Iberdrola, which owns ScottishPower, has committed to spend £24bn on upgrading the UK’s green energy infrastructure in a doubling of its initial investment plans.

Investment in renewable energy generation has exceeded investment in transmission capacity over the past decade, resulting in bottlenecks in the electricity network. The current infrastructure is reaching its capacity and is unable to transport much more electricity without reinforcing the network.

Earlier this year, National Grid’s Electricity System Operator said the UK’s grid needed a major revamp in order to connect a raft of new offshore wind facilities set to be built off the Scottish coast, costing an estimated £58bn.

Iberdrola said that two-thirds of its investment would be directed to transmission and distribution networks.

The transmission investments will include the new subsea interconnection Eastern Green Link 1, which will strengthen grid connections between the east coast of Scotland and north-east England. In power...