Distribution Centres: Solar panels for cold storage

Why a distribution centre is one of the best solar roofs in UK logistics

When people think about solar panels for cold storage they often picture a single chilled warehouse, but in practice the cold chain runs through the distribution centre too. A modern DC carries ambient and chilled bays under one roof, with materials handling equipment charging through the day and refrigeration and lighting drawing power around the clock. That mix of loads is exactly what makes a distribution centre such a strong site for rooftop solar. The electricity your panels generate is used on site against a genuine daytime baseload rather than exported at a lower price, and self-consumption is the single biggest driver of solar payback. With a typical simple payback of around 5.5 years, a well-sized DC array is one of the more dependable capital investments available to a logistics operator, and the chilled element of the building only strengthens the case because refrigeration runs whether the order book is busy or quiet.

The financial pressure is real and getting worse. TNUoS and BSUoS network charges have risen by 40 to 80 percent since 2022 and land directly on the logistics profit and loss, while customer Scope 2 and Scope 3 mandates from the likes of the Amazon Climate Pledge, Tesco net zero and Unilever CTAP now flow straight through to 3PL operators and tenants. A distribution centre sits at the heart of that supply chain, so on-site generation is both a hedge against rising network costs and auditable evidence of carbon reduction that increasingly appears in customer audit packs as a contract-winning factor. The buildings themselves are designed almost perfectly for PV: massive clear-span steel-portal roofs, free of obstructions and structurally sound. For a building with that much underused roof estate, every quarter without solar is money left on the table, and the insurance market has hardened around large-roof PV precisely because poor installs elsewhere have made underwriters cautious, which is why getting the engineering right matters so much.

What a typical install looks like and how we size it

For a distribution centre we usually design a system in the 500 to 3,000 kW range, which is roughly 920 to 5,500 panels across about 3,000 to 18,000 square metres of clear-span steel-portal roof. A system that size generates in the region of 460,000 to 2.75 million kWh a year and saves somewhere between 106 and 633 tonnes of CO2 annually. We never simply fill the roof. Sizing on a warehouse is unusual because roof area is rarely the binding constraint; the real limits are daytime baseload and DNO capacity. We always pull your half-hourly meter data first, because many distribution centres have a surprisingly low daytime baseload between order peaks, and an array sized to an optimistic maximum would export too much at a poor price.

The MHE charging fleet is the key to a good DC design. Forklift and reach-truck charging provides excellent daytime self-consumption, and where that charging coincides with the solar peak we can size the system more confidently. The chilled and frozen bays add a steady round-the-clock baseload underneath the daytime peaks, which lifts self-consumption further still. For pure daytime operations of roughly 06:00 to 18:00, a battery is increasingly economic at scale and lets midday generation cover the early evening tail. M1, M6 and A1 corridor sites tend to be the highest priority because the buildings are large, modern and structurally suited to PV, and because the operators on those corridors feel the customer sustainability pressure most acutely. We model the array against your real load curve, not a generic warehouse profile, and present the sizing logic openly so you can see why the system is the size it is.

Costs, payback and tax relief

A distribution centre project typically lands between £350,000 and £2.4m depending on system size and roof area, at roughly £700 to £900 per kW, with larger schemes often achieving £600 per kW or below at scale. Simple payback sits near 5.5 years, after which the electricity is effectively free for the rest of the system's long life. The biggest financial lever is tax. Solar PV qualifies as plant and machinery, so the 100% Annual Investment Allowance lets most warehouse installs be fully expensed in year one up to the £1m cap, with a 50% First Year Allowance on qualifying spend above that, subject to current legislation. For a limited company that relief is worth up to a quarter of the project value back as tax saved in the first year, which materially shortens the effective payback.

The Smart Export Guarantee pays for any surplus you export at 4 to 15p per kWh as of 2026, though on a busy DC with chilled load most generation is consumed on site and export is modest. Where the building is leased, the tax shield from capital allowances can become a negotiation point with the operator or landlord, and a PPA can deliver the system with no capex at all. Our cost guide sets out worked numbers by system size so you can see how the figures move with scale.

Funding routes in detail

There are several ways to fund a distribution centre system, and the right one depends on whether you own or lease the building. Capital allowances are the headline relief: most DC installs are fully expensed in year one under the Annual Investment Allowance, with the 50% First Year Allowance covering qualifying spend above the cap, and combined with PPA finance the tax shield can become a negotiation point with tenants or operators. If your building sits within a designated UK Freeport or Investment Zone, Enhanced Capital Allowances can deliver effective 100% first-year tax relief on qualifying new plant and machinery, so it is always worth checking the zone status of the site.

For tenants, the Green Lease Clause and tenant capital recovery route is increasingly standard. It is not a grant, but it unlocks your ability to install solar on a leased building, and we provide a lease addendum aligned with the BBP Green Lease Toolkit, which most institutional landlords such as Prologis, Tritax, Blackstone and GLP will accept. Consent typically takes four to eight weeks for an institutional landlord and one to four weeks for owner-occupied or family-owned property. The Smart Export Guarantee contributes for any exported surplus. Where the distribution centre handles food and falls within the right SIC code, the Industrial Energy Transformation Fund may also be worth checking, though most pure logistics 3PL operations do not qualify. We work through every route that applies to your site as part of the feasibility, so nothing is left on the table.

Compliance and sector considerations

Sprinkler clearances are mandatory on a distribution centre, and we design to LPC sprinkler clearance standards (1m to the deflector, 0.6m at high-bay) so the PV layout is built around your sprinkler heads, not the other way around. Insurer engagement is essential; the large-roof PV risk profile is well defined now, and we include insurer pre-design review as standard so we get sign-off before fabricating anything. The major insurers, including Allianz, AIG and Zurich, all have specific PV criteria, and meeting them up front protects your cover. Emergency access routes are maintained per the fire risk assessment, and where fire detection integration is involved the work meets BS 5839-1 and SPF1981 v3 fire safety design.

Most warehouse PV falls under permitted development through Class A Part 14 of the GPDO 2015, and listed building or conservation constraints are rare for logistics buildings. On the grid side, anything above 17 kW per phase needs a G99 application, and large installs above 1 MW often need a bespoke DNO study and contestable connection works; many warehouses retain generous capacity from past industrial use, but we always confirm rather than assume. Wind loading is designed to BS EN 1991-1-4 for the specific terrain category, and where chilled bays form part of the building the refrigeration plant remains subject to the F-gas Regulations. We also handle the tenant capital improvements position in the lease where the building is leased, so the legal and technical strands move together.

How we approach this kind of project

Our approach is built to remove the things that usually stall warehouse solar. We start by pulling your half-hourly meter data so the system is sized for genuine self-consumption rather than an optimistic roof fill. We carry out a roof and structural check, including a wind-load assessment to BS EN 1991-1-4, before we commit to a layout, and we confirm the roof build-up so the fixings suit the deck. We submit the G99 grid application early so the DNO clock starts while the survey and design proceed in parallel, which is often the single biggest factor in hitting a target energisation date.

We engage your insurer for pre-design review and confirm sprinkler clearances before fabrication, so there are no surprises late in the build. You receive a fixed-price proposal rather than an estimate that drifts, and the workmanship is covered by an insurance-backed warranty. Crucially, we do not take the building offline: roof installation happens above your operations while MHE, picking and despatch continue normally, and the only outage required is the final grid synchronisation of four to eight hours, which we schedule for a weekend or planned shutdown. Where clients have needed us to install through peak season we have delivered that with no operational impact. We are MCS, NICEIC, RECC and TrustMark certified and work to ISO 9001, 14001 and 45001, so the quality and safety systems sit behind every project.

An illustrative example

As an illustrative composite based on typical UK distribution centre projects: a national 3PL operating a large M1-corridor distribution centre serving major retail chains, with an existing electricity spend in the region of £620,000 a year and a tenant on a long FRI lease with green-lease provisions, installed around 1.18 MW of roughly 2,170 panels generating about 1,090,000 kWh a year. The scheme was PPA-funded with zero capex, self-consumption settled near 84%, the annual saving sat around £245,000 for a payback close to 5.1 years, and the customer audit pack gained auditable Scope 2 reduction, with further sites then moving into scoping. The figures are illustrative and depend on your building, tariff, roof and funding route.

If your estate mixes ambient and chilled handling, our pages on solar for cold chain warehouses and fulfilment centre solar may also apply. When you are ready, see the cost guide and funding routes, then request a free feasibility from your meter data, or read the cold storage solar FAQs first.