For UK data-centre development, access to power has become one of the defining constraints on growth. But the next phase of the market may be shaped by a more demanding question: not simply whether a project has a grid connection, but whether that power can credibly be converted into an energised, commercially viable data centre.
That distinction is becoming more important as Britain's electricity connections regime moves towards tighter tests of project viability and progression.
Ofgem's July 2026 proposals for data-centre connections are the clearest indication yet of this shift. The regulator is considering a commitment fee for larger projects alongside data-centre-specific milestones requiring evidence of commercial, technical and financial progress. The proposals are not yet final policy, but their direction is significant.
For developers and capital providers, the implication is broader than queue reform. A connection offer remains valuable, particularly in a power-constrained market. But on its own, it may increasingly say less about the ultimate investability of a development.
The queue has outgrown the value of a connection position alone
The scale of the issue is striking.
According to Ofgem, contracted demand in the connection queue increased from 41GW in November 2024 to 125GW by June 2025. Around 73GW of that total was attributed to data-centre projects. For comparison, peak electricity demand across Great Britain in 2025 was approximately 45GW. These figures are set out in Ofgem's data-centre connection reform consultation.
Not all of this capacity will be built.
That matters because an overloaded queue does more than create longer connection timelines. If projects without a credible route to delivery retain network capacity, the queue becomes a weaker indicator of real future demand. It can distort network-planning signals while slowing projects that are capable of progressing.
Ofgem's proposed response is therefore aimed not simply at reducing the queue, but at differentiating between projects.
Under the current proposals, data centres above a 40MW threshold would be required to secure a financial commitment from acceptance of a connection offer through to energisation. Ofgem is consulting on a fee equivalent to 2.5%–7.5% of average data-centre capital expenditure, estimated at approximately £237,500–£712,500 for each MW of requested capacity. The commitment would be returned where a project progresses in accordance with the rules and could be forfeited where it does not.
The proposed fee is material. But the more strategically important part of the reform may be the accompanying progression requirements.
Viability is being defined more broadly
Ofgem's proposed queue-management framework would require relevant data-centre projects to demonstrate tangible evidence of development progress.
The proposed requirements include a credible compute customer or end-user, procurement of long-lead electrical equipment, financial capability and technical readiness. Ofgem has also proposed different pathways for self-operated facilities and projects intended for lease or sale, recognising that commercial development models differ across the sector. Projects that fail to satisfy the requirements could ultimately lose their queue position.
This is a meaningful change in how grid capacity could be treated.
Historically, a connection offer could itself carry substantial strategic value. In a constrained market it could support land value, attract capital or underpin discussions with operators and prospective buyers.
That value will not disappear. But the proposed framework points towards a more dynamic concept of connection quality.
A project may increasingly need to demonstrate not only that network capacity has been allocated to it, but that the development behind that capacity is advancing towards actual use.
In practical market terms, commercial readiness and power readiness are beginning to converge.
From nominal megawatts to deliverable power
For investors, operators and strategic partners assessing data-centre developments, headline connection capacity has never been the whole story. Connection date, planning position, site control, technical design, capital requirements and customer strategy already influence the quality of an opportunity.
The direction of UK reform makes those distinctions harder to ignore.
Two projects may each hold a connection offer for the same number of megawatts, yet have very different risk profiles.
One may have a credible energisation programme, advanced planning, demonstrable financial capacity, technical procurement underway and a clear commercial route to occupancy or ownership. Another may have little beyond land and a queue position.
On paper, both have power.
Economically, they do not have the same asset.
This is where the concept of deliverable power becomes increasingly useful. It is not a regulatory definition. Rather, it describes the combination of network capacity, timing and project maturity required to turn an electrical connection into usable infrastructure.
As connection regimes become more demanding, the value distinction between nominal MW and deliverable MW is likely to become more visible.
That does not mean every advanced project should command a particular valuation premium, nor that early-stage connection positions cease to have value. Valuation will remain project-specific.
But it does suggest that connection capacity should increasingly be considered together with the credibility of the development sitting behind it.
The change extends beyond queue curation
The Curate proposals sit within a wider restructuring of how Great Britain approaches large electricity-demand connections.
Government has separately consulted on mechanisms to prioritise strategically important demand, including data centres, rather than relying solely on the existing queue sequence. Ofgem's broader connections review is moving ahead with programmes intended to improve the quality and transparency of connections data and strengthen standards and accountability around delivery.
A further consultation launched by Ofgem on 7 October 2026 proposes expanding the ability of demand, generation and storage customers to self-build certain transmission connection assets before transferring them to the relevant transmission owner. The detail remains under consultation, but the strategic direction is notable: connecting customers may gain greater ability to influence the physical delivery of their own connections rather than relying entirely on the traditional delivery route.
Taken together, these measures point to a connections market becoming more actively managed on both sides.
Projects may face stronger requirements to demonstrate that they deserve to retain scarce capacity, while viable projects may gain new mechanisms to progress connections more quickly.
That combination matters for capital.
Scarcity remains a source of value, but scarcity alone is an increasingly incomplete investment thesis.
A more differentiated UK development market
The strongest consequence of these reforms may therefore be greater differentiation between data-centre projects.
Until recently, the scarcity of grid access encouraged the market to place considerable emphasis on whether capacity had been obtained at all. In the next phase, the question is likely to become more granular: what exactly sits behind that connection, how credible is the route to energisation, and how far has the commercial development progressed?
This should favour neither developers nor investors automatically. It raises the standard of evidence on both sides.
For developers, connection capacity that is supported by a credible project may become more distinguishable from speculative capacity.
For investors and strategic partners, the challenge is to look beyond the headline MW figure and understand how much of the project's apparent power advantage can realistically translate into operational infrastructure.
And for the wider market, a healthier queue should ultimately provide a more reliable signal of where real data-centre demand is likely to emerge.
The final design of Ofgem's data-centre reforms still matters, and the July proposals should not be treated as settled policy. But the direction is already becoming clear.
A grid connection remains a scarce and strategically important development asset. Increasingly, however, the more valuable distinction may be between projects that have power on paper and those that can demonstrate a credible route to delivering it.