Powering Change
Installing since 2010 · 0118 951 4490 · info@spiritenergy.co.uk
Your saving depends on system size and how much of the generation your site uses as it is produced. Philip Dennis Foodservice is projected to save more than £85,000 a year from its 695 kWp system, and more than £2.4 million over 20 years. Warehouses save most when daytime loads such as lighting, ventilation, refrigeration and forklift charging use the solar power directly, because every unit used on site is a unit you no longer buy from the grid.
| Spirit Energy warehouse project | System | Annual saving | Payback | IRR |
|---|---|---|---|---|
| Philip Dennis Foodservice, Oxfordshire | 695 kWp | £85,000+ (projected) | Under 5 years | 23%+ |
| Cathedral Hill Industrial Estate, Guildford | 500 kWp + 351 kWh battery | £47,943 (estimated) | 5 years | 23% |
| Spirit House, Reading | 54.61 kWp | £6,500 (year one) | 4 to 5 years | 24% |
Allow roughly 5 to 6 square metres of usable roof for every kilowatt-peak (kWp, the maximum output of a solar system), so a 100 kWp system needs about 500 to 600 square metres. Most warehouse roofs have far more than that: Philip Dennis Foodservice fitted 1,636 panels across its warehouse and cold store roofs. Rooflights, plant, gutters and fire access routes all reduce the usable area, so Spirit Energy measures your roof on site rather than estimating from a plan.
Many steel-framed warehouses can take the extra weight of a solar array, but only a structural check confirms it for your building. Rail-mounted panels on a profiled metal roof add a modest load spread across the roof. Ballasted systems on flat roofs weigh more, because they are held down by heavy blocks rather than fixed to the roof.
Often yes, but not by fixing straight through the old sheets. Asbestos cement roofs are common on warehouses built before 2000, and drilling into them can release fibres. The usual routes are to over-clad the roof with new metal sheeting and mount the panels on that, or to replace the roof first. Both options also stop leaks and improve insulation, and the roof work and solar installation can run as one project. Philip Dennis Foodservice had its roof replaced at the same time as Spirit Energy installed its 695 kWp system, with both contractors on site together. If you have an asbestos register, have it ready for the site survey.
Yes, with your landlord's written consent, which almost every commercial lease requires for roof alterations. Three arrangements are common: you install and own the system under a licence for alterations; your landlord installs it and sells you the electricity; or a funder installs and owns it under a Power Purchase Agreement. Check the years left on your lease against the payback period, and agree in writing who owns, maintains and insures the panels if you leave. More landlords are now installing solar themselves. At Cathedral Hill Industrial Estate in Guildford, Savills Investment Management had Spirit Energy fit solar panels and batteries across 13 refurbished units, which are now let to tenants including Halfords and Screwfix.
Tell your insurer before installation. Solar changes the risk on your roof, and most insurers will want to see the design. UK insurers assess commercial rooftop solar against RC62, the fire safety code of practice published by the Fire Protection Association with MCS and Solar Energy UK. Fires involving solar systems are rare in the UK, and RC62 sets out what keeps that risk low: correct cable routing, isolation, clear roof access routes and regular inspection. Commercial solar servicing keeps your system inspected and documented for your insurer.
No, not in England. Rooftop solar panels, battery storage used with them and EV charge points are exempt from business rates from 1 April 2022 until 31 March 2035, under the Valuation for Rating (Plant and Machinery) (England) (Amendment) Regulations 2022. Your system cuts your energy bills without increasing your business rates. Wales and Scotland set their own business rates rules, so check locally if your warehouse is outside England.
If you buy the system, you can usually deduct the full cost from your taxable profits in the year of purchase. The Annual Investment Allowance (AIA) covers up to £1 million of qualifying spend a year. Solar panels are special rate assets, so a company spending beyond its AIA can claim a 50% first-year allowance on the excess, with the rest written down at 6% a year. These reliefs apply when you buy through capex or hire purchase, not under a PPA, where you don't own the system. Philip Dennis Foodservice took the PPA route and installed with no deposit. Confirm your position with your accountant.
Yes, it can close much of the gap. On 18 June 2026 the government confirmed its intention that privately rented non-domestic buildings over 1,000 square metres in England and Wales must reach EPC B from 2031, where improvements are cost-effective. Many warehouses are well over that size. On-site solar counts towards your EPC rating and works alongside LED lighting and heating upgrades. The rule is a policy intention, not yet law, and buildings under 1,000 square metres stay at the current minimum of EPC E.
Almost every warehouse system needs approval from your local Distribution Network Operator (DNO) under the G99 process before connection. Approval can take 8 to 24 weeks. The DNO checks whether the local network can accept power exported from your site. Where capacity is tight, your system can still go ahead with an export limit, which caps what flows back to the grid while you use the rest on site. When DNO constraints hit Spirit Energy's own Reading headquarters, the design went from 157 panels to 127, and the system still pays back in 4 to 5 years. Spirit Energy handles the DNO application and submits it early so approval doesn't hold up installation.
Yes, and these loads often make warehouse solar pay back faster. Electric forklifts charge during the working day, chillers and cold stores work hardest on the sunniest days, and electric vans can top up between runs, so each uses solar power as it is generated. At Philip Dennis Foodservice the cold store uses most of the site's electricity, so 328 kWp of the 695 kWp system sits on the cold store roof. Commercial battery storage carries daytime generation into evening shifts, as the 27 kWh fitted to each Cathedral Hill unit does, and commercial EV charging can be designed in alongside the solar.
A Spirit Energy survey checks your roof structure, your electrical supply and 12 months of your electricity bills. You get a site-specific design and financial model showing generation, savings, payback and how each funding route compares: capex, hire purchase or a PPA. Spirit Energy has installed solar since 2010, with more than 6,000 installations, and is MCS certified. To book your survey, request a quote or call
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