HOPE · ENERGY SECURITY · WINTER 2026/27
When Britain and its neighbours need power at the same time, how secure is our supply?
A wind drought in Britain. A cold spell across Europe. Electricity demand rising on both sides of the Channel. In that situation, how much spare power would our neighbours have to sell us—and could Britain’s grid deliver it where it was needed?
Britain is transforming its countryside in the name of energy security. Yet this month, NESO requested emergency assistance twice. In one incident, France helped supply power that Britain’s own grid could not deliver to the right place. [1]
Before another reassuring winter headline, the public deserves to know what keeps the lights on when wind falls, cables are constrained and our neighbours also need their electricity.
Electricity must be available where people need it, when they need it, at a price they can afford. That is the test.
WE HAD POWER. THE GRID COULD NOT DELIVER ENOUGH OF IT.
In its explanation published on 14 October, NESO described two different events. Both involved transmission constraints.
During the Friday event, a bottleneck limited transfers from north to south. Wind generation then fell rapidly. NESO requested emergency assistance from France.
On Monday, transmission equipment in the South East remained unavailable after it had been expected back in service. Generation existed elsewhere, but enough could not reach London and the surrounding region.
Emergency assistance eventually reached 1,200 megawatts. NESO says its actions maintained secure supplies; customers were not facing an immediate loss of power. [1]
Our criticism is about the system ministers are responsible for delivering. Having electricity somewhere on the network is insufficient if it cannot reach the people who need it.
WHAT HAS CHANGED?
The Government’s latest annual electricity statistics show fossil-fuel generating capacity has fallen by 23 gigawatts since 2000. Nuclear output in 2025 fell to its lowest level since the 1980s. [3]
Meanwhile, total electricity imports reached 43.9 terawatt-hours in 2025. Britain also exported power; subtracting exports leaves net imports of 29.7 terawatt-hours. [3]
These figures describe a changed electricity system. They do not, by themselves, prove that its blackout risk has risen. To judge that, Parliament must examine the dependable contribution of the replacement capacity, its location and the conditions in which it is available.
WHO SUPPLIES THE ELECTRICITY BEHIND THE CABLE?
The Government’s own interconnector policy explains the trade-off: imports can meet demand when weather conditions would otherwise require more domestic generation held in reserve. It also recognises that interconnector flows can contribute to network constraints. [4]
That makes overseas supply part of the security calculation. A cable can carry electricity only when power and transmission capacity are available at both ends.
When Britain faces a cold, still spell, what happens if neighbouring countries are under pressure too?
That is a question for evidence: how much support remains available, through which routes, for how long and at what cost?
THE WINTER OUTLOOK MUST SHOW ITS WORKINGS
June’s preliminary NESO outlook forecast a 5.5-gigawatt margin, equivalent to 8.8% of forecast cold-weather peak demand. It expected adequate supply and generally net imports. This seasonal margin is not a guaranteed minimum cushion on every evening. [2]
NESO models difficult weather and outages, including cold, low-wind conditions across Europe. Calling the system “pure luck” would miss that work. The proper challenge is whether those assumptions adequately represent the risks Britain is taking. [2]
At drafting on 18 October, the full report was still awaited in NESO’s publication register. June’s report said it would arrive in October. [6]
A BETTER NUMBER NEEDS AN EXPLANATION
Appendix A of June’s report says an updated modelling method would produce a margin of approximately 10%. The headline elsewhere was 8.8%. [2]
If the next announcement reports an improved margin, NESO should explain separately what changed in the physical system and what changed in the calculation.
A revised method may be justified. Readers need a comparable account of what the improvement means.
EVEN THE 2030 PLAN KEEPS GAS AS BACKUP
The Government’s Clean Power 2030 plan expects to retain around 35 gigawatts of unabated gas capacity to protect security of supply. [5]
That is a substantial requirement for dependable backup alongside the proposed renewable system. Its fuel supply, availability and ability to deliver through the grid must be tested too.
HOPE’s position is that dependable plant should remain available until replacements can demonstrate equivalent security. Grid reinforcement and replacement generation must be ready for the demand they are expected to serve.
WHAT IT COSTS. WHAT IS MISSING. WHO PAYS.
The public deserves a combined account of generation, networks, backup, storage and operating costs.
How much is already included in published investment estimates? Which costs sit elsewhere? How much reaches electricity bills, how much falls on taxpayers, and how much is borne privately?
A promise of cheaper power must be tested against the complete system required to deliver it.
FIVE ANSWERS WE NEED FROM NESO
- Imports: how much overseas support is counted during the hardest hours, and what happens when it is reduced?
- Location: can that electricity actually reach the regions that need it?
- Duration: how long can storage sustain its assumed contribution, and how is it recharged during prolonged low renewable output?
- Backup: which dependable generators and fuel supplies are available when several things go wrong together?
- Cost: what does managing these conditions cost, and where will those costs appear?
MAKE THEM SHOW THE EVIDENCE
Our countryside is being committed to infrastructure with consequences lasting decades. Parliament should be able to judge the complete national impact before the legal targets keep driving the programme forward.
Our petition calls for a temporary suspension of the Climate Change Act’s carbon-budget and 2050 duties until Parliament has considered an independent assessment of the full costs and impacts.
Protect our countryside. Demand dependable energy. Make the costs public.
SIGN THE PETITION — MAKE THEM SHOW THE EVIDENCE
https://petition.parliament.uk/petitions/780321
One signature is all we ask. Share if you care.
Evidence and technical notes
Evidence checked on 18 October 2026. Prepared for publication on Monday 19 October. This article assesses the position before the full Winter Outlook; its findings must be checked against that report when published.
Scope: NESO operates the Great Britain electricity system. DUKES figures cited here cover the United Kingdom. A terawatt-hour measures energy over time; a gigawatt measures power at a moment. Annual net imports do not establish the amount needed at winter peak.
Historical comparison: no electricity system has ever provided an absolute guarantee. Conventional stations and fuel supplies have risks too. The argument here concerns the adequacy, cost and deliverability of the changing mix, rather than a claim that all imports are emergency purchases.
Interconnection: electricity trading is reciprocal and can improve resilience. Britain exported unusually large volumes during French nuclear outages in 2022, as DUKES records. Routine commercial imports, capacity commitments and emergency assistance are different arrangements. [3]
Interpretation: “Is NESO exposed?” asks how resilient the system is when several pressures coincide. The cited incidents demonstrate operational challenges; they do not establish an imminent national blackout. The comparison of June’s margin figures is a modelling question, not evidence of manipulation.
- NESO: Emergency Assistance—what it is, and why we used it over the last week, 14 October 2026
- NESO: Winter Outlook 2026/27—Early View, June 2026, pp. 4–5 and Appendices A–B
- DESNZ: DUKES 2026, Chapter 5—Electricity, especially pp. 4, 6–7
- DESNZ: Next steps for electricity interconnection in Great Britain, sections on changing roles and efficient operation
- DESNZ: Clean Power 2030 Action Plan—main report, sections on the path to 2030 and unabated gas
- NESO: Winter Operations publication register
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