Renewables giant NextEra Energy has agreed to pay $1bn for the underwater 400MW Trans Bay Cable that brings in 40% of San Francisco’s electricity, amid a growing overlap between the US renewables and transmission sectors.

NextEra will buy the transmission project from SteelRiver Infrastructure Partners. The purchase price includes the assumption of debt, and the deal is expected to close in 2019 after gaining approval from both state and federal regulators.