How Much Power Does a Solar Carport Generate Per Bay?
About 1.5 kWp fits over a standard parking bay, and a shallow-pitched canopy in the UK returns roughly 730 to 950 kWh for every kWp installed. That puts a single bay between 1,100 and 1,420 kWh a year — and the city you are in moves it by a third.
Start with capacity per bay, not panel count
At commercial scale a car park sizes at approximately 1.5 kWp per parking bay once you allow for column lines, drive aisles and accessible bays. A 60-bay staff car park is therefore about 90 kWp, 120 bays about 180 kWp, and 200 bays about 300 kWp. Panel wattage changes how many modules make up that figure; it does not change the roof area you have to work with.
Then use the canopy's own pitch
This is where most estimates go wrong. A canopy is pitched shallow, around 10°, to keep clearance and wind loading sensible. Modelled on PVGIS v5.3 (SARAH3 2005–2023, 14% losses, free-standing, south-facing), a 10° canopy returns about 946 kWh/kWp a year in Cardiff, 920 in London, 875 in Birmingham, 807 in Manchester, 805 in Edinburgh, 791 in Aberdeen and 772 in Glasgow. That is 9.5–11.5% below the same array at 35°. A stated yield of 1,000–1,100 kWh/kWp for a UK car park overstates generation everywhere, and by about a third in the Highlands.
Per bay, in round numbers
Multiply through: at 1.5 kWp per bay, a bay generates about 1,420 kWh a year in Cardiff, 1,380 in London, 1,310 in Birmingham, 1,210 in Manchester and 1,160 in Glasgow. For a 200-bay scheme that is roughly 284,000 kWh in Cardiff against 242,000 kWh in Manchester — same steel, same panels, 17% difference in output.
Self-consumption decides what it is worth
Generation is not saving. Units used on site displace the full import tariff; exported units earn an export rate that is typically a fraction of it. A car park attached to a building with steady daytime demand — a supermarket, a hospital, a factory on day shift — captures most of the output. A school car park runs into the six-week summer break falling across the highest-yielding months, so model it on a term-time profile rather than an annual average.
And December decides battery sizing
At 10°, December returns about 21.6 kWh/kWp in London, 10.5 in Glasgow and 7.4 in Inverness. Winter generation cannot refill a battery, so any storage sized on an annual average will disappoint between November and February; size it against the tariff instead. The full cost and payback picture, including the tax treatment, is on the solar carport cost page.
Read Next
Who Can Use Chargers Funded by the Workplace Charging Scheme?
The Workplace Charging Scheme pays £500 a socket, and state-funded schools £2,000 — but who is allowed…
4 min readHow Many Solar Panels Fit Over One Parking Bay?
Bay count, not floor area, is what sizes a car park array — and the answer sets the kWp, the generation and the grid app…
4 min readWill Your Car Park Take the Weight of a Solar Carport?
The question that decides whether a canopy is cheap or expensive is underground. What the foundations have to do, why a …
7 min readWhich UK Car Parks Actually Suit Solar? A 7-Point Screen
Most car parks can take a canopy. Far fewer should. Seven checks that separate a scheme that pays from one that merely w…
Related reading: how to choose a solar carport installer · solar EV charging canopies · the Class OA planning route.
Get an indicative figure for your own car park
Send the details below and we reply by email. The answers help us reply with something relevant to your site.
Solar Car Parks is an independent information site published by SEO-DONS LTD. We are not an installer. We use your details to answer your enquiry; see the privacy notice.