Renewables
UK grid bottlenecks constrain rapid renewable energy growth
Inadequate transmission infrastructure is forcing the United Kingdom to curtail wind generation and rely heavily on natural gas to balance its power grid.
Key points
- Grid balancing costs in the UK reached a record £505 million in September.
- Transmission constraints between Scotland and England continue to drive high curtailment costs.
- National Grid has proposed £4.5 billion in new investments to expand network capacity.
What happened
The United Kingdom is facing severe transmission bottlenecks as the deployment of renewable energy outpaces the modernisation of its power grid, according to reporting by OilPrice.com. Despite significant investments in wind and solar capacity, grid inefficiencies have forced the system operator to regularly curtail renewable generation while relying on natural gas and emergency imports to maintain stability.
In September alone, balancing costs on the British grid reached £505 million, a record monthly high. On 14th October, the grid operator spent £47.9 million to switch off wind farms experiencing oversupply, while simultaneously firing up gas plants in supply-deficient regions. Consultancy LCP Delta reported that around 9 GW of wind and hydropower capacity was paid to halt production on that day.
A primary driver of these inefficiencies is the transmission constraint between Scotland, which generates a large share of the country's wind power, and high-demand centres in England and Wales. The limited capacity of high-voltage cabling along this route has driven up constraint management costs. Meanwhile, the queue for new grid connections grew substantially between late 2024 and mid-2025, leaving numerous green energy projects stranded.
What comes next
To address these structural challenges, National Grid has submitted a package of 19 proposed projects representing approximately £4.5 billion in investment across England and Wales. This initiative forms part of a broader £31 billion planned investment in transmission infrastructure between 2026 and 2031 aimed at accommodating rising clean power generation and demand.
Why it matters
The situation highlights a critical lesson for energy transition planners globally: generation capacity alone is insufficient without parallel investments in transmission and distribution networks. For developing energy markets in Africa, where grid stability and access remain paramount, the British experience underscores the importance of integrated infrastructure planning. While the United Kingdom maintains universal electricity access, according to 2024 World Bank figures, network bottlenecks can still severely undermine the efficiency and economic benefits of renewable integration.
Original reporting
This article draws on the following reports. Read them in full on the publishers’ sites.
Context from CEII
Renewables are the fastest-growing part of the world’s energy system. The COP28 goal is to triple capacity by 2030, and solar mini-grids are the fastest route to power for millions of people without electricity.
40.2% of electricity in United Kingdom was renewable in 2021Countries in this story
Written by the CEII Desk, the Centre’s automated newsroom, from the reporting credited above and CEII’s own data. Facts are attributed to their sources; the publishers have not reviewed this article. Spotted an error? Tell our editors.
