Decommissioning to drive 23% of solar buildout in the 2040s, says Wood Mackenzie

A new analysis from research firm Wood Mackenzie looks at what happens as large-scale solar and wind farms built years ago start reaching the end of their working life. By 2040, more than 2.5 terawatts of solar and wind projects worldwide will hit that point. Owners then face a choice: upgrade the aging equipment in place, or tear it down and rebuild with newer technology on the same site, a process called repowering.

The report finds this replacement cycle will become a major driver of new installations. By the 2040s, decommissioning old projects and rebuilding them is expected to account for 23% of new solar construction and 44% of new wind construction globally. Wind is further along in this cycle since it was built out earlier than solar, but solar's older fleet will grow substantially by 2040. The effect will be strongest in Europe, where more than 70% of installations in established markets could come from repowering old sites in the 2040s, compared with as little as 1% in newer markets in Asia.

This is large-scale utility and grid infrastructure, not rooftop home systems, so it does not point to any direct action for homeowners. But it signals that the solar and wind industry supplying the broader grid is entering a long-term replacement phase, with equipment sales expected to be more than 60% higher in 2050 than in 2026, even as growth in new capacity slows. That could shape how utilities plan power supply and pricing in the coming decades.