More than 3.5 TW of wind and solar capacity is now operating globally, but ageing equipment could create a major new investment cycle as around 2.5 TW of projects reach key renewal decisions by the 2040s, according to global consultancy firm Wood Mackenzie.
In its latest Horizons report, Renewing renewables: The next chapter in the energy transition, the consultancy said owners will increasingly have to choose between abandoning sites, extending the life of existing equipment or fully repowering projects.
Decommissioning is already gathering pace in wind. More than 30 GW of wind capacity is expected to have been retired worldwide by the end of 2026, with around two-thirds taken offline between 2022 and 2026. Solar deployment began later, but its ageing fleet is expected to overtake wind in terms of decommissioning before 2040.
Repowering can offer developers an alternative to greenfield development by making use of established grid connections, planning approvals and existing sites. Wood Mackenzie said the capital and operating costs can be broadly comparable with new projects, while established locations can offer advantages in terms of wind resources and project development.
In Germany, wind speeds at sites decommissioned so far this decade are around 4% higher than at greenfield projects coming online on average, with the difference reaching as much as 30% at some locations. A 4% increase in wind speed can translate into approximately 7% higher capacity factors and 7% lower levelised cost of energy, assuming other factors remain unchanged.
Søren Lassen, head of wind at Wood Mackenzie, said the industry was entering “a new chapter in the energy transition” in which renewal would become increasingly important.
The impact could extend to renewable targets and power markets. Wood Mackenzie estimates that decommissioning could account for 44% of global wind installations and 23% of solar installations during the 2040s. In Germany, widespread repowering could reduce power prices by 12–19% during the decade.
For equipment manufacturers, replacement demand could offset slower growth in net capacity. Wood Mackenzie expects equipment sales volumes to be more than 60% higher in 2050 than in 2026, driven by the replacement of ageing renewable assets.
