Over 500,000 solar panels were installed each day last year, as renewables passed coal to become the largest source of power capacity globally. The latest report, published by the International Energy Agency (IEA) found that renewables, largely spearheaded by solar and wind power, accounted for more than half of the new power capacity around the planet.

Installation of green energy sources was up 15 percent on 2014, leading the IEA to change its five-year forecast for renewables, expecting renewables to grow by 13 percent more between 2015 and 2021 than was predicted last year. This is largely being driven by Asia, and in particular China, with India and the United States also significantly contributing, but they warn that Europe is stumbling. Once the leader in green technologies, the growth in this sector in the EU has significantly slumped.

“I am pleased to see that last year was one of records for renewables and that our projections for growth over the next five years are more optimistic,” explains the IEA’s executive director Dr Fatih Birol. “However, even these higher expectations remain modest compared with the huge untapped potential of renewables. The IEA will be working with governments around the world to maximize the deployment of renewables in coming years.”

The new capacity added has accounted for a record 153 Gigawatts (GW), with wind making up 66GW and solar 49GW. Despite the seeming turning of the tides in favor of renewables, and green tech being the fastest growing source of electricity generation, they are still only expected to make up 28 percent of all generation globally by 2021. This, the IEA say, is far short of what is needed if the Paris climate agreement is to be met, and the warming of the planet kept below 2°C (3.6°F).

While the push to limit climate change is a big driver for the installation of renewables, particularly as when the Paris climate agreement comes into force this November many countries will look to meet their targets through green energy, it is by no means the only cause. Particularly in Asia, the dramatic and worrying increases in air pollution are playing a large role, while diversifying energy supply as well as improving energy security is also a factor.

“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,” says Dr Birol. With the cost of wind having dropped 30 percent in six years, and solar have declined by 80 percent, the shift to renewables is becoming far more competitive, and expected to continue.