Commercial solar for retail

Retail is one of the better-matched sectors for rooftop solar. The reason is timing: shops draw their heaviest load during the day — refrigeration and chillers, lighting, air handling, EPOS and card terminals, and often electric heating — which is exactly when panels generate. That overlap means a large share of the electricity you produce is used on site, avoiding the full delivered price you pay your supplier rather than being exported at a lower rate.

Three things drive the outcome for any given store: how much roof (or ground) you have, how much of your own generation you can use, and the price you currently pay per unit. Non-domestic electricity averaged roughly 25–27p per kWh for UK businesses in early 2026¹, so every unit you self-generate and self-consume is worth close to that. This page walks through each factor with typical 2026 figures, then points you to the matching size and finance pages.

See the commercial solar hub for the full sector index, or the retail sector page if you have arrived here from elsewhere.

As a planning rule of thumb, allow about 7 m² of usable roof per kWp of panels. A single mid-size store or retail-park unit with 300–700 m² of clear, reasonably unshaded roof will typically support a 40–100 kWp system; a smaller high-street shop with limited or shaded roof might only take 10–20 kWp. Larger supermarkets and big-box units can go well beyond 100 kWp.

Retail roofs vary more than warehouses: parapets, plant, rooflights, signage and shared or leasehold roofs all reduce the usable area, and older buildings may need a structural check before panels go on. Where roof space is tight, a canopy over customer car parking is a common alternative that also creates shade and supports EV charging.

Compare sizes directly on the cost pages: 10 kW, 20 kW, 50 kW, 100 kW.

Self-consumption is the single biggest lever on retail solar economics. A self-consumed unit is worth your full delivered tariff (around 25–27p/kWh in 2026¹); an exported unit earns only the Smart Export Guarantee rate you have agreed with a supplier, which sits well below that⁴. The more you use on site, the better the return.

Commercial self-consumption generally runs 60–85% depending on sector. Retail sits toward the upper end — commonly 70–85% — because trading hours are long and the base load (refrigeration, cold storage, HVAC, lighting) is steady through the day. Stores with 24/7 refrigeration or extended opening hours can be higher still; a shop that closes early or has a small daytime load will be lower.

If your load is genuinely evening- or weekend-weighted, or you want to lift self-consumption above what daytime use allows, a battery can shift midday generation into later trading hours — covered in next steps.

Installed commercial solar prices in 2026 fall as systems get larger, thanks to economies of scale. Independent 2026 price guides put sub-100 kW systems at roughly £900–£1,200 per kWp and 100–500 kW systems at roughly £750–£950 per kWp installed, before VAT⁵. Very large ground-mount or big-box roofs can push below that. These figures exclude extras that can be material on a retail roof: DNO/G99 grid application on larger systems, structural reinforcement, scaffolding and any switchgear upgrade.

The table below is a worked illustration for a mid-tariff retail site at 26p/kWh, 75% self-consumption and a 7p/kWh export rate. It is an estimate for a typical site; your figures depend on your load, roof and tariff, and it excludes tariff inflation and panel degradation.

Commercial payback in 2026 commonly lands in the 5–8 year range against a 25–30 year design life; a high-self-use retail site can be at the faster end. Before deciding, weigh outright purchase against a power purchase agreement on our buy vs PPA page.

Two tax points are widely misunderstood, so it is worth being precise.

VAT. The 0% VAT rate on solar applies to domestic and residential installations only. A commercial solar installation is charged the standard 20% VAT³. A VAT-registered business can normally reclaim that input VAT in the usual way, so it is typically a cash-flow item rather than a permanent cost — confirm your position with your accountant.

Capital allowances. Solar PV is treated as special-rate plant and machinery. That matters because 100% full expensing applies to main-rate assets only, so it does not cover solar. Special-rate plant instead qualifies for the 50% first-year allowance, letting a company deduct 50% of the cost in year one, with the balance entering the special-rate pool at 6% writing-down allowance thereafter². The Annual Investment Allowance may also be available. The interaction of these reliefs depends on your total plant spend and profits — your accountant should confirm what applies before you rely on any figure.

Different premises have different load shapes, which changes how well solar fits. Retail is favourable because generation and demand overlap through the trading day.

• Warehouse — very large, unshaded roof and high daytime self-use; often the strongest fit by area. See warehouse.
• Factory — very high daytime demand can absorb a large system with excellent self-consumption. See factory.
• Farm — ground-mount is an option alongside roofs, adding income diversification and typically high self-use. See farm.
• School — summer holidays cut self-use exactly when generation peaks, so export arrangements or a battery matter more. See school.
• Retail — daytime demand matches generation well, giving high self-consumption without much extra kit.
• Hotel — evening- and weekend-weighted load means a battery often helps shift solar into peak use. See hotel.

Most retail sites get strong returns from solar alone because daytime self-consumption is already high. A battery is worth modelling where you have meaningful evening trading, want to raise self-consumption past what daytime use allows, or want resilience against outages — but it adds cost and lengthens payback, so it should earn its place on your specific load profile rather than being assumed.

Before committing, a credible quote should be based on a site survey, your actual half-hourly consumption data, a structural check on the roof, and a clear DNO/grid-connection position. That is what separates a real number from a rough estimate.

Read how to choose an installer for what to check, then when you are ready, request a quote. PlutoHome matches you with a single MCS-certified⁶ commercial installer for a site-specific proposal — one introduction, not five sales calls.