Search for what a commercial solar canopy costs and you will be handed a per-kilowatt band inside about four seconds. Search a second page and you will get a different one. Neither will tell you where the number came from, and that is not an accident — it reflects a genuine absence of published UK data.
This piece explains why, what the one real figure is, and how to compare quotations without a benchmark. The sizing and yield arithmetic it refers to sits on our solar panel canopy page.
Why the data does not exist
Three reasons, and none of them is secrecy.
Canopies are not a product, they are a project. Two canopies of identical capacity on identical bay counts can differ by a third in price because one sits on competent ground and the other on made ground full of buried services. The foundation type — pads, piles or ground screws — comes out of an intrusive ground investigation, and it is the largest single variable in the total. A published price per kWp necessarily assumes ground conditions it cannot know.
The volumes are small. Rooftop commercial solar has enough UK installations for cost statistics to mean something. Car park canopies do not, so there is no dataset to average. Where industry figures exist they tend to come from suppliers quoting their own ranges, which is marketing rather than measurement.
The biggest cost is not the canopy. On a car park that earns money or that staff depend on, the parking taken out of use during construction can exceed the build cost. That figure is specific to your site and your charging regime, so it cannot appear in anyone’s price list — and its absence makes every published band optimistic.
The one figure with workings
When DESNZ consulted on requiring solar canopies on new car parks, it published an illustrative appraisal for an 80-space car park. The numbers it used, approximately:
| Line | Figure |
|---|---|
| Installation | £140,000 |
| Annual energy saving | £28,000 |
| Annual EV charging revenue | £22,000 |
| Annual maintenance | £1,400 |
| Foregone parking revenue (3.5-month closure) | £180,000 |
Two things make this worth more than any commercial band. First, you can derive a unit cost and check it: 80 bays at roughly 1.7 kWp per bay is about 136 kWp, so £140,000 is in the order of £1,000 per kWp. Second, and more important, the foregone parking was the largest number in the government’s own case — larger than the installation. Any model that stops at the capital figure has omitted the biggest line.
The proposal to mandate canopies was not taken forward, which the government confirmed on 21 May 2026. The appraisal remains the most transparent public worked example of a UK car park canopy, which is a slightly embarrassing state of affairs for the industry but useful to know.
How to compare three quotes without a benchmark
If there is no market price, the only defence is making the quotes commensurable. Six questions do most of the work:
- Is the foundation cost fixed or provisional? If no one has seen ground data, every foundation figure is an estimate. The quote that says so is the honest one, and it will often look more expensive for exactly that reason.
- What grid scope is included? The G99 application, the network operator’s own charges, any reinforcement contribution, metering, and the AC works from inverter to distribution board. Reinforcement is the item most often excluded and the most expensive to meet late. Note that every commercial canopy is G99 — G98 caps at 16 A per phase — so a quote describing a “G98 notification” for a canopy has misread the connection rules, as our installing a solar canopy guide sets out.
- What phasing is assumed? A price based on a closed car park is not comparable with one based on working section by section. Ask each supplier to state bays out of use and for how long.
- Is surface reinstatement in scope, and to what finish? “Make good” means something very different on tarmac and on block paving.
- Which structural design is priced? Calculations for your site’s wind and snow loading, or a generic type approval for the product range? If the latter, the price is provisional whatever the covering letter says.
- What is the unit of comparison? Compare cost per bay covered as well as cost per kWp. Bays are what you have; kWp is derived from an assumption about modules per bay. Two quotes at the same price per kWp can differ by a third per bay because one assumes a denser layout than will physically fit.
That last point is where most of the hidden variance lives. A standard UK bay is 2.4 m by 4.8 m — about 11.5 m² — and a 430 W module is about 2 m². Four modules per bay is realistic after beams, gutters, setback and access; roughly 1.7 kWp per space. A supplier implying 3 kWp or more per bay is assuming about eight modules over 11.5 m², which does not fit, and their price per kWp will look excellent until you count the bays.
What a sensible budget process looks like
Commission the ground investigation before accepting a price, and issue the result to every bidder so they all price the same ground. Submit the G99 application at the same time — it costs nothing and it is usually the critical path. Then ask for quotations with separate lines for foundations, structure, electrical plant, grid works and EV infrastructure.
Separated lines are not pedantry. They make the quotes comparable, they expose a provisional sum wearing a fixed-price label, and they matter later: the business rates exception applies to the generation plant, and whether a canopy’s steel frame is rateable is addressed nowhere in published guidance — explained on our solar canopy business rates page. The same unresolved boundary runs through the capital allowances question.
For an independent starting figure, get an instant estimate — indicative capacity from your bay count, modelled generation for your location, the consent route and the grid position, by email.