wind turbines

Wind turbines reflect in water near Pattensen, Germany. (Photo: Julian Stratenschulte/Getty Images)

Renewable energy may be on the verge of a breakthrough. Endless power sources like wind, water and sunlight are on pace to produce more global electricity than natural gas within three years, according to a new report from the International Energy Agency, thus dethroning gas as the world's No. 2 electricity source behind coal.

Renewables are already the fastest-growing sector in power generation, the IEA reports, and they're expected to increase by 40 percent worldwide over the next five years. That would mean renewable sources overtake natural gas by 2016 and represent 25 percent of all electricity production by 2018, up from 20 percent just two years ago.

"As their costs continue to fall, renewable power sources are increasingly standing on their own merits versus new fossil-fuel generation," IEA director Maria van der Hoeven said Wednesday as she unveiled the report at a New York energy forum. "This is good news for a global energy system that needs to become cleaner and more diversified, but it should not be an excuse for government complacency, especially among OECD countries."

"OECD countries" are members of the Organization for Economic Cooperation and Development, a 34-nation coalition that promotes economic growth, and many can easily afford to invest in technologies like wind or solar power. But according to the IEA, two-thirds of the growth in renewable energy will come from non-OECD developing nations, especially China, due to falling prices and surging demand for electricity. Fading subsidies will likely slow growth in Europe and the U.S., although President Obama's new climate change plan does call for expanded renewable power on federally owned land.

"Many renewables no longer require high economic incentives," van der Hoeven said Wednesday. "But they do still need long-term policies that provide a predictable and reliable market and regulatory framework compatible with societal goals. And worldwide subsidies for fossil fuels remain six times higher than economic incentives for renewables."

Beyond the investments by developing nations, the IEA says renewables are also "becoming cost-competitive in a wider set of circumstances." Wind now competes well with fossil fuels in several markets, including Brazil, Turkey and New Zealand, and solar is increasingly attractive in places with high peak prices for electricity. Some countries now enjoy decentralized solar power that's cheaper than retail electricity, the agency reports.

While the rise of renewable power is key to fighting climate change, its benefits vary by source. About 80 percent of all renewable energy is hydroelectricity, which doesn't emit greenhouse gases but can still harm ecosystems by damming rivers. Other sources also come with drawbacks — poorly sited wind farms can kill birds and bats, for example — but new technologies and better industry practices are expected to reduce such risks.

Hydropower will likely remain king of renewables for years, the IEA predicts, given its longer history and recent growth in developing countries like China and Brazil. Wind, solar, geothermal and biofuels are also forecast to grow quickly in the next five years, but they'll still only supply about 8 percent of global energy in 2018, up from 4 percent in 2011.

Meanwhile, the amount of heat-trapping carbon dioxide in Earth's atmosphere recently hit 400 parts per million, the highest level in human history. "The 400-ppm threshold is a sobering milestone," U.S. climate researcher Tim Lueker said last month. "[It] should serve as a wakeup call for all of us to support clean energy technology and reduce emissions of greenhouse gases, before it's too late for our children and grandchildren."

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Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Renewables outpacing natural gas, IEA says
Renewable energy will surpass natural gas as the planet's No. 2 electricity source by 2016, according to a new report from the International Energy Agency.