This week in UK data centres:
- Britain’s flagship AI data centre cannot get the power to switch on
- Behind-the-meter solar is accelerating — but comes with constraints the market is only beginning to understand
- National Grid’s own investment arm is backing US power infrastructure for AI data centres
The flagship has no plug. Nscale’s £2bn Essex data centre cannot get grid power.
Nscale’s £2bn Essex data centre has planning permission, Nvidia backing, and Microsoft as anchor tenant. What it does not have is power, after National Grid said it could not connect the site in time. clydeco
The project at Loughton, Essex was announced by the Prime Minister during Donald Trump’s UK state visit and positioned as a centrepiece of Britain’s AI infrastructure ambition. It is designed to support 50MW of AI and HPC capacity, scaling to 90MW, and could house up to 45,000 Nvidia GB200 GPUs. The initial opening date of late 2026 was already missed due to planning delays. Now it is the grid that is holding up delivery, and the power is unlikely to arrive in time for the planned 2027 opening. Savills
Nscale is in discussions with California-based Bloom Energy to provide electricity through solid oxide fuel cells instead of waiting for the permanent grid connection. Bloom Energy has already deployed similar systems at a data centre in Manchester and at the Wytch Farm oilfield in Dorset, and has a deal to provide the technology to 19 Equinix data centres globally. Demand for the technology has surged because of the AI boom, sending Bloom’s share price up 800% in the past year. businesswireSavills
The clear lesson for data centre operators is that grid availability cannot be treated as a final construction milestone. Instead, it should be one of the earliest strategic considerations in site selection, investment planning, and customer commitments. armason
The Nscale story is not an isolated failure. Data from Sightline Climate suggests 26% of data centre capacity was delayed in 2025. It estimates that 30 to 50% of the global data centre capacity expected for 2026 could be delayed due to power constraints, equipment shortages, or local opposition. More than 100 UK projects have now said they will turn to gas as connection backlogs stretch to a decade or longer. Nscale is the most publicly visible example of a problem that is playing out across the entire UK pipeline. businesswireCBRE UK
If data centres fail to deliver compute capacity by an agreed date, they can sometimes be required to compensate their customers for the delays. With Microsoft signed up as anchor tenant, the commercial pressure to bridge the gap is acute. The retreat to Bloom Energy fuel cells is not a preference — it is the least bad option available to a project that has run out of time on the grid queue. businesswire
Sources: The Next Web — Nscale’s £2bn data centre can’t get grid power | Sifted — Nscale’s £2bn UK data centre hit by grid delays | Data Centre Review — Nscale’s £2bn Essex data centre hit by grid delays | Data Centre Magazine — What are the factors delaying Nscale’s investment?
Behind-the-meter solar is accelerating. The constraints are real.
More than 125GW of planned energy and data centre projects are stuck waiting for a connection to the National Grid. Data centre operators that wish to progress more quickly have been striking private deals — also known as behind-the-meter deals — with energy generators to get a direct, off-grid connection. Operators are following an increasing trend to look for innovative ways of shoring up power, whether as permanent baseload or as an interim measure, by striking private deals with energy sources such as solar farms or gas turbines to ensure a direct, off-grid connection. SQ Magazine
The UK solar market is expected to grow by 5 to 5.5GW in 2026, a 50% year-on-year increase for the second consecutive year. Around 80% of data centre electricity demand will come from AI data centres by 2060 according to the World Economic Forum, with potential energy demands of 6,400TWh per year. Behind-the-meter solar is appealing because it can reduce dependency on the grid queue, deliver renewable credentials, and in some configurations lower the total cost of power over the life of a facility. ALM Corp
But the constraints are significant and underappreciated by many in the market. Behind-the-meter PV will often not meet the entirety of a data centre’s demand, and deploying a project that aims to meet all of an offtaker’s demand — rather than one that is part of a more complex energy supply arrangement — involves fundamentally different challenges. “It won’t just be the private wire solution, you have to build on that and look at your whole energy supply arrangement.” ibisworld
The design, approval and construction of private wire solar assets can take many years and involve multiple planning and regulatory bodies, especially as the cables need to avoid major obstacles such as roads, rivers, and other landowners. If they do need to cross other people’s land, permissions are required, which takes time and money and can trigger regulatory changes. And the supply chain is its own constraint: more advanced components and greater ESG scrutiny within the European supply chain mean new technology faces more complex delivery environments where manufacturers face competing demand. ALM CorpALM Corp
The honest picture is that behind-the-meter is a meaningful part of the solution for the UK data centre power problem — but it is not a quick fix, it will not fully substitute for a grid connection in most configurations, and it introduces its own planning, regulatory, and supply chain complexity that developers are only beginning to fully understand.
Sources: Computer Weekly — Datacentres need to consider alternatives to grid connection | Solar Power Portal — Behind-the-meter solar powers UK data centres amid grid delays | Solar Power Portal — Data centres drive demand for behind-the-meter power in the UK
National Grid is investing in the US power infrastructure it cannot provide domestically.
National Grid is investing £1.4bn for a 35% stake in Joulent, a US platform building power infrastructure for AI data centres. The strategic logic is straightforward — Joulent operates in a market where power and AI infrastructure are being built at pace, and the investment gives National Grid exposure to the economics of that build-out. CBRE UK
The irony is pointed. National Grid’s domestic grid cannot connect Nscale’s Essex facility in time for its 2027 opening. National Grid’s investment arm is backing US AI power infrastructure. The Great Grid Upgrade, worth £28 billion, aims to strengthen and expand the UK network, but this complex process takes time. The demand for power is rapidly increasing with no meaningful way of deciding which projects are and are not viable in the interim. SQ Magazine
As Britain’s electricity network comes under pressure from AI demand and wider electrification, operators are being forced to rethink how new campuses are designed and delivered. Grid availability cannot be an afterthought — it must be the first question in site selection, not the last. armason
Sources: Results Sense — Nscale’s £2bn UK data centre stalled by grid delays | Computer Weekly — Datacentres need to consider alternatives to grid connection | Data Centre Magazine — What are the factors delaying Nscale’s investment?
The week in one line: Britain’s flagship AI data centre cannot get the power to switch on, behind-the-meter solar is accelerating but is not a simple substitute, and National Grid is investing in US AI power infrastructure while its domestic network cannot connect a £2bn project in Essex.
Armason tracks infrastructure signals across the UK and European data centre market. For site availability, grid intelligence, or pipeline advisory, visit armason.co.uk
