... Coal, a major contributor to global warming, was still the world's largest individual source of energy generation in 2024, a position it has held for more than 50 years, according to the IEA. ... in the EU, months of weak wind and hydropower performance led to a rise in coal and gas generation. ... winter wind lulls can last for weeks, requiring backup power sources that batteries alone can't provide - making the system more expensive to build and run. ...