UK network operator National Grid strengthened in US renewables with a deal to buy Minneapolis-based developer Geronimo Energy.

National Grid will pay an initial $100m for Geronimo, with further payments depending on pipeline development milestones.

The London-listed group is also spending $125m for a 51% share in a 378MW wind and solar portfolio developed by Geronimo, all with long-term PPAs in place, which it will co-own with Washington State Investment Board (WSIB).