity capacity added in 2014, according to NREL, part of the U.S. Department of Energy. Installed solar capacity now exceeds 179GW and generates 554 terawatt-hours of capacity.

Although solar generation still made up a small mix of the renewable electricity -- just 6% -- it accounted for 22% of total electricity capacity added in 2014.

NREL Top renewable energy installations by state.

Total solar power capacity remains well behind water-generated power. Hydroelectric made up the vast majority of renewable electricity generation in 2014, followed by wind. In 2014, U.S. hydropower produced nearly half of total renewable electricity generation, wind produced 33%, biomass produced 12%, solar photovoltaics (PV) and concentrating solar power (CSP) produced 6%, and geothermal produced 3%.

U.S. electricity capacities from biomass, geothermal and hydropower remained relatively stable between 2000 and 2014. However, generation from hydropower did drop by 3.7% last year.

NREL

U.S. wind electricity generation increased by 8.3% in 2014, growing capacity by 7.8% and 4.8GW.

Worldwide, solar photovoltaics (PV) and concentrating solar power (CSP) are among the fastest growing renewable electricity technologies. In 2014 alone, combined capacity increased by more than 28% globally, NREL said.

CSP refers to technology that focuses hundreds of solar concentrating mirrors on a water boiler, which then creates steam to turn a turbine motor.

NREL Amount of U.S. power capacity from non-renewable energy sources.

California set a record for solar power generation in March 2014 and nearly doubled its solar production in less than a year.