Brits warned of rising electricity bills as grid bottleneck costs set to triple by 2035
Key Points
- The cost of managing bottlenecks on Britain's electricity grid could roughly triple between 2031 and 2035.
- When the network hits a bottleneck, NESO has to keep the system from overloading. It does this through "balancing actions".
- NESO said that without new network capacity, available clean power is wasted and gas generation has to be turned up in its place, leaving bill payers facing additional cost.
- "Without reinforcement, the constraint costs from balancing the system could see around a three-times increase between 2031 and 2035," the group said.
- The data shows that if Great Britain kept its existing transmission network into 2030, constraint costs in that single year could reach around £12.7 billion.
The cost of managing bottlenecks on Britain’s electricity grid could roughly triple between 2031 and 2035 if the network is not reinforced in time, with households left to cover the bill, the National Energy System Operator (NESO) has warned.
In a new report, the regulator reconfirmed that the scale of investment needed in the grid through to the mid-2030s remains broadly unchanged from its 2024 assessment, and that delaying it would push up costs for bill payers.
How bottlenecks drive up bills
When the network hits a bottleneck, NESO has to keep the system from overloading. It does this through “balancing actions”:
- Paying generators to stop producing, often wind farms in areas with high renewable output.
- Paying other generators outside the bottleneck to produce more to meet demand elsewhere.
These balancing actions are a routine part of running the grid. The problem comes when they become large and sustained.
NESO said that without new network capacity, available clean power is wasted and gas generation has to be turned up in its place, leaving bill payers facing additional cost.
Costs could triple by 2035
NESO set out the central warning plainly in its report:
“Without reinforcement, the constraint costs from balancing the system could see around a three-times increase between 2031 and 2035,” the group said.
At the same time, limited grid capacity would delay new connections for homes, businesses and clean generation, holding back economic growth.
The data shows that if Great Britain kept its existing transmission network into 2030, constraint costs in that single year could reach around £12.7 billion.
Building new network capacity would cut those onshore costs by around 75%, bringing them down to £3.6 billion in one pathway and £2.8 billion in another.
What NESO wants next
NESO recommended that the regulator, the Office of Gas and Electricity Markets (Ofgem), consider its most mature, near-term projects for early investment.
It also pressed for faster delivery through the UK Government’s Transmission Acceleration Action Plan, and for coordinated action on planning and consenting, warning that delays increase costs and reduce the benefits to the wider system.
