In a report published in April 2025, the International Energy Agency (IEA) confirmed that global renewable energy capacity has, for the first time in history, surpassed the total installed capacity of fossil fuel power generation. Renewables now account for 51% of global electricity generation capacity. This is a genuine milestone.
What the Numbers Actually Say
In 2024, the world added more new renewable energy capacity than in any previous year. Solar alone accounted for over 400 gigawatts of new installation. Wind added another 120 GW. China is the single most significant driver of this number, accounting for roughly 60% of new renewable additions in 2024.
The Important Caveat: Capacity vs Generation
Electricity capacity — the maximum amount a power plant can produce at full output — is not the same as electricity generation — how much power is actually produced over time. A solar farm can only generate electricity when the sun is shining. Their “capacity factor” is typically 15-25% for solar and 25-40% for wind.
Although renewables have crossed the 51% capacity threshold, they currently supply approximately 35% of actual global electricity generation. Fossil fuels still generate the majority of the world’s electricity.
The Storage Problem: The Remaining Challenge
The central challenge for a fully renewable grid is matching supply with demand when the sun isn’t shining and the wind isn’t blowing. The most promising solutions being developed include:
- Long-duration batteries — Iron-air, vanadium flow and sodium-ion batteries that can store energy for days
- Green hydrogen — Excess renewable electricity used to split water into hydrogen, which can be stored and used later
- Enhanced transmission grids — Moving electricity across larger geographic areas balances supply and demand
- Demand flexibility — Smart systems that shift electricity demand to when supply is abundant
What This Means for Climate Goals
The Paris Agreement’s goal of limiting global warming to 1.5°C requires global CO₂ emissions to reach net zero by approximately 2050. The IEA’s analysis suggests that if current renewable deployment rates are maintained, the power sector could be essentially decarbonised in most major economies by 2035-2040.
“Passing the 50% capacity threshold is the beginning of the second act of the energy transition, not the end of the first.” — Dr. Fatih Birol, IEA Executive Director