The global energy supply is radically changing. 

Solar and wind power’s share in the global electricity mix has almost quadrupled in a decade, from 5% in 2015 to around 19% today. Together with hydropower, biomass and geothermal energy, renewables now supply around 35% of the world’s electricity.

However, most energy globally is consumed for heating and transportation, and the proportion of renewable energy in these sectors is still low.

Renewables make up only 15% of the world’s total energy consumption, an increase of only 2% since 2015. So where is clean energy making big strides and where does it need to go next? 

Solar power is expanding the fastest 

Solar power is the fastest growing energy sector worldwide and is expected to continue booming for decades to come. 

This growth has been driven by plummeting costs in recent years and the fact solar modules can be quickly installed almost anywhere.

Operating solar modules around the world now have a total output of around 2,200 gigawatts (GW) — covering 9% of global energy demand compared to only 1% in 2015. Last year alone modules with an output of 553 GW were installed, according to calculations by industry association Solarpower Europe. This alone is more capacity than all the world’s 411 nuclear reactors, which can supply an estimated 371 GW.

Solar has the potential to cover 73% of the world’s energy needs for electricity, heat, transportation and industry at an affordable cost, according to a 2021 study. The rest could be covered primarily by a mixture of wind power, biomass, hydropower and geothermal energy.

China remains frontrunner

China has long led the pack when it comes to solar expansion. 

It increased its solar capacity by 300 GW in 2024, according to forecasts by SolarPower Europe, which they expect should be able to generate more than 10% of its electricity. With a total output of around 955 GW, China now accounts for some 44% of all modules installed worldwide.

The total installed capacity of photovoltaics at the end of 2024 was 419 GW in the rest of Asia, 399 GW in Europe and 329 GW in the US.

China also significantly dominates the market for making solar modules, with 86% of them produced in its factories. 

Increased efficiency is making renewables even cheaper

Today, electricity from new solar modules costs only a fifth of what it did in 2010, and wind prices have dropped by 50%. This is due to mass production and advances in efficiency. Solar modules have roughly doubled their electricity output compared to 15 years ago, while modern wind turbines have tripled theirs.

Compared to new fossil fuel power plants, generating electricity from wind and solar power is now significantly cheaper almost everywhere, costing under 50% less. 

Electricity from solar parks and onshore wind turbines is now being generated in the US and Europe for €0.03 to €0.09 per kilowatt hour (kWh). In Europe, electricity from a new coal or gas power plant costs between €0.11 to €0.33 per kWh and from a new nuclear power plant €0.14 to €0.49 per kWh. 

Wind power expansion breaks records 

Last year saw more wind capacity installed worldwide than ever before, according to the World Wind Energy Association (WWEA), an international association representing the sector. Wind energy now has a total capacity of around 1,200 GW, covering roughly 10% of global electricity demand. 

China is also a global leader when it comes to the expansion of wind power. According to estimates from the WWEA, new plants with a capacity of 100 GW were added last year, increasing overall output to around 475 GW. 

China is followed by the US (153 GW), Germany (71 GW), India (47 GW), and Spain and Brazil with 31 GW each. 

Falling battery prices also boosting climate protection

Storing electricity is also becoming cheaper than ever, falling 90% between 2010 and 2025, according to energy research organization BloombergNEF.

China is also driving this battery boom and has built large factories to produce them in recent years. Their falling prices has helped make electric cars sold in China cheaper than those with a combustion engine. In the second half of 2024, e-car sales in China — the world’s largest car market — outnumbered those with combustion engines.

And these falling battery prices are also having a positive impact on renewable expansion — enabling solar power generated during the day to be stored cheaply overnight and weather-dependent wind power to be used when it is needed.

The United Arab Emirates is one example of many countries that are expanding their battery storage systems. The country is currently building a battery storage facility with a capacity of 19 GW hours alongside a large 5.2 GW solar park.

Germany is also aiming to increase its battery storage to secure its power supply from wind and solar. Renewable energy currently makes up 63% of the country’s electricity mix and is set to rise to 80% by 2030. Energy suppliers are planning to expand their storage capacity from 15 GW hours now to over 200 GW hours.

Is this momentum enough to protect the climate?

The expansion of solar, wind and battery technology are playing a key role in enabling the world to transition away from the fossil fuels that are driving planetary heating. In Europe, for example, the share of renewables in the electricity mix reached 47% in 2024 and fossil fuels fell to an historic low of 29%. 

However, the current momentum is not enough to limit global heating to 1.5 degrees Celsius (2.7 Fahrenheit) above pre-industrial levels, as agreed in the Paris climate agreement.  

To reach these targets, scientists say this already booming expansion of renewables must be accelerated significantly and CO2 must also be removed from the atmosphere on a large scale. 

Edited: Anke Rasper

This article was adapted from German.