Britain is being asked to finance one of the greatest transformations of its electricity system in generations. Hundreds of major transmission projects, new substations, pylons, cables and offshore connections are being developed to accommodate an energy system designed around assumptions made several years ago. Now one of Britain’s largest energy companies is publicly asking whether those assumptions , and the enormous investment programme built around them , still represent value for money.
For months, we have been asking a straightforward question: if the assumptions behind Britain’s electricity transformation have changed, why should billions of pounds continue to be committed as though nothing has changed?
On 19 August 2026, that question moved decisively into the mainstream energy debate. EDF Energy called on Ofgem and the National Energy System Operator, NESO, to undertake what it described as a strategic review of forthcoming Pathway to 2030 transmission investments.
That intervention matters because EDF cannot realistically be dismissed as an opponent of electricity infrastructure or low-carbon generation. It operates nuclear generation, supplies millions of customers and has major interests throughout the British energy system. Nor is EDF arguing that Britain should stop upgrading its electricity network. Its position is considerably more important than that: where investment is necessary and provides genuine consumer benefit, it should proceed, but the assumptions and economics supporting the programme need to be reassessed against the circumstances Britain faces today.
In other words, the question is no longer simply whether Britain needs more electricity infrastructure. It plainly does. The question is whether we are still building the right infrastructure, in the right places, at the right time, for the generation that is actually going to arrive , and whether the costs can still be justified to the consumers who ultimately pay for it.
That goes directly to the heart of what we have been examining through our wider Britain Replanned investigation.
THE ORIGINAL PLAN WAS BUILT AROUND A SET OF ASSUMPTIONS
To understand why EDF’s intervention is so significant, it is necessary to return to the origins of the programme. In July 2022, the Electricity System Operator published its Pathway to 2030, incorporating the Holistic Network Design. One of its central purposes was to establish the transmission infrastructure required to accommodate the Government’s ambition for 50GW of offshore wind by 2030.
The scale was extraordinary. NESO’s predecessor described the programme as one of the largest investments in Britain’s critical electricity infrastructure since the major transmission expansion of the 1950s and 1960s. The wider Pathway to 2030 programme was associated with up to £54 billion of investment in the GB network, while detailed Pathway documentation identified 94 transmission reinforcement projects and estimated the onshore reinforcement component alone at around £21.7 billion.
Then came Beyond 2030. Published in March 2024, it proposed another enormous stage of transmission development extending into the following decade and identified around £58 billion of further direct network investment.
These figures should not simply be added together and presented as one bill because they refer to different programmes, changing scopes and overlapping periods. Nevertheless, they demonstrate the scale of what Britain committed itself to pursuing: an infrastructure transformation measured in tens of billions of pounds, much of it established strategically before individual routes had completed planning, land negotiations, geological work, environmental assessment or detailed construction design.
There is nothing inherently wrong with planning infrastructure ahead of need. A national electricity system cannot wait until every generator has arrived before transmission capacity begins to be constructed. The problem comes when early modelling assumptions effectively become fixed commitments even while the circumstances used to justify them continue to change.
That is precisely why continuing review is essential.
EDF SAYS THE CONTEXT HAS CHANGED MATERIALLY
EDF’s August intervention is important because the company says the circumstances surrounding the transmission programme have changed materially since Pathway to 2030 was originally developed. It highlights escalating construction costs, changing generation assumptions and substantial delays affecting connections.
EDF says its analysis of Ofgem material indicates that the costs of some transmission projects have risen by around two to three times compared with initial Transmission Owner forecasts. At the same time, EDF reports that its own generation projects are experiencing an average grid-connection delay of around two years, while the most severe delays exceed five years.
This matters enormously because a transmission system is designed around assumptions about future electricity flows. Engineers and system planners need to estimate which generators will connect, their capacity, where they will connect, how much power will move between different parts of the country and when those flows will occur.
If the generation arrives several years later than assumed, if projects are downsized, cancelled or replaced, or if demand develops differently from the original forecasts, the economic justification for some infrastructure may change. A transmission project that offered strong value for money under one generation scenario may not necessarily offer the same value under another.
EDF specifically draws attention to offshore wind. Pathway to 2030 incorporated substantial assumptions regarding new Scottish offshore generation, including roughly 11GW of ScotWind-related capacity expected to connect by 2030. Yet the development timetable for parts of that generation has moved considerably since the original network planning exercise.
The significance is obvious. Transmission infrastructure cannot sensibly be assessed independently of the generation it exists to transport. If generation dates move, the network programme must be capable of being re-examined alongside them.
THE CONSUMER ULTIMATELY PAYS
This debate can appear highly technical because it involves system modelling, connection dates, transmission boundaries and engineering requirements. But behind every diagram and network investment decision is a much simpler reality: the consumer pays for the infrastructure.
EDF, referring to Ofgem’s RIIO-3 Final Determinations Impact Assessment, says the transmission-network component of the average consumer bill is forecast to increase from approximately £44 in 2025 to around £105 by 2030. That represents an increase of roughly 140 per cent.
EDF also says Ofgem has estimated that Britain’s Transmission Owners could collectively spend approximately £70 billion between 2026 and 2031. The company makes the important point directly: the costs of transmission network upgrades are ultimately recovered from consumers through charges incorporated into electricity bills.
That fact should fundamentally change the nature of the debate. It is no longer sufficient to argue that a particular project should proceed simply because “the grid needs upgrading”. Britain undoubtedly needs grid investment, but that statement alone cannot justify every proposed project, every route or every timetable.
The correct questions are more demanding. Is a particular reinforcement still necessary on the original timetable? Is the generation that justified it still expected to connect? Has the project’s capacity been reassessed against the latest forecasts? Are alternative solutions available? Have delays elsewhere in the system changed the urgency? Most importantly, does the consumer benefit generated by the project still exceed the cost that households and businesses will eventually be required to carry?
These are not anti-grid questions. They are the questions that should accompany any infrastructure programme involving tens of billions of pounds of public-facing costs.
EDF IS QUESTIONING WHETHER PATHWAY TO 2030 REMAINS THE BEST APPROACH
Perhaps the most striking part of EDF’s statement concerns the lack of publicly available information. The company argues that current transparency is insufficient to determine properly how project costs have changed, how network requirements have evolved and, crucially, whether the Pathway to 2030 network remains the best approach.
That is an important intervention. EDF is not claiming that the entire Pathway programme is wrong, nor does its statement prove that the programme should be cancelled. What it demonstrates is that the continuing economic case cannot simply be assumed because a strategic decision was made several years ago.
EDF is therefore asking Ofgem and NESO for a transparent strategic review of forthcoming Pathway to 2030 investments. It wants updated cost information, updated generation assumptions and clearer evidence of the value-for-money case supporting individual projects. It has also called for a live public tracker showing construction progress and project costs.
Given the sums involved, those requests seem remarkably reasonable. Indeed, the more surprising question is why such information is not already presented to the public in an easily accessible project-by-project format.
Consumers should be able to see what was originally forecast, what the project is expected to cost today, why the project remains necessary, which generation or demand assumptions justify it and when the infrastructure is genuinely expected to be operational.
Without that level of transparency, the public is effectively being asked to fund a transformation whose individual economic assumptions are extremely difficult to examine.
THIS IS WHY “BRITAIN REPLANNED” MATTERS
The argument we have been developing through Britain Replanned has never needed to claim that every transmission project is unnecessary. That would be both unrealistic and technically weak. Britain requires a reliable and modern electricity network, and parts of the existing system unquestionably require investment.
Our concern has always been about the sequence through which Britain’s transformation has been taking place.
Political targets establish the desired future energy system. High-level models then estimate generation and demand patterns needed to achieve that destination. Those assumptions generate predicted electricity flows, which in turn produce network requirements. Network requirements become strategic investment programmes, and those investment programmes eventually become individual substations, overhead lines, converter stations, cable corridors and offshore connections.
Only when those individual projects begin moving through detailed development does much of the physical reality become fully apparent. Geological surveys are carried out, landowners become involved, environmental constraints emerge, access requirements are identified, construction methodologies develop, supply-chain problems become clearer and detailed engineering begins replacing earlier strategic assumptions.
Reality can then force changes.
Routes move. Costs rise. Timetables slip. Connection dates change. Generators are delayed. Planning becomes more complicated. Supply-chain pressures affect transformers, switchgear and cables. One project can become dependent upon another whose own delivery programme has already moved.
None of that proves conspiracy or incompetence. Large infrastructure is inherently difficult.
But it does create a critical governance issue. If the evidence underneath the programme changes, how often is the overall strategic case revisited?
There is a danger in continually redesigning individual projects while treating the original strategic destination as effectively untouchable. Eventually the programme can become self-reinforcing: infrastructure is justified by targets, targets are justified by modelling, and further infrastructure is then justified because previous infrastructure has already been approved.
That is why EDF’s intervention is so significant. A major participant in the energy industry is now arguing that changing costs, changing generation assumptions and changing delivery dates justify another strategic look at the programme.
NESO ITSELF IS ALREADY REASSESSING THE FUTURE
There is further evidence that strategic network planning can and does evolve.
In June 2026, NESO published its Beyond 2030 Electricity Transmission Update. That work reflects changes in national policy, Future Energy Scenarios, connections reform and proposals brought forward by the Transmission Owners. NESO used updated evidence to reconsider system need, timing and value for money, ultimately recommending 43 network projects for development for delivery during the 2030s while leaving other longer-term options requiring further assessment.
That is an important precedent because it demonstrates that network planning is not immovable. Assumptions can be updated, projects can be reconsidered, timing can be reviewed and value for money can be reassessed as new evidence emerges.
If that discipline can be applied to infrastructure required beyond 2030, there is every reason for the same approach to be applied transparently to the Pathway to 2030 programme where material circumstances have changed since the original design was produced.
THE FINANCIAL SCALE IS BECOMING IMPOSSIBLE TO IGNORE
The history of these programmes illustrates how rapidly the scale of the transformation has developed. Pathway to 2030 was associated in 2022 with up to £54 billion of network investment. Beyond 2030 subsequently identified around £58 billion of further direct network investment. Clean Power 2030 analysis later suggested that delivering the transmission network required to 2030 could involve up to £60 billion, including approximately 1,000 kilometres of new onshore network and more than 4,500 kilometres of offshore network and enabling works.
EDF now points to more recent NESO publications identifying approximately £89 billion of further transmission projects potentially completing from 2031 onwards.
Once again, these are not figures that can responsibly be placed into a calculator and presented as one single total. They relate to different stages of the network, changing estimates and overlapping programmes. But collectively they reveal the sheer scale of the undertaking.
Britain is not making a few incremental improvements to its electricity network. It is attempting one of the most extensive transformations of the system in modern history, with costs ultimately flowing through to households and businesses.
That makes scrutiny essential rather than optional.
REVIEW BEFORE THE COST BECOMES IRREVERSIBLE
There is another part of EDF’s intervention that deserves particular attention. EDF observes that only a limited number of the major schemes within Ofgem’s Accelerated Strategic Transmission Investment programme have yet received full funding. Its argument is that there remains an opportunity to reassess parts of the programme before substantially larger sunk costs are created.
That point is difficult to dispute. If strategic circumstances have changed, the most financially responsible moment to reassess the programme is before billions more have been irrevocably committed.
No sensible household would continue with a major construction project without reviewing the budget when the costs had doubled. No responsible company would continue an investment programme without revisiting its business case when the expected customers or timetable had materially changed.
National infrastructure should not be subject to a lower standard simply because the numbers involved are so large that they become difficult for the public to comprehend.
A review does not mean stopping everything. It means identifying which projects remain essential, which require modification, which should be delayed and whether any no longer offer sufficient value.
THIS IS NOT AN ARGUMENT FOR DOING NOTHING
There will inevitably be attempts to portray scrutiny of the programme as opposition to electricity infrastructure itself. That would be a serious misunderstanding of the issue.
Britain needs a robust electricity grid. Demand is changing, industrial requirements are evolving, data centres are creating new concentrated loads, existing infrastructure is ageing and bottlenecks within the present system already impose substantial balancing costs.
NESO has repeatedly warned about the consequences of failing to reinforce key parts of the transmission system. Therefore, the real choice is not between building everything currently proposed and building nothing.
The choice is between building intelligently and building automatically.
A modern transmission network should be based on current engineering evidence, realistic generation forecasts, credible connection dates, actual project maturity, up-to-date construction costs and demonstrable consumer benefit. A programme devised under older assumptions should not be protected from review merely because enormous amounts of work have already gone into designing it.
Infrastructure must serve the energy system. The energy system should not be forced to justify infrastructure simply because that infrastructure has already entered the programme.
THE PUBLIC DESERVES TO SEE THE EVIDENCE
Ultimately, this debate comes down to transparency and accountability.
Britain’s landscape and electricity system are being transformed through new pylons, substations, converter stations, cable corridors, generation zones and offshore infrastructure. Communities are being asked to host those developments, while households and businesses are expected to finance the networks through electricity charges for decades to come.
Yet EDF is now saying there is insufficient publicly available information to determine authoritatively whether the original Pathway to 2030 network remains the best approach.
That should concern people regardless of their position on Net Zero, renewable generation or party politics. If consumers are paying for infrastructure, consumers are entitled to know the assumptions that justify it.
They should be able to see the original estimated cost and the latest estimated cost. They should be able to see the generation projects whose connections justify each reinforcement. They should be able to see contractual connection dates alongside credible construction and energisation dates. They should be able to understand the dependencies between projects and, above all, they should be shown why the expected consumer benefit remains greater than the cost.
This should not be controversial. It is basic financial and democratic accountability.
THE PLAN MUST NOW BE TESTED AGAINST REALITY
The important question facing Britain is no longer whether investment in the electricity network is necessary. It clearly is. The question is whether the enormous transmission programme developed several years ago remains the most efficient and economically defensible way of delivering that investment under today’s circumstances.
EDF has now placed that question firmly into the public debate. Ofgem and NESO should respond with evidence rather than reassurance.
The generation assumptions should be updated. Current project costs should be published. Realistic construction and energisation dates should be made available. Dependencies between projects should be clearly identified, and the value-for-money case for each major reinforcement should be capable of public examination.
If the projects still stand up to that scrutiny, then the evidence will strengthen the case for building them. If circumstances have changed sufficiently that some no longer do, Britain should have the courage to change course before still more money is committed.
That is not opposition to Britain’s electricity grid. It is exactly the level of scrutiny that a programme of this scale should have attracted from the beginning.
For years, households and communities have effectively been told that this transformation simply has to happen and that the network must therefore be built around it. EDF’s intervention suggests that a far more important question is finally beginning to emerge from inside the energy industry itself.
Does the plan still add up?
Before Britain commits tens of billions more and passes the cost through to consumers, the public deserves a proper answer.
SOURCES
EDF Energy, Transmission costs: the need for greater transparency and strategic review, 19 August 2026.
https://www.edfenergy.com/about/an-electric-britain/transmission-costs-need-greater-transparency-and-strategic-review
Ofgem, RIIO-3 Final Determinations for the Electricity Transmission, Gas Distribution and Gas Transmission sectors, December 2025.
https://www.ofgem.gov.uk/decision/riio-3-final-determinations-electricity-transmission-gas-distribution-and-gas-transmission-sectors
National Energy System Operator, Pathway to 2030, July 2022.
https://www.neso.energy/news/eso-publishes-pathway-2030-major-step-deliver-50gw-offshore-wind-2030
National Energy System Operator, Beyond 2030: A national blueprint for a decarbonised electricity system in Great Britain, March 2024.
https://www.neso.energy/document/304756/download
National Energy System Operator, Clean Power 2030 — Networks, connections and network access analysis.
https://www.neso.energy/document/346796/download
National Energy System Operator, Beyond 2030 Electricity Transmission Update, June 2026.
https://www.neso.energy/publications/beyond-2030
Shane Oxer. Campaigner for fairer and affordable energy
SAY NO TO THE DESTRUCTION OF OUR LAND 
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