The world installed more new renewable energy last year than coal, as countries attempt to shift away from fossil fuels and take advantage of massive cost reductions in wind and solar technology.

More than half of all energy generation capacity added in 2015 came from renewable sources, as the world installed more than half a million solar panels a day and two wind turbines every hour, the International Energy Agency announced Tuesday.

“We are witnessing a transformation of global power markets led by renewables and, as is the case with other fields, the center of gravity for renewable growth is moving to emerging markets,” IEA executive director Fatih Birol said in a statement.

Those statistics only reflect the total amount now able to be produced, not the energy that was actually generated.

The agency said renewables would be the fastest-growing source of electricity production over the next five years and would “rapidly close the gap with coal.” More than 65 percent of this capacity will come from development in China, the U.S., the European Union and India ― also the world’s four biggest polluters.

The cost of renewable energy has fallen dramatically in recent years as funding for new technology has skyrocketed. Investment in clean energy capacity beat that of fossil fuels 2 to 1 between 2008 and 2015, according to the United Nations Environment Program.

Leaders in the environmental community praised the statistics. Michael Brune, executive director of the Sierra Club, hailed the move as a “historic milestone,” but he called on leaders to “maintain our focus to keep up the momentum” behind the clean energy transition.

“The international community has reached a turning point as we hit the accelerator on the transition to a clean energy economy,” Brune said in a statement. “This news doesn’t just mean the world installed more renewable energy than dirty coal ― it means cleaner air, new jobs, and a more stable climate.”

While the IEA did raise its estimate for the amount of renewable energy produced by 2021, the agency also warned of barriers to entry in developing countries and renewed calls for “stronger policy efforts” in the heat and transportation sectors.