What Is a Solar Carport?

A solar carport is a steel or aluminium canopy built over a parking area, with solar panels mounted on its roof, that generates electricity for the building beneath and can feed EV chargers directly below. It turns dead surface parking into a generating asset without using any roof space. The trade-off is cost: because you pay for the structure as well as the panels, a carport runs noticeably dearer per kWp than a rooftop array. They make the strongest case on retail parks, offices and multi-let estates that already hold large open car parks.

How a solar carport works

The panels on a carport behave exactly like rooftop panels. They convert daylight into direct current, an inverter turns that into the alternating current your building uses, and any unused power either runs EV chargers in the car park or exports to the grid. The difference is purely structural: instead of sitting on a roof, the array sits on a purpose-built frame raised typically 2.2 to 3 metres above the parking surface so vehicles fit underneath.

That elevation is the point. A carport gives you a clean, unshaded, optimally pitched surface that you control completely, with none of the roof complications, no membrane warranties to protect, no ageing roof structure to survey, no plant or rooflights to design around. The panels themselves are standard commercial modules, roughly 2m by 1.1m and around 400 to 590W each, at about 20 to 22% efficiency. They generate year-round, less in winter and more in summer, and cloud reduces output without stopping it.

The natural pairing is EV charging. A carport sits directly above the cars, so daytime generation can flow straight into AC chargers underneath with minimal cabling. That co-location is the reason carports are usually specified alongside an EV plan rather than as a standalone generator. Our commercial EV charging guide covers how to size charger counts against generation and grid capacity.

Class OA permitted development

Since changes to permitted development rules, ground-mounted and car-park solar canopies in England fall under a dedicated class, Class OA, which allows solar canopies over off-street car parks without a full planning application, subject to prior approval. (England rules; Wales, Scotland and Northern Ireland differ.)

The headline conditions are practical. The canopy is generally limited to a maximum height of 4 metres, it cannot be within the curtilage of a listed building or in certain protected areas without further consent, and the local authority must be given the chance to assess specific matters before work starts. The main one for car parks is glare: prior approval typically considers the effect of reflected light on highways, aircraft and neighbours, so a glare assessment is a normal part of the process. Design and external appearance can also be in scope.

Prior approval is faster and more certain than full planning, but it is not automatic, and it is not the same as needing nothing at all. You still submit, the council still has a defined window to respond, and conditions can attach. Treat Class OA as a streamlined route rather than a free pass, and confirm the current rules with your planning consultant before you design the array, because permitted development rights change and can be removed by local direction. Grid connection is usually the harder constraint anyway: anything above roughly 50kW needs a G99 connection agreement from your DNO, and that timeline often dictates the project, not planning.

What a solar carport costs

A solar carport costs more per kWp than an equivalent rooftop system, because you are buying a substantial steel structure on top of the panels and inverters. As a rule of thumb, rooftop commercial solar runs around £700 to £1,100 per kWp installed; a carport carries a structural premium on top of that, the size of which depends on ground conditions, foundation design, span, finish and whether integrated drainage or lighting is specified.

The economics still work where the structure earns its keep beyond generation. A canopy provides covered, shaded parking, protects vehicles and stock from hail and sun, and creates a clean, visible platform for EV charging that customers and tenants value. On a site with no usable roof, a weak or warranty-sensitive roof, or a planned roof replacement, a carport can be the cheaper route to solar overall once you account for the roof works you avoid. Run the numbers properly: our cost page sets out the per-kWp ranges and payback expectations, and the solar carports guide goes deeper on structure, foundations and the EV pairing.

On tax, solar qualifies as a special-rate asset and attracts 100% relief in year one through the Annual Investment Allowance (currently £1m), which reduces taxable profit rather than handing back the cost pound for pound; the cash benefit is roughly the relief multiplied by your tax rate. The structure and any charging equipment have their own treatment. Always take professional advice on your own position before relying on any allowance.

Which assets suit a solar carport

Solar carports fit best where three things line up: large surface parking, a daytime electrical load, and a reason the roof alone will not do. In practice that points to retail parks and out-of-town retail, where customer car parks are vast and footfall is daytime; offices and business parks, where staff parking sits empty of shade and the load runs in working hours; and multi-let industrial or mixed estates, where shared parking and a common-parts supply make the metering straightforward.

Owner-occupiers get the cleanest case, because they keep 100% of the savings and the EV revenue. Landlords face the familiar split incentive, the tenant pays the energy bill while the landlord funds the asset, which a carport does not magically solve; you resolve it the same way you would for rooftop, through a common-parts supply, a tenant PPA, a green lease or selling the roof or canopy as a service. We unpack those structures in the verticals for office investment property and retail parks and retail property pages.

Where a carport rarely makes sense is a small car park, a tight urban site with no parking, or a building with a large, sound, accessible roof and no roof-replacement on the horizon, in which case rooftop is simply cheaper for the same generation. Sizing should always come from your half-hourly consumption data and load profile, not from the area of the car park; the panels are sized to what you will actually self-consume, since self-consumption, typically 30 to 50% from solar alone and 60 to 80% with a battery, is the single biggest driver of return.

If you have surface parking standing idle and an EV plan taking shape, a solar carport is worth costing against a rooftop array rather than assuming one or the other. The right answer depends on your roof, your load and your grid connection, and the only way to know is to model your site specifically. Request a quote and we will assess your parking, your half-hourly load and your DNO position, then set out whether a carport, a rooftop system or a combination gives you the better return.