Are Solar Car Parks (Carports) Worth It?

It is a fair question, and it deserves a straight answer rather than a sales pitch. Solar carports cost more per kilowatt than rooftop solar, and they pay back more slowly on the panels alone. So are they worth it? For the right site, yes, clearly, but the reasoning is more interesting than a simple payback figure, because a solar carport does several jobs a roof never can. This guide weighs the case honestly: where carports win, where they do not, and how to tell which side of that line your car park falls on.

What a solar carport actually is

First, the thing itself, because the cost only makes sense once you understand it. A solar carport is a ground-mounted steel canopy built over the bays of a commercial or public car park. It is not a roof array. It is a structure, columns, beams, purlins and a canopy frame, engineered to stand over live parking and carry wind and snow load, with solar panels mounted on top. That structural distinction drives everything that follows: the cost, the longer payback, and the extra value.

The honest case against: it costs more and pays back slower

Let us put the downside first. Solar carports cost around £1,200 to £3,000 per kWp installed, against roughly £600 to £1,000 for rooftop. Payback on the panels alone is typically 8 to 10 years, against 5 to 7 for a roof.

The reason is the steel. On a rooftop install the surface already exists, so you pay for panels and little else structurally. A carport has to build the surface first, and that steel structure is roughly 45% of the total project cost. There is no getting around it: if you have an empty, suitable, structurally sound roof going spare, fill the roof first, because it will pay back faster.

That is the genuinely fair objection, and any installer worth dealing with will say it plainly.

The case for: a carport does jobs a roof cannot

Here is where the calculation turns. The panel-only payback ignores almost everything that makes a carport worth building. There are four arguments in its favour.

1. Dual land use: your car park earns nothing today

A surface car park is dead space financially. It earns nothing per square metre, yet it is often the single largest flat, unshaded, south-facing surface a commercial site owns. A solar carport turns that dead tarmac into a generating asset without taking a single bay out of use, the cars park underneath the panels. For most sites, the roof is already full or already committed, and the car park is the only solar surface left. Dual land use is the whole point: you keep the parking and gain the generation.

2. EV charging you have to install anyway

This is the argument that tips most decisions. Retail, employer, healthcare and leisure car parks are under growing pressure to provide EV charging, for customers, staff and fleets, and that infrastructure has to be funded regardless of whether you build a carport. A solar carport carries the structure, the cable routes and a behind-the-meter solar supply for those chargepoints. Deliver the two together and you dig the car park once, not twice, and daytime solar feeds the chargers at your generation cost rather than full grid retail. If you are going to install charging anyway, building it under a solar canopy is the cheapest way to do both.

3. Funding that closes the gap

Several routes stack on a carport and materially shorten the real payback. The Workplace Charging Scheme can part-fund the EV sockets through an OZEV-authorised installer (check gov.uk for the current contribution rate, per-socket cap and closing date). The PV plant qualifies for the 100% Annual Investment Allowance, worth up to a 25% effective tax saving in year one for a limited company on the plant element. Surplus generation earns income under the Smart Export Guarantee at typically 4 to 15p per kWh in 2026. Public-sector sites may access the Public Sector Decarbonisation Scheme via Salix. Counted together, these change the answer.

4. A visible decarbonisation statement

A rooftop array is invisible: no customer, member of staff or investor ever sees it. A solar carport is the opposite. It is a large, customer-facing structure that visibly signals a decarbonisation commitment, with sheltered EV charging beneath it. For retailers, attractions, universities and employers that need to show, not just report, their sustainability story, that visibility has real commercial value in footfall, recruitment and brand.

Planning is easier than most people assume

A common reason buyers hesitate is the belief that a canopy over a car park needs full planning permission. In England, since December 2023, usually it does not. Class OA of the General Permitted Development Order allows solar canopies on non-domestic, off-street car parks under a lighter-touch prior-approval route: a 56-day determination by the local planning authority on siting, design, glare and drainage, rather than full planning.

There are limits. The canopy must be no higher than 4m and not within 10m of a residential boundary, and the right excludes listed buildings, scheduled monuments and conservation areas, which still need full planning. Class OA does not currently extend to Wales or Northern Ireland. Two technical conditions catch people out: glare onto neighbouring premises, the highway or any flight path is the most common prior-approval condition, manageable with a glare and glint study, and a new canopy over open tarmac is a new impermeable surface, so a SuDS drainage strategy is required. Both are routine for a competent installer, but they are real and should be designed in from the start.

So, is it worth it? It depends on the site

The honest answer is that worth depends on the site, and a few questions sort the strong candidates from the weak ones.

A solar carport is worth it when:

• The roof is already full or unsuitable, and the car park is the only solar surface left.
• The site has strong daytime electricity demand, so most generation is self-consumed at full retail rate rather than exported cheaply. A supermarket, a 24/7 hospital or a fully occupied weekday office all qualify.
• EV charging is needed anyway, so the carport funds infrastructure you were going to build.
• The car park is large. Because the steel cost is broadly fixed per bay, the case improves sharply with scale, a 50-bay scheme is far better value than a 10-bay one.
• A visible sustainability statement carries commercial weight for the brand.

A solar carport is harder to justify when there is a big empty roof going spare, when the car park is small, or when daytime on-site demand is low and most generation would be exported.

The right comparison

The single mistake to avoid is judging a carport on its panel-only payback against a rooftop array. That comparison misses dual land use, the EV-charging synergy, the funding stack and the brand value, all of which a roof lacks. The right figure is the blended return: solar savings, charging value or avoided grid cost, the grant, and the tax relief, modelled together. On that basis, for a large car park with daytime load and an EV-charging need, a solar carport is comfortably worth it.

Find out for your own car park

Whether a carport is worth it for you turns on your bay count, your load profile and your EV plans. Run a first estimate in our savings calculator, read the full cost and payback breakdown, check the grants and funding you can stack, or see how the case looks for workplace and office car parks specifically. When you want a straight answer for your own site, request a free feasibility.