The rapid rise of renewable energy is increasingly being used to satisfy growing electricity demand rather than replacing fossil fuels, according to new research from the University of Sussex.
The study, published in Nature Reviews Clean Technology, highlights how soaring energy use—driven by artificial‑intelligence data centres and expanding air‑conditioning needs in a warming climate—is threatening to erode the environmental gains made by clean power.
Researchers from Sussex and Vienna’s Central European University report record global growth in solar generation during the first three quarters of 2025. For a brief period, this surge in clean electricity outpaced worldwide demand. However, the authors warn that this delicate advantage is already slipping as consumption accelerates once again.
Despite rapid expansion of wind and solar since the 2015 Paris Agreement, emissions from the power sector have continued to climb because electricity demand has risen even faster. The analysis identifies AI‑driven data centres and increased cooling needs as major contributors, alongside the electrification of transport and consumer trends such as larger vehicles. These pressures, the report argues, are cancelling out efficiency improvements made by individual nations. Projections to 2030 suggest that most new renewable capacity could be absorbed by rising demand unless governments act to curb consumption.
“Renewables are scaling at record speed, but demand growth from data centres, cooling and transport is running just as fast,” said Professor Felix Creutzig, Bennett Institute Chair at the University of Sussex. “We need policies that curb unnecessary energy use and shape demand so that clean electricity can have the intended effect of cutting emissions from fossil fuels.”
The report points to evidence from the EU and major cities showing that reducing demand can align with economic growth and improved wellbeing through better efficiency and urban planning. The authors conclude that pairing renewables with strong demand‑side strategies is now essential for real progress on decarbonisation.
The University of Sussex’s Bennett Institute for Innovation and Policy addressed these issues further at its annual Research Symposium on 19 February, themed Zero Hour for Energy Policy: Researching the Race to Net Zero.
Image: Aerial view of the University of Sussex. Credit: Getty
