Renewables beat coal as largest source of power capacity 

While coal continues to crank out electricity for millions of people in developing nations, renewable energy is rapidly catching up and last year, overtook coal as the world's largest source of installed power capacity.

About half a million solar panels were installed every day last year and two wind turbines went up ever hour in 2015 – which may be seen as a turning point for renewables, led by solar power and wind. The astonishing figures come via the International Energy Agency (IEA), which in a recent report, raised its renewable growth forecast.

In 2015 over half of new power capacity came from renewable energy – reaching 153 gigawatts, or 15% more than last year. The amount of solar and wind added in 2015 were both record-setting; PV additions reached 49 GW and wind achieved 66 GW.

About half a million solar panels were installed every day last year and two wind turbines went up ever hour in 2015

"‌There are many factors behind this remarkable achievement: more competition, enhanced policy support in key markets, and technology improvements. While climate change mitigation is a powerful driver for renewables, it is not the only one. In many countries, cutting deadly air pollution and diversifying energy supplies to improve energy security play an equally strong role in growing low-carbon energy sources, especially in emerging Asia," states the latest edition of the IEA’s Medium-Term Renewable Market Report.

The 153 GW of installed green energy was more than the total power capacity of Canada and greater than the amount of conventional fossil fuel or nuclear power added in 2015. While renewables surpassed coal in their cumulative share of power capacity, they have not yet knocked fossil fuels from the top of the heap when it comes to electricity generation. That's because renewables, due to their intermittency, cannot produce power at the same constant level as coal or nuclear.

According to the IEA in 2015 coal power plants produced close to 39% of the world's power while renewables, including hydroelectric dams, accounted for 23%. However the IEA expects that number to climb to 28% by 2021, when renewables will supply the equivalent of all the power produced currently in the US and the EU combined.

The IEA now sees renewables growing 13% more between 2015 and 2021 than it did in last year’s forecast, due mostly to "stronger policy backing in the United States, China, India and Mexico." The costs of installing solar and wind have dropped, and expected to drop considerably – 25% less for PV solar and a decrease of 15% for onshore wind, for the forecasted period, according to the agency.