The year sunlight went global: how the Paris Agreement brought solar power to the world

Summary

Ten years after the Paris Agreement, when countries made the first universal commitment to constrain greenhouse gas emissions, the growth of solar power has been the most dramatic response. Solar is the fastest-growing electricity source in the world’s history, providing around ten times more electricity now than in 2015, when it provided just 1% of global generation. In 2024, solar made up 6.9% of global generation, rising further to 8.8% in the first half of 2025 —  and in many countries, its share of the electricity mix is considerably higher. 

In the decade since the Paris COP21 Summit, solar leadership has moved from the richest nations to emerging economies. In 2015, mature economies accounted for three-quarters of global solar electricity generation; today they make less than half. In the three countries highlighted in this report, solar has grown much faster than the global average – nearly 20-fold in India and over 20-fold in China. Brazil built one of the fastest solar expansions in the world, with capacity growing by around 70% per year on average.

The Paris Agreement contributed to these trends by establishing national targets, raising finance, establishing alliances to lower barriers and shaping industrial policy, which brought dramatic cost reductions. It was also during the COP21 Paris Summit that the International Solar Alliance (ISA), an intergovernmental organisation with multiple member countries and led by India and France; and the Global Solar Council, an industry association with members across the solar value chain promoting policies and cooperation.

China, India and Brazil all contributed by increasing national solar deployment, building manufacturing industries, launching the ISA and developing policies that have since been replicated across the world.