Five things we learnt this week

Leader

Utility Week’s deputy editor says that while electricity and gas networks both suffered cuts in Ofgem's RIIO3 responses, the messaging for gas is different - and more ominous.

Rob Horgan, deputy editor

National Grid knew about fault seven years before Heathrow substation fire

A failure by National Grid Electricity Transmission (NGET) to act on elevated moisture levels found at its North Hyde substation in 2018 “most likely” caused the catastrophic fire which led to Heathrow Airport shutting down for an entire day. That is according to the National Energy System Operator’s final report into the incident, with Ofgem now opening an official enforcement investigation into NGET.

Macquarie injects £1.2bn into Southern Water

Southern Water has secured new equity to the tune of £1.2 billion from Macquarie to support the company’s largest investment programme to date and reduce debt levels. The deal means the Australian infrastructure investor has committed more than £2.8 billion in the water company since 2021.

Energy sector debt exceeds £4bn

The amount of debt and arrears faced by energy customers has exceeded £4 billion, Ofgem’s latest figures show. An update published by the regulator on Friday shows that the total figure between Q4 2024 and Q1 2025 rose by 8%, from £3.85 billion to £4.15 billion. This is a 25% increase on Q1 2024 and an almost doubling of the figure for the same period in 2023.

Three-fold increase in GB’s flex markets

Britain’s electricity networks secured a record 9GW of flexibility during the past year. That represents an almost three-fold annual increase on the 3.2GW of flexibility contracted for the 2023/24 reporting period. The Energy Networks Association (ENA) estimates that customers have saved more than £300 million as the result of flexibility procured during the past year.

CfD support could be extended to floating solar farms

The government is exploring further support for floating solar projects through Contracts for Difference (CfDs) and the planning system. The long-awaited UK Solar Roadmap 25, published jointly by the government and industry, sets out steps required to deliver the Clean Power Action Plan’s ambition of 45-47GW of solar power deployment by 2030.