Solar panels for warehouses and logistics sites

Why warehouse roofs suit solar, and when they do not

Distribution sheds, cross-dock facilities and storage buildings tend to have large, uninterrupted roofs with no neighbouring buildings tall enough to cast shade. A single-storey portal frame building of a few thousand square metres can physically hold an array far bigger than most offices or shops could ever fit.

The question a survey really answers is how much of that roof is worth covering. A warehouse's electricity demand varies enormously with what happens inside it:

Sizing an array to the building rather than to the demand is a common mistake. Electricity you use on site displaces your own unit rate, while exported electricity earns only an export tariff, which is usually far lower. The survey uses your half-hourly data to find the size where self-consumption stays high. That trade-off between array size and self-consumption is the main thing the survey's savings model tests.

Many logistics operators are also electrifying. Electric forklifts and reach trucks already draw a lot of power, and electric vans and HGVs add more. If the fleet is going electric over the next few years, it can make sense to size the array for the demand you will have rather than the demand you have today, and to look at EV charging for business at the same time.

The building issues a warehouse survey checks

Roof sheets and rooflights

Most modern sheds are clad in profiled steel or composite insulated panels, which suit rail-mounted or clamp-mounted systems well. Our page on metal roofs covers fixing methods in more detail. Older sheds, particularly those built before 2000, may have fibre cement sheets that contain asbestos, and these need a different approach covered on the asbestos roofs page.

Rooflights are a particular feature of warehouses. Translucent sheets bring daylight into the racking aisles, but panels cannot go over them without losing that light, and they are fragile, so they are a fall hazard during installation. The surveyor maps them, because they often break the roof into strips and reduce the usable area more than people expect.

The surveyor also looks at sheet condition: cut edge corrosion along the eaves, failed fixings, coating breakdown and any history of leaks. Putting a 25 year asset on a roof with ten years of life left rarely makes financial sense.

Frame capacity

Portal frame warehouses are usually designed efficiently, with limited spare capacity beyond the snow and wind loads the building was designed for. Framed panels on rails typically add around 10 to 15 kg per square metre, which many sheds can take, but purlin size, spacing and condition all matter. A structural survey confirms the real figure before a design is finalised.

Fire strategy and insurance

Warehouses hold a lot of stock under one roof, so insurers take a close interest. The RC62 recommendations published by RISCAuthority and the Fire Protection Association are widely referenced. Typical points include keeping panels clear of compartment walls, avoiding routing DC cables through high-risk areas, and making sure the fire service can isolate the system. If the building has combustible-cored insulated panels, the insurer may have specific conditions. Our fire safety and insurance guide explains what to ask.

Grid connection and cable runs

Big sheds often have the main LV switchboard at one end and the best roof area at the other, so cable routes can be long. Larger arrays need G99 approval from the DNO, and in areas with constrained networks an export limitation scheme under G100 can let a bigger array connect where full export would not be allowed.

Working around operations

Yard traffic, HGV movements and loading bays all affect how the installer gets materials and access equipment onto the roof. The survey notes where cranes or mobile elevating work platforms can safely stand and which areas need to stay clear.

Finance and ownership questions for warehouses

Many logistics buildings are leased rather than owned, often on full repairing and insuring leases. That changes who can install, who benefits and how long the arrangement needs to last.

• Owner-occupiers can usually buy the system outright. In our illustrative 100 kWp example (£900 per kWp, 80% used on site at 24p per kWh), simple payback is roughly 5 years before tax relief. Solar panels are special rate expenditure for capital allowances, so check the treatment with your accountant.
• Tenants need landlord consent, and the remaining lease term matters. If the lease ends before the system has paid back, the tenant may be funding an asset the landlord keeps.
• Third-party logistics operators often run a site under a customer contract shorter than the panel life. A power purchase agreement, where a funder owns the system and sells you the electricity, can avoid tying up capital against a contract that might not be renewed.
• Landlords can install and sell power to the occupier, or lease the roof to a third party. Our commercial landlords page covers those models.

What to have ready for a warehouse survey

• At least 12 months of half-hourly consumption data, or your supplier's details so it can be requested
• Shift patterns, including weekends and peak trading periods
• Site plan and roof drawings, if you have them, plus any structural information from when the building was built
• Your asbestos register or management survey, for older buildings
• Lease, or at least the remaining term and the landlord's contact details
• Insurer contact and any conditions already on the policy
• Plans for fleet electrification, more automation or extra cold storage

With that information the survey can model a realistic array and payback for your building. When you are ready, request a free survey.