How much does solar cost for a shopping centre?

Solar for a shopping centre is priced per kilowatt of installed capacity, and the rate usually falls as the array gets bigger, so ask each installer for an itemised price per kWp and compare quotes like for like. For small installations up to 50 kW only, DESNZ cost data for MCS installations in 2025/26 gives a GB mean of £1,808 per kW for 0-4 kW systems and £1,622 per kW for 4-10 kW systems. These are small-scale means, not commercial prices: a 250 kW to 2 MW commercial scheme is priced per quote. A solar carport over the car park costs more per kW than rooftop because of the steel structure beneath the panels, but it unlocks a surface that would otherwise generate nothing and it can pair with EV charging. Cost is one part of the case: the guide to solar panels for shopping centres covers roofs, common-area loads and how a scheme is structured. To turn a quote into a business case, the method for working out payback and ROI is set out in a separate guide. How big the array should be is a separate question: see common-area versus whole-roof solar.

The right number for your scheme is driven by load, not by roof area. A shopping centre's value lives in its landlord-controlled common-area demand: mall and concourse lighting, escalators and lifts, atrium and food-court ventilation, signage, water features, and car-park lighting and EV charging. That demand runs through every trading hour, which is exactly when an array generates, so a well-sized retail array self-consumes a high share of what it produces. The usual approach is to size from twelve months of half-hourly common-area meter data, aiming at daytime demand rather than simply filling the roof. Over-sizing past your self-consumption ceiling pushes more generation onto export, which earns less than the grid power you avoid.

What you actually save, and how payback is measured

The saving on a retail scheme comes mostly from avoided grid purchase, because every self-consumed kWh displaces power bought from the supplier. Surplus generation at quiet times, early mornings and out-of-season weekends, is exported and paid under the Smart Export Guarantee, where suppliers set the rates and terms, though export is a smaller part of the case for an all-day retail load than it is for a seasonal site.

Simple payback (net cost divided by annual saving) is the headline most owners want. It is a blunt measure though. Internal rate of return and net present value over the life of the array tell a fuller story, and for a landlord weighing solar against other capital projects they matter more. A proper appraisal models all three, plus the levelised cost of energy, so the array can be compared against the current and forecast grid tariff on a like-for-like basis. Model it from twelve months of half-hourly meter data.

How retail schemes get funded

There are three routes, and the right one depends on whether you want the asset on your balance sheet. Capital purchase plus tax relief is the simplest: you buy the system and claim capital allowances against it. Solar is a special-rate plant-and-machinery asset, so the Annual Investment Allowance (£1m) usually gives 100 percent relief in year one for a business under the limit, at the company's own corporation tax rate. Spend above the £1m limit can claim the 50 percent First-Year Allowance.

A power purchase agreement can remove the capital outlay. A funder owns the array on your roof and you buy the power it produces at a rate set in the contract, which should be compared with your grid tariff. Asset finance sits between the two: the system goes on your balance sheet and the cost is spread over the finance term, so compare the repayments with the expected saving. For a leased or multi-let scheme, the funding question runs into the landlord-and-tenant structure, who pays for the array and who banks the saving, which is normally resolved through the service charge or a green-lease rent share.

The costs people forget to budget for

The installed price covers panels, mounting, inverters, cabling and commissioning, but a few items sit outside it. The grid connection is the first: any array above 16 A (3.68 kW) per phase needs a G99 application to the local network operator, and on a busy network the DNO sets the programme and may charge for reinforcement. Whether the site already has a high-voltage connection should be confirmed early because the G99 process is often the longest item in the programme. A structural survey should be done before loading panels onto a mall or service-deck roof, and an older roof at or near the end of its life may need replacing first, in which case ask whether a combined re-roof and PV project makes sense. Re-roofing is standard-rated for VAT, and a commercial scheme pays the standard 20 percent, recoverable by a VAT-registered business.

Other variables that move the price include the roof type (ballasted systems on flat membrane roofs differ in cost from rail-fixed systems on profiled metal), access and scaffolding on a multi-storey structure, the split landlord and tenant metering that has to be configured so the array feeds the right supply, and any conservation or planning constraint that forces a discreet design. Asbestos cement on older outbuildings cannot be retrofitted and needs replacement before any array goes on. A good feasibility stage flags all of these, so the budget quoted is the budget paid.

Timeline and cash flow

From first conversation to a generating array, the grid connection usually sets the pace, so the G99 application should go in early. The physical install is short by comparison, and rooftop work can be phased in zones and kept off the shop floor. The only outage is the final grid tie-in, which should be booked for a quiet period. From the day it energises, the array starts cutting the bill.