Renewable energy represented more than half the new power capacity in the world in 2015, reaching a record 153 gigawatts (GW) -- 15% more than the previous year, according to a new report.

Most of the gains were driven by record-level wind additions of 66GW and solar photovoltaic (PV) installations of 49GW, according to the the report from the International Energy Agency (IEA).

U.S. Department of Energy

The IEA projects global renewable electricity capacity will grow by 42%, or around 825GW by 2021. That's up 13% from the IEA's projections in 2015.

Wind accounted for 41% of all new electrical generation capacity installed in the U.S. in 2015, according to the the U.S. Department of Energy's Revolution Now: Update 2016 report. In 2015, total utility-scale solar power capacity in the U.S. grew 43% over 2014, reaching nearly 14,000 megawatts (MW).

The report also noted the price of renewables has fallen by as much as 94% in the last eight years due to "huge strides in research and investment."

Renewable energy generation costs now range from $30 per megawatt hour (MWh) to $50 MWh for both onshore wind and solar PV. Utility-scale solar power costs are expected to drop by about 25% from now through 2021. Onshore wind generation costs are expected to drop 15% on average by 2021.

U.S. Department of Energy The cost of power from wind turbines.

India is expected to be one of the world's fastest growing markets for renewables. Along with China, it is planning to deploy 100GW of new solar power between now and 2022.

For example, the India Oil Corp. and Oil India just announced $3.1 billion worth of projects to develop 2.7GW of new solar power capacity in that country.

The global wind industry had another record year in 2015. Overall, by the end of 2015, about 433GW of wind power was being generated around the globe, 17% more than in 2014; and wind power supplied more new power generation than any other technology, according to the Global Wind Energy Council.

U.S. Department of Energy The cost of solar power from utilities.

In the U.S. there are nearly 2,800 electric power-generating sources producing 4.1 terawatt hours of energy. (A terawatt is equal to 1,000 gigawatts.) The country's 49,000 wind turbines account for 4.7% of the country's electricity production, according to the U.S. Census Bureau.

The U.S. is the single largest market in terms of total installed wind capacity after China. The U.S. market added 4,000 new turbines for a total of just under 8.6GW in 2015, and its total installed capacity reached 74.4GW, according to the Global Wind Energy Council's (GWEC) semi-annual Global Wind Energy Outlook.

Global Wind Energy Council

Worldwide, the total installed wind turbine energy capacity is expected to reach just over 879GW by 2020 and 2.1TW by 2030, according to the GWEC's report. By 2050, global wind installations could reach 5.8TW.

Wind energy accounted for almost 31% of all new generating capacity installed in the U.S. over last 5 years, and provided more than 31% of the electricity in Iowa; 25% in South Dakota; and 12% or more in a total of nine states.

Renewable energy employs more people per unit of electricity than oil or gas. More than 1 million people worldwide are employed by the wind industry alone, a 5% increase over last year. Wind employment in the U.S. rose by 21% in 2015 -- 12 times faster than overall job creation in the US economy, according to the GWEC's report.

"If we double the global share of renewables by 2030, renewable energy employment would exceed 24 million people worldwide," the report stated.