A queue is supposed to establish order.
It takes a group of competing claims and arranges them into a sequence. Those at the front move first. Those behind them wait. The mechanism works only while position retains a meaningful relationship with progress.
Great Britain’s electricity connection queue gradually lost that relationship.
By mid-2025, more than 738 gigawatts of generation and storage capacity was waiting to connect to the electricity network. The queue had expanded tenfold in five years and contained roughly four times the generation capacity considered necessary for the government’s 2030 clean-power objectives. Some projects capable of proceeding were being offered waits of up to ten years.
The problem was not simply that the queue had become long.
It was that a project’s position no longer reliably indicated whether it possessed land, planning consent, finance, technical maturity or a realistic probability of being built. Projects that were ready could sit behind projects that were not. Capacity could be reserved for developments that might never progress, while more viable projects waited for network space to be released.
The queue remained administratively ordered.
Operationally, it had become misleading.
Erths assessment: The central failure was not excess demand alone. It was the collapse of the relationship between queue position, project readiness and system need.
1. What was the queue supposed to do?
New power stations, solar farms, wind farms, battery installations, interconnectors and large electricity users cannot simply attach themselves to the network.
A developer must apply for a connection. Network operators then assess where and when the project can connect, what infrastructure must be constructed or reinforced, and how the project will affect the wider electricity system.
Under the previous model, projects were generally prioritised according to when they accepted their connection offer. In principle, this created a neutral first-come, first-served sequence.
That method was understandable when the number of applications was manageable and most applicants had a reasonable prospect of proceeding.
It became less effective as the energy system changed.
The expansion of renewable generation, battery storage, electrification and speculative project development produced far more proposed capacity than the network could accommodate or the country was likely to require within the stated timescales.
The rules still treated acceptance of a connection offer as the organising event. But accepting an offer did not necessarily mean that a developer had secured planning permission, committed finance, obtained land rights or reached the stage at which construction could begin.
Chronological priority became a substitute for evidence of delivery.
2. The queue began measuring applications rather than projects
Every proposed development represented a claim on future network capacity.
Some claims were attached to mature projects. Others were exploratory, commercially uncertain or dependent on approvals that had not yet been secured. Yet once entered into the process, they could still affect the dates and infrastructure assumptions applied to projects behind them.
This produced two different queues occupying the same administrative structure:
- A queue of recorded connection agreements.
- A much smaller, less visible queue of projects with a realistic probability of being built.
The system had extensive information about the first and insufficient confidence about the second.
That distinction is important. A 738GW queue did not mean that Great Britain was preparing to construct 738GW of additional generating capacity. It meant that applications representing that volume had secured positions within the connection process.
The headline number therefore combined several different things:
- credible projects approaching delivery;
- early-stage projects still seeking permission or finance;
- projects competing for the same commercial opportunity;
- technologies concentrated in places where network capacity was limited;
- projects unlikely to proceed within their contracted timetable;
- capacity that exceeded strategic expectations for particular technologies.
The number was accurate as a count of contractual claims.
It was increasingly inaccurate as a forecast of likely infrastructure.
This is the defining characteristic of Measurement Breakdown: the metric continues to be calculated correctly after its relationship with the underlying reality has weakened.
3. Administrative order concealed physical impossibility
Ofgem’s assessment exposed the scale of the mismatch.
It found that 213GW of projects had connection offers dated before the end of 2030. Delivering all of them on schedule would have required a connection rate more than five times the historical average of approximately 8GW per year. Ofgem did not consider that feasible.
The dates therefore created an appearance of scheduled delivery that the historical rate of connection could not support.
Connection offers for both generation and demand were extending into the 2040s. The queued mix was also misaligned with the technology ranges considered necessary for a secure and operable 2030 electricity system. Batteries and solar projects were particularly oversubscribed in some areas, while other technologies risked being undersupplied.
None of this meant that every project was fictitious or deliberately speculative.
It meant that the system could not reliably distinguish, early enough, between several categories of claimant. A project could be commercially serious and still fail. It could possess land but not finance, planning consent but not equipment, or technical readiness without a viable route through the network.
A first-come system treated these uncertainties as matters to be resolved later.
As the queue expanded, “later” became the source of the blockage.
4. Why the distortion mattered
A congested connection queue does more than delay individual developers.
It changes how the wider system is planned.
Network companies must decide where substations, transmission lines and reinforcements will be required. If the project pipeline contains large volumes of uncertain or duplicative capacity, planners face a choice between two risks:
- building infrastructure for projects that never materialise; or
- withholding investment until the project pipeline becomes clearer.
The first risks unnecessary cost. The second risks delaying viable generation, storage and industrial development.
The queue also influences investment decisions. A developer receiving a distant or uncertain connection date may delay expenditure, seek another location or abandon the project. Investors cannot treat a connection offer as a dependable schedule if projects ahead of it may disappear, move or fail to satisfy their milestones.
This allows a self-reinforcing pattern to form:
Uncertain projects enter the queue → the queue creates uncertain network assumptions → connection dates become less credible → viable projects face greater uncertainty → developers submit more options to preserve future access.
A mechanism intended to coordinate investment can therefore encourage additional defensive applications.
The queue does not merely record uncertainty. It begins to produce it.
5. The structural drift
The original objective of the connection process was to allocate access fairly and coordinate the infrastructure required to connect customers.
Over time, its practical function changed.
It increasingly became a system for reserving future optionality.
For an individual developer, entering early could be rational even if the project was not ready. Waiting until every commercial and planning condition had been resolved might mean losing years in the connection sequence.
The rational action for each participant—apply early and preserve a position—produced an irrational aggregate outcome.
This is Structural Drift.
The formal purpose of the system remained unchanged. Its incentives gradually pushed behaviour away from that purpose.
The distinction matters because the failure cannot be attributed only to irresponsible applicants. Developers were responding to the rules presented to them. When early entry is rewarded and uncertainty carries insufficient cost, speculative participation becomes a predictable feature of the system.
The queue did not become distorted despite its incentives.
It became distorted through them.
6. From “first come” to “ready and needed”
In April 2025, Ofgem approved the TMO4+ reform package.
The new process replaced simple chronological priority with criteria intended to establish whether a project is both:
- sufficiently ready to proceed; and
- aligned with identified strategic need.
Projects meeting the requirements can receive Gate 2 status, which provides a confirmed connection point, date and queue position. Projects that do not meet the Gate 2 criteria are placed at Gate 1. Gate 1 does not reserve capacity, provide a firm queue position or guarantee a connection, although projects may reapply through future application windows.
Readiness is assessed through evidence such as project progress, land rights and planning status. Strategic alignment is determined through national capacity pathways, protections for certain advanced projects and limited powers to designate projects serving wider system requirements.
The reform therefore changes what the connection process measures.
Under the old system, the organising fact was when an offer had been accepted.
Under the new system, the organising facts include readiness, technology, location, delivery phase and alignment with strategic energy plans.
This should produce a pipeline that is more useful for network planning than a purely chronological queue.
It also represents a significant transfer of discretion.
A first-come system may generate poor outcomes, but its ordering rule is comparatively simple. A ready-and-needed system requires institutions to decide:
- what counts as sufficient readiness;
- how evidence should be weighted;
- which technologies are required;
- how much capacity is permitted in each region;
- which projects deserve protection;
- when strategic designation should override ordinary criteria.
Ofgem acknowledged stakeholder concerns that NESO’s discretion could reduce transparency, while concluding that some bounded discretion was necessary.
The reform therefore exchanges one form of risk for another.
It reduces the risk that chronological position protects undeliverable projects. It increases the importance of institutional judgement, data quality and strategic forecasting.
7. What the reordering achieved
In December 2025, NESO announced the first major results of the reformed process.
Approximately 283GW of generation and storage projects were identified to move forward:
The pipeline also included almost 100GW of new or expanded transmission-connected demand. More than 300GW of projects from the previous queue did not move forward at that stage, either because they were not ready, were not aligned with the relevant capacity pathways, did not apply, or selected a Gate 1 outcome.
The detailed results show the scale of active selection.
By April 2026, government and Ofgem reported that 221GW of projects holding firm connection agreements had been moved out of the main queue because they were not required by 2035 or were no longer progressing. Additional projects had voluntarily moved to Gate 1, meaning the total filtered capacity was higher.
The queue became smaller and more selective.
That is meaningful progress.
But it is not yet evidence that connections have become materially faster.
Reclassification is an administrative outcome. Delivery is a physical one.
8. Reform met the constraints the queue had concealed
Once the pipeline had been reordered, NESO and the network companies still had to convert queue outcomes into technically credible connection offers.
That process encountered delays.
Historic connection agreements contained data errors. Network assumptions had to be updated. Engineering studies had to be rerun in areas where the volume or type of Gate 2 projects differed from previous expectations. Government and Ofgem publicly stated in April 2026 that further slippage was unacceptable.
- Phase 1 transmission and large embedded offers: through mid-September 2026;
- Phase 1 distribution offers: through mid-November 2026;
- Phase 2 transmission and large embedded offers: through mid-January 2027;
- Phase 2 distribution offers: through mid-March 2027.
This does not prove that the reform failed.
It demonstrates that the queue was only one layer of the constraint.
Removing weak projects does not automatically:
- construct new transmission lines;
- increase engineering capacity;
- accelerate planning decisions;
- procure transformers, cables and switchgear;
- resolve local network limitations;
- eliminate errors inherited from previous agreements;
- guarantee that selected projects reach construction.
The queue could be reorganised through policy and contract changes. The electricity network must still be expanded through physical work, regulated investment and planning consent.
This is Reform Constraints: intervention can correct the allocation mechanism without immediately correcting every dependent system.
9. The distortion moved to the demand side
The most revealing development came after the generation and storage queue had been reordered.
Demand projects—such as data centres and other large industrial users—had not originally been restricted by the same strategic capacity limits. Policymakers wanted to support economic growth and electrification rather than cap legitimate new demand.
That created a new opening for speculative claims.
On 29 July 2026, Ofgem reported that demand connection applications had surged from 41GW to 125GW in less than a year, with data centres accounting for at least 80GW. It opened consultation on commitment fees and new progress milestones intended to encourage less viable projects to leave the queue.
This is not a separate problem.
It is the same structural incentive appearing in another part of the system.
Where access to future network capacity is scarce and commercially valuable, participants have an incentive to reserve it before they can prove they will use it. Tightening the rules for one class of applicant can shift speculative behaviour into another class if the underlying value of early reservation remains.
The system therefore illustrates a broader principle:
Filtering the queue does not remove the incentive to manufacture optionality. It changes where that incentive appears.
Generation reform may have produced a more credible supply pipeline while leaving demand-side applications exposed to similar inflation.
This is why the success of the reform cannot be judged by one headline reduction in queued capacity.
The relevant question is whether the entire connection system now distinguishes credible demand from strategic reservation more effectively than before.
The Erths framework
Measurement Breakdown
Queue position ceased to function as a dependable indicator of readiness.
The queue’s total capacity remained an accurate measure of applications and agreements, but became an unreliable measure of projects likely to connect. Contracted dates also exceeded historically achievable connection rates.
The measurement was not false.
Its implied meaning had failed.
Structural Drift
The connection process moved from coordinating deliverable projects to preserving developer optionality.
Early application was individually rational because future access was scarce. The accumulation of those decisions weakened the queue for everyone.
The system’s behaviour drifted away from its stated purpose without a formal change in that purpose.
Hidden Instability
For a period, the queue looked orderly because every project possessed a position and nominal date.
The instability was concealed inside assumptions about which projects would progress, which infrastructure would be built and whether contracted dates were technically achievable.
Administrative precision masked delivery uncertainty.
Reform Constraints
Gate 1 and Gate 2 can improve selection and release capacity held by weaker projects.
They cannot independently accelerate planning, construction, equipment supply, engineering studies or every network reinforcement required to deliver the selected pipeline.
A better queue does not itself create a bigger grid.
Sudden Collapse
This is not primarily a Sudden Collapse case.
The connection process did not fail through a single abrupt breakdown. It deteriorated through accumulation. However, the system risked abrupt investment consequences if developers ceased to believe their connection dates or if strategically important projects became unable to proceed within policy timescales.
The visible crisis arrived late. The structural deterioration occurred much earlier.
Signals to watch
The reform should be judged through delivery rather than announcement.
1. Actual connection dates
Do Gate 2 projects connect materially earlier than comparable projects under the previous system, or do dates continue to move after offers are issued?
2. Milestone enforcement
How many Gate 2 projects fail readiness or progression milestones, and how quickly is their capacity released to other projects?
3. Network construction
Are transmission and distribution reinforcements completed quickly enough to support the prioritised pipeline?
4. Pipeline replacement
When projects leave Gate 2, can ready replacements enter without recreating years of uncertainty?
5. Demand-queue growth
Do commitment fees and progression requirements reduce speculative data-centre and industrial applications, or does demand continue to expand faster than credible delivery?
6. Technology concentration
Does the prioritised pipeline retain excessive concentrations of batteries, solar or particular demand types despite strategic capacity ranges?
7. Institutional discretion
Are designation, protection and strategic-alignment decisions published clearly enough for developers and investors to understand why one project advanced and another did not?
8. Repeated timetable revisions
Do the revised offer dates hold, or does administrative reordering continue to expose unresolved data and engineering problems?
What would change the assessment?
The Erths assessment would improve if the reformed process produced:
- shorter realised connection times;
- fewer projects holding capacity without progressing;
- more reliable offer dates;
- faster replacement of failed projects;
- clearer network-planning assumptions;
- transparent and predictable strategic decisions;
- a demand queue tied more closely to evidence of financial and operational commitment.
The assessment would weaken if the queue became smaller on paper while:
- physical connection rates remained broadly unchanged;
- offer dates continued to slip;
- selected projects failed at similar rates;
- speculative capacity migrated between generation, storage and demand;
- strategic discretion became difficult to scrutinise;
- network construction remained the dominant unresolved bottleneck.
The decisive evidence will not be the number of gigawatts removed.
It will be the number of viable projects connected.
Conclusion
Great Britain’s electricity connection queue did not fail because it lacked rules.
It failed because the rules continued to produce orderly outputs after those outputs had lost much of their practical meaning.
A project could possess a place, a capacity allocation and a date without possessing a credible path to delivery. The queue measured contractual sequence more effectively than physical readiness.
The TMO4+ reforms directly confront that failure. They replace chronological priority with an evidence-based and strategically managed pipeline. The removal or downgrading of hundreds of gigawatts has produced a more plausible picture of what the system may actually need and build.
But the reform also reveals the limits of administrative correction.
The selected projects still depend on network construction, planning, engineering, equipment, finance and institutional execution. Data problems have already delayed parts of the offer programme. Meanwhile, speculative pressure has begun to reappear in the rapidly expanding demand queue.
The old queue asked:
Who arrived first?
The new process asks:
Who is ready, and which projects does the system need?
That is a better question.
Whether the institutions responsible can answer it accurately—and then deliver the infrastructure implied by their answer—remains unresolved.
