Global Storage Is Booming. Your Grid Connection Isn't.

The numbers landed this week and they are genuinely striking. Global energy storage installations grew by 61.3% in 2025. Battery energy storage system shipments surged 75.5% to 421.2 GWh, with 600 GWh projected for 2026. Balkan Green Energy News The Balkan Green Energy News piece reporting this frames AI data centre demand as the force that will sustain the trajectory. The IEA, BloombergNEF, and InfoLink are all pointing in the same direction. It reads, at first pass, like unambiguous good news for anyone developing commercial solar and storage in the UK.

It is not. Or rather — it is good news for the right people, which is a much narrower group than the headlines suggest. For UK C&I developers and commercial operators, the global surge in storage tells you something important about where technology costs are heading and almost nothing about whether your project is deliverable.

What the Surge Is Actually Measuring

The 61.3% figure is a global shipments number. It includes Chinese manufacturers who dominate all six of the world's largest cell supplier positions — CATL, HiTHIUM, EVE Energy, BYD, CALB and REPT BATTERO — and whose export revenues for energy storage and EV batteries exceeded $65 billion in 2025. Modern Diplomacy It includes utility-scale deployments in the US, Middle East, Chile, and Japan. It includes data centre co-location plays in markets where grid access is less constrained than Britain's.

The data centre angle is real: AIDC energy storage shipments are projected to reach 61GWh by 2027, a 114% year-on-year increase, driven by data centres' core requirements of full-duration supply, high reliability, and cost efficiency. Energy-Storage.News But co-locating storage with a data centre requires a grid connection for that data centre first — and in the UK, data centres currently face lead times of five to ten years for connection, with some facing dates as far into the future as the 2030s. Data Center Dynamics

The coverage does not address this. It rarely does.

The Grid Reality That Doesn't Make the Headlines

This section is non-negotiable in anything we write. Not because it is a talking point, but because it is the single most commercially relevant fact for any UK developer reading a positive global storage story.

The UK connections queue stands at over 738 GW, against the 200–225 GW of clean generation capacity required by 2030. National Energy System Operator NESO's connections reform, approved by Ofgem in April 2025 and delivering results in December, restructured that queue substantially. Around 3,000 applications were assessed, with 283 GW of projects moving forward into a new delivery pipeline. National Energy System Operator That sounds like progress — and in structural terms, it is. But the reform also exposed something uncomfortable for the storage sector specifically.

Battery storage received Gate 2 status for 83 GW of projects — an overshoot of approximately 60 GW against what the system actually needs. Knight Frank That means battery storage, as a standalone UK play, is now one of the most crowded positions in an already crowded queue. Developers who assumed their project would benefit from the global storage boom without checking their specific grid position are now finding out what that assumption costs.

Meanwhile, the constraint problem that storage is supposed to solve continues to worsen. Curtailment in Great Britain jumped 22% year-on-year to 10 TWh in 2025, with the total cost of replacing curtailed wind surging past £1 billion. Sustainability Magazine The £1.46 billion headline figure breaks down as £380 million in turn-down payments to wind farms and £1.08 billion for replacement gas-fired generation. Tim Harper The grid is simultaneously generating record volumes of clean energy and paying to switch it off while firing gas plants to compensate. More storage in the wrong location does not fix this. It adds capacity to a system that cannot move the power it is already producing.

What Co-Location Experience Shows

We have worked on enough co-located solar and BESS projects to recognise the pattern that emerges when a client arrives having read a positive global market report and a vendor's revenue stack model. The model looks good. The technology stack is credible. The ambition is right. And then we start asking the questions the vendor did not.

What is the DNO constraint position at the substation? What connection voltage is available and at what timeline? Has the client received a Gate 1 or Gate 2 outcome, and do they understand what that means for their project's deliverability? What happens to the revenue stack if the connection date moves by eighteen months — which, in our experience, is not a tail risk but a planning assumption?

What clients consistently underestimate is the interaction between grid position and revenue model. A BESS project modelled against a DCR or FFR revenue stack looks very different when the available connection capacity limits export. A private wire structure that works at one substation becomes commercially unviable two kilometres away at a different grid entry point. These are not edge cases. They are the norm in our project work.

Independent modelling does not always produce a different answer from vendor modelling — sometimes the project stacks up and the vendor has done the work honestly. But it always produces a more complete answer, because an independent consultant's revenue from a given project does not depend on that project proceeding.

Where the Commercial Logic Holds

We are not anti-storage. We are anti-wishful thinking. There are conditions under which a UK co-located BESS project has a genuinely compelling commercial case, and it is worth being precise about what those conditions are.

Projects with an existing grid connection — whether through a legacy industrial site, a PPA counterparty's infrastructure, or a data centre that has already navigated connection — are in a fundamentally different position from greenfield applicants. For those projects, the global cost curve improvement is directly relevant: cell prices are falling, system costs are following, and the revenue stack from co-location, private wire, and grid services is increasingly bankable.

The revenue stack that works is one that models multiple streams honestly: wholesale trading, FFR, DCR, constraint management where applicable, and private wire margin where a load counterparty exists. No single stream is sufficient. The BESS sizing question — which vendors almost always answer in favour of more capacity — should be driven by the grid connection parameters and the load profile, not by a standard system configuration. Four-hour duration is not always the right answer, and the cases where two-hour or six-hour systems outperform it are more common than vendor proposals suggest.

The Global Context That Actually Matters

The UK's grid constraint problem is not uniquely British. It is the local expression of a global pattern: renewable generation capacity is being built faster than transmission infrastructure, and storage is being deployed as the solution before the grid position of that storage has been properly assessed.

S&P Global's analysis identifies grid modernisation as a key constraint on energy security and competitiveness across all major markets, with AI's surging power demand testing grid limits, revenue models, and sustainability goals simultaneously. S&P Global

In Australia, the AEMO has documented sustained curtailment in South Australia and Queensland as solar penetration has outpaced both transmission and flexible demand. In Germany, curtailment has become the norm, with negative pricing hours increasing as renewable generation outpaces grid capacity — a pattern now replicated across Spain and Italy during spring oversupply periods. Sandstone Group In the US, the Lawrence Berkeley National Laboratory's Queued Up report has consistently shown an active interconnection queue exceeding 2,600 GW, with the majority of projects never reaching commercial operation. Declining lithium-ion battery costs, hitting a record low of $115 per kWh in 2024, have accelerated deployment globally — but that falling cost curve does not resolve the grid access problem that determines whether a project can actually operate. Morgan Lewis

The pattern is consistent: markets that celebrated rapid storage deployment are now confronting the grid reality that global momentum statistics obscure. The UK is not behind this curve. In some respects, with the NESO reforms, it is ahead of it. But the reform has clarified the constraint rather than removed it.

The Right Questions to Be Asking

The question that a developer or C&I operator should be asking after reading this week's global storage numbers is not "how do I access this growth?" It is "what is my grid position, and does it support the commercial model I have been presented with?"

That means starting with a current DNO assessment — not an estimate, an actual position — before committing to a technology specification. It means understanding whether your project is a Gate 2 beneficiary or a Gate 1 applicant, and what that means for your financing timeline and your ability to underwrite a PPA or private wire agreement. It means asking whoever modelled your revenue stack whether they have run the same model against a twelve-month connection delay, a twenty percent reduction in available export capacity, and a wholesale price scenario that includes the negative pricing hours that 2025 delivered in volume.

It means treating the grid as the project — not as the infrastructure problem that someone else will solve before your commissioning date.

Independent Solar Consultants: What We Actually Do

We work with developers, landowners, C&I energy buyers, and investors who want to understand what their project is actually worth before they commit capital to it. Our work sits between the vendor proposal and the final investment decision — independent feasibility, grid connection assessment, revenue stack modelling, PPA and private wire structuring, and project sense-checking from the earliest stage through to financial close.

We have no product to sell and no vendor relationship to protect. That means our analysis reflects what the numbers actually show, not what a particular technology configuration needs them to show. If the project stacks up, we will tell you why and how to strengthen it. If it doesn't, you will find out from us before you find out from the market.

If you are looking at a co-located solar and BESS opportunity and you have seen a vendor proposal or a positive feasibility study, we are worth speaking to before you proceed. Not to tell you it is wrong — but to confirm whether it is complete.

Sources:

• Balkan Green Energy News: https://balkangreenenergynews.com/global-energy-storage-installations-surge-61-3-in-2025-with-ai-demand-set-to-drive-growth/
• Energy-Storage.News: https://www.energy-storage.news/whos-driving-the-300gwh-boom-in-demand-for-ai-data-centre-battery-storage/
• NESO Connections Reform: https://www.neso.energy/industry-information/connections-reform/about-connections-reform
• Knight Frank Connection Reform Update: https://www.knightfrank.co.uk/research/article/2025/12/connection-reform-update-a-new-pipeline-announced
• Sustainability Magazine / Montel: https://sustainabilitymag.com/news/infrastructure-keep-pace-renewables-supply
• S&P Global Energy Trends 2026: https://press.spglobal.com/2025-12-09-S-P-Global-Energy-Releases-Key-Clean-Energy-Trends-for-2026
• Morgan Lewis Energy Storage Report: https://www.morganlewis.com/pubs/2025/03/energy-storage-rides-a-wave-of-growth-but-uncertainty-looms-a-global-opportunity-and-regulatory-roadmap-for-2025