Car park canopies · checked 26 September 2026
Car Park Solar Canopies: Sizing, Yield and Consent
Car park solar canopies put generation on land you already own, at an orientation you choose, over vehicles that benefit from the shade. They are also more expensive per kilowatt than a roof array, and they take parking out of use while they are built. This page gives you the arithmetic to size one from your own bay count, the modelled yield for your city, the consent route in each UK nation, and the cost drivers in the order they actually matter — with the assumptions shown so you can substitute your own.
In short
- Size it from bays: about four modules per standard bay after allowances — roughly 1.7 kWp per space, so 100 bays is in the order of 170 kWp.
- Yield at a 10° pitch runs from about 946 kWh/kWp in Cardiff to 772 in Glasgow. Use your own city, not an average.
- Cost is led by the foundations, which come out of ground investigation — not by the panels.
- Consent differs by nation: Class OA prior approval in England, Class 9M in Scotland, a full application in Wales.
- It is a G99 connection, always, and it usually sets the programme.
What a car park canopy is, and when it beats a roof
A car park solar canopy is a free-standing steel structure carrying solar modules above parking bays. The vehicles keep using the space underneath; the generation happens above them. Because the frame is yours to orientate, you are not accepting whatever pitch and azimuth a roof happens to have — which is the one genuine performance advantage a canopy has over rooftop solar.
It is not, however, the cheaper option. A roof is a mounting structure you have already paid for. A canopy is a structure you have to buy, on foundations you have to dig, on a surface you then have to reinstate. So the case for a canopy is rarely "it generates more" — it is that the roof route is unavailable or insufficient:
- The roof is too small for the load you need to cover, but the car park is large.
- The roof cannot take the weight, or its remaining life is shorter than the array's.
- The building is leased, listed, or otherwise not yours to fix panels to.
- The roof is already covered and you need more capacity.
- You want covered parking or EV charging as part of the same capital project.
If your roof is sound, spacious and yours, start there — and come back to the canopy for the capacity the roof cannot carry. The head-to-head is set out on our commercial solar carport page, which covers the smaller single-row formats in more depth.
Sizing a canopy from your bay count
You can get to a usable system size without a survey, from geometry you already know. The assumptions are stated so you can change them:
- A standard UK parking bay is 2.4 m by 4.8 m, about 11.5 m².
- A current 430 W module measures roughly 1.13 m by 1.76 m, about 2 m².
- Six modules would fit over a bay on area alone. Allow for beams, gutter lines, edge setback and maintenance access and four modules per bay is a realistic planning figure.
- Four 430 W modules per bay is about 1.7 kWp per space.
Applying that, with PVGIS yields for a 10° pitch, gives the following planning-stage figures. These are arithmetic, not a design — a real layout loses bays to columns, aisles, turning circles and shading, and gains nothing back:
| Spaces covered | Indicative capacity | Modelled kWh/yr — Cardiff | Modelled kWh/yr — Manchester |
|---|---|---|---|
| 20 | ≈34 kWp | 32,200 | 27,400 |
| 50 | ≈86 kWp | 81,400 | 69,400 |
| 100 | ≈172 kWp | 162,700 | 138,800 |
| 200 | ≈344 kWp | 325,400 | 277,600 |
| 500 | ≈860 kWp | 813,600 | 694,000 |
What that table deliberately does not contain is a saving in pounds. A saving depends on the tariff you avoid and the share of output you consume on site rather than export, and both are specific to your load profile. Multiply the kWh by your own import rate and by a realistic self-consumption share, and treat any page that hands you a single payback figure with suspicion.
Yield by location at canopy pitch
| City | kWh per kWp per year (10° tilt) |
|---|---|
| Cardiff | 946 |
| Newport | 938 |
| Swansea | 921 |
| London | 920 |
| Birmingham | 875 |
| Manchester | 807 |
| Edinburgh | 805 |
| Aberdeen | 791 |
| Glasgow | 772 |
| Inverness | 734 |
Modelled in PVGIS for crystalline silicon at a 10° tilt with 14% system loss. A shallow pitch also sheds rain less effectively than a steep one, so soiling losses are marginally higher and the cleaning interval matters more than it does on a roof — covered on our solar canopy maintenance page.
Choosing the structural format
| Format | Covers | What it means in practice |
|---|---|---|
| Mono-pitch | Single row of bays, one column line | The simplest and cheapest per kWp. Columns sit on one side, the deck slopes away from them. Needs a column line that does not obstruct the aisle, which suits perimeter rows against a boundary. |
| Double / T-frame | Two facing rows from one central column line | One row of columns between two bay rows carries a deck either side. The most efficient use of columns per bay covered, and the format that usually wins on a large open car park laid out in paired rows. |
| Cantilever | Single row, columns at the rear only | Columns behind the bays, deck cantilevered forward, so nothing sits between vehicles. Best where the bay layout cannot be altered or where vehicle manoeuvring is tight. The cantilever moment makes the steel and the foundations heavier, so it costs more per kWp than a mono-pitch. |
| High-clearance | Any of the above, raised | Where refuse vehicles, ambulances, HGVs or high-roof vans need to pass. Extra height increases wind loading, which feeds back into the frame and the foundations — and in England the Class OA right caps overall height at 4 m, so a high-clearance canopy can push a scheme out of permitted development. |
The format follows the bay layout, not a preference. Where the aisle positions are fixed and columns cannot sit between vehicles, a cantilever is the only option and the extra steel is the price of that constraint. Where rows are paired across an aisle, a T-frame covers twice the bays per column line and is usually the most economical answer.
What actually drives the price
The modules are a commodity and the least interesting line in the quote. What moves the total:
- Foundations. Pads, piles or ground screws, decided by ground investigation. Car parks are often on made ground and dense with buried services, so this is both the largest variable and the one most often left as an assumption.
- Format and height. Cantilevers and high-clearance decks need heavier frames and heavier foundations. Wind uplift, not weight, governs a large light deck.
- Grid connection. A G99 application, and if the network needs reinforcement at the point of connection that is a different order of cost and time.
- Phasing. Keeping the car park open means working in sections and remobilising repeatedly. Closing it is cheaper per kWp and costs you the parking instead.
- Surface reinstatement. Every column base is a break-out and a make-good, and matching block paving or resin-bound surfacing is not free.
- EV integration. Cheaper now than later, because the ducting and switchgear are shared — see EV charging under a solar canopy.
The only published UK appraisal of a specific car park is DESNZ's, produced when it consulted on requiring canopies on new car parks. For an illustrative 80-space car park it used roughly £140,000 to install, about £28,000 a year of energy savings, about £22,000 a year of EV charging revenue and about £1,400 a year of maintenance — and, assuming a three-and-a-half-month closure, about £180,000 of foregone parking revenue. The disruption was the largest single figure in the case. That proposal was not taken forward, as the government confirmed on 21 May 2026, but the appraisal remains the most transparent public worked example. Cost bands by size are on our solar canopy cost page.
Consent and connection
England. Class OA of Part 14 has covered canopies above off-street non-domestic parking since December 2023. It requires prior approval, the authority has 56 days, glare is assessed in every case, and the limits include 4 m maximum height and 10 m from the curtilage of a dwellinghouse. Full conditions on our solar carport planning permission page.
Scotland. Class 9M, with its own limits and a straight exclusion for conservation areas — see the Scotland canopy guide.
Wales. No canopy right exists. The Welsh stand-alone non-domestic solar right is capped at 9 m² of panels, which no car park canopy approaches, so a Welsh scheme is a planning application from the outset — see solar canopies in Wales.
Grid. Always G99. G98's ceiling is 16 A per phase, about 3.68 kW single-phase and 11.04 kW three-phase, so no commercial canopy falls inside it. The application costs nothing to submit and is usually the critical path, which is the argument for submitting it the moment an indicative size exists. The full sequence is on our solar panel canopies installation page.
Rates. Qualifying on-site renewable generation plant is excepted from rating valuations until 31 March 2035, but the land and settings stay rateable and no guidance addresses a canopy's steel frame — see solar canopy business rates.
Six claims to be wary of
| Claim you will see | What the source says |
|---|---|
| "Car park canopies are permitted development under the GPDO if under 9 m and within 5 m of the building." | No such right exists. In England the canopy right is Class OA of Part 14, added by S.I. 2023/1279: it needs prior approval, the authority has 56 days, glare is always assessed, and the limits include 4 m maximum height and 10 m from the curtilage of a dwellinghouse. |
| "A canopy qualifies for 100% first-year tax relief." | Solar PV is special-rate plant and does not qualify for full expensing. The Annual Investment Allowance gives 100% relief on the first £1 million of qualifying expenditure in the period; expenditure above that attracts a 50% first-year allowance, with the balance in the special rate pool. |
| "Under 50 kWp you only need to notify the network operator." | G98 is capped at 16 A per phase — about 3.68 kW single-phase and 11.04 kW three-phase. Every car park canopy is a G99 application requiring approval before installation. |
| "The canopy is exempt from business rates." | The generation plant is excepted from rating valuations until 31 March 2035, but the land and settings stay rateable, and above about 50 kW the supports, brackets and settings are valued. No published guidance says how a canopy's steel frame is treated. |
| "Payback is 3 to 5 years." | Payback depends on the tariff you avoid, your self-consumption share, the foundation type and whether you lose parking revenue during construction. DESNZ's own illustrative 80-space appraisal put foregone parking at about £180,000 against a £140,000 installation — larger than the build cost. |
| "CE marked to BS EN 1090." | For products placed on the market in Great Britain the relevant marking is UKCA; CE marking applies in the EU and in Northern Ireland. BS EN 1090-2 is the execution standard for the steelwork itself, which is a separate matter from the marking. |
Car park solar canopies: questions
How big a solar canopy will my car park take?
Work from the bay count. A standard UK parking bay is 2.4 m by 4.8 m, about 11.5 m². A current 430 W module is roughly 1.13 m by 1.76 m, about 2 m². Geometrically six modules would fit over a bay, but once you allow for beams, gutters, edge setback and maintenance access, about four modules per bay is a realistic planning figure — roughly 1.7 kWp per space. So 100 bays is in the order of 170 kWp. That is a starting number for a feasibility conversation, not a design: the actual figure depends on the bay layout, the aisle positions, which rows can carry columns, and shading from buildings and trees.
How much will a car park solar canopy generate?
A canopy sits at a shallow pitch, typically around 10 degrees, because a steeper deck over parking bays needs more height and more steel. At that tilt the European Commission's PVGIS tool models roughly 946 kWh per kWp a year in Cardiff, 920 in London, 875 in Birmingham, 807 in Manchester and 772 in Glasgow. So a 170 kWp canopy over 100 bays models at about 161,000 kWh a year in Cardiff and about 137,000 kWh in Manchester. The 29% spread between the south of Wales and the Highlands is wide enough that a national average figure will misprice a scheme at both ends of the country.
Is a car park canopy cheaper than rooftop solar?
No — per kilowatt installed it is more expensive, because you are paying for a structure that a roof gives you free. What a canopy buys is capacity where a roof cannot provide it: a roof that is too small, too weak, leased, listed, already full, or due for replacement. It also lets you set orientation and tilt rather than accepting what the roof gives you, and it produces covered parking and a mounting platform for EV charging. The honest comparison is not cost per kWp but whether the roof route exists at all.
What determines the cost of a car park canopy?
In rough order of influence: the foundation type, which comes out of the ground investigation and is the largest single variable; the structural format, since a cantilever needs heavier steel and heavier foundations than a mono-pitch; the height, because wind uplift governs the design of a large, light, exposed deck; the grid connection, and whether the network needs reinforcement; the phasing, since keeping the car park open means remobilising plant repeatedly; and surface reinstatement, which is a visible cost on block paving or resin-bound surfacing. A price quoted before ground data exists is a provisional sum.
Do I need planning permission for a car park solar canopy?
In England a canopy over off-street parking at a non-domestic site can proceed under Class OA, but that is a prior approval route, not a free pass: the authority has 56 days to determine, glare is assessed in every case, and the limits include 4 m maximum height and 10 m separation from the curtilage of a dwellinghouse. Scotland has a separate right, Class 9M, which excludes conservation areas. Wales has no canopy right — its stand-alone non-domestic solar right is capped at 9 m² of panels, so a Welsh canopy is a full planning application.
How many EV chargers can go under the canopy?
Electrically, as many as the AC infrastructure and the connection agreement will carry; practically, the limit is usually the connection rather than the canopy. The value in doing it together is shared groundworks, ducting and switchgear — retrofitting those later is the expensive way round. The Workplace Charging Scheme contributes £500 per socket up to 40 sockets per applicant and runs to 31 March 2027, with the education strand at £2,000 per socket.
Sources
All checked on 26 September 2026.
- European Commission PVGIS — yields at 10° tilt, crystalline silicon, 14% system loss
- S.I. 2023/1279 (Class OA) and GPDO Schedule 2 Part 14
- Welsh Government — stand-alone non-domestic solar permitted development
- Energy Networks Association — G98 and G99 connection guides
- DESNZ — solar canopies on new car parks consultation
- S.I. 2022/405 — renewables plant rating exception
- HMRC — first-year allowances and Annual Investment Allowance
- Using the UKCA marking
This is general information, not engineering, planning or tax advice. This site is published by SEO Dons Ltd; we are not an installer.
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