Key facts
- Consumers face higher energy bills if UK government doesn't speed up electricity grid upgrades for renewables.
- National Audit Office (NAO) warns costs from managing aging grid could reach £7.8bn annually by 2030 without faster action.
- A £70bn program is underway to modernize Great Britain's electricity network.
- Only 16 of 80 needed projects are finished, with most in early stages.
- Constraint costs, paid when the grid can't carry enough electricity, reached £1.9bn in 2025-26 and could hit £7.8bn by 2030.
- Ofgem estimates households could save £30 annually with timely upgrades due to reduced curtailment costs.
Consumers in the UK face potentially higher energy bills if the government does not accelerate a substantial program to upgrade the electricity grid, according to a warning from the National Audit Office (NAO). The public spending watchdog stated that without faster action, the costs associated with managing the nation's aging power network, which are ultimately passed on to the public, could escalate to £7.8 billion annually by 2030.
A £70 billion initiative is currently underway to modernize Great Britain's electricity infrastructure, including pylons, overhead lines, and substations, to accommodate increased power flow from renewable sources like wind and solar farms. However, the NAO reported that only 16 out of 80 necessary projects have been completed, with most still in their initial phases. Gareth Davies, head of the NAO, noted that the planned upgrades are ambitious and that failure to implement them promptly will impede economic growth and increase consumer bills.
When the grid is unable to transmit sufficient electricity, the system operator incurs costs by paying wind farms to curtail output and gas plants to increase generation to meet demand. These "constraint costs" reached £1.9 billion in 2025-26 and are projected to rise significantly without timely upgrades. The investment required from transmission owners will necessitate a more than fourfold increase in their annual spending on upgrades. Ofgem, the industry regulator, believes that successful and timely upgrades could save households approximately £30 per year by reducing these constraint costs. However, the NAO cautioned that meeting the required schedule is "very challenging," with some projects already expected to extend beyond 2030, creating a gap where new generation may connect before grid enhancements are complete.
The NAO also highlighted a lack of sufficient data transparency from Ofgem, the National Energy System Operator (Neso), and the government regarding project costs and progress. Geoffrey Clifton-Brown, chair of the public accounts committee, emphasized the grid's critical role in supporting the clean energy transition and meeting rising demand, urging for timely delivery and transparent reporting. Ofgem welcomed the NAO's recommendations, stating that the upgrades would reduce system constraints and help shield consumers from volatile international gas prices. The energy minister, Michael Shanks, acknowledged the report as a reminder of past underinvestment and highlighted ongoing reforms to build necessary infrastructure. Neso also welcomed the findings and affirmed its commitment to balancing costs while ensuring supply security.