Wind and solar power have grown faster than almost anyone predicted but projecting their future expansion remains difficult. Researchers at Chalmers University of Technology, Sweden, have developed what they call a computational “time machine” or a model that outperforms existing projection methods by using AI techniques to analyse historical growth patterns across countries.

Their central projection shows that onshore wind is likely to supply around 25 per cent of global electricity by 2050, with solar reaching about 20 per cent. This is consistent with the 2C target but falls short of what is required for 1.5C.

“Most models assume a smooth S-shaped growth curve, but that’s not how it actually looks in the real world. Growth often comes in bursts, and if you ignore that, you can misjudge how fast technologies will expand,” says Avi Jakhmola, PhD student at Chalmers University of Technology and first author of the paper published in Nature Energy.

By 2050, the model projects onshore wind reaching around 26 per cent of global electricity (central range: 20-34 per cent), and solar around 21 per cent (15-29 per cent). This broadly aligns with 2C-compatible pathways but falls short of what’s needed for 1.5C.

The projections also put the COP28 pledge to triple renewables capacity by 2030 in perspective. The pledge falls near the 95th percentile meaning that it would require growth rates rarely observed.

The researchers also tested what would actually be required if we are to reach the 1.5°C goal.

“If we start now, the required growth rates are demanding but not unprecedented, comparable to what the EU targets for wind with REPowerEU and what India has planned for solar power,” says Jakhmola. “But if we delay until 2030, the acceleration needed becomes much steeper and much more abrupt. The window for ramping up closes quickly.”

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