100kW Solar Carport Cost UK (2026): Bays & Payback

Cost item	Typical range (100 kWp)	What is included
Steel structure and foundations	£40,000–£63,000 (~45% of total)	Galvanised steel frame engineered to Eurocode 1 (BS EN 1991) for wind and snow, plus foundations — ground screws on ~90% of sites, or ballasted/piled where ground demands
PV modules	£15,000–£25,000	~220–230 panels at 450W (bifacial adds ~5–12% generation for a modest uplift)
Inverters and cabling	£8,000–£14,000	String inverters, DC/AC cabling, isolation and metering to BS 7671
Electrical works and DNO connection	£9,000–£18,000	G99 grid application (~4–8 weeks), containment, on-site electrical install under CDM 2015
Design, surveys and planning	£6,000–£12,000	Structural design, glare/glint study, SuDS drainage strategy, and the Class OA prior-approval application (England)
Optional: EV charging	£1,000–£2,500 per 7–22kW AC socket	Workplace/destination AC chargers under the canopy (not standalone 50kW+ DC rapids — those need grid + battery)
Total, 100 kWp installed	~£90,000–£140,000	Turnkey: structure, PV, electrical and DNO connection under one contract — not a bare frame

A 100 kWp solar carport is the sweet spot for a lot of UK sites: big enough that the fixed cost of the steel spreads efficiently, small enough to sit comfortably under England’s permitted-development route. It covers roughly 50 standard parking bays and, at the UK average yield, generates around 90,000–95,000 kWh a year. Here is what it costs, what it saves, and how the funding and planning stack up in 2026.

What a 100kW solar carport costs

At commercial scale, elevated solar canopies and carports run £900–£1,400 per kWp installed. For a 100 kWp system that puts the all-in figure at roughly £90,000–£140,000. Smaller or more complex builds — tight sites, awkward groundworks, architectural finishes — sit higher at £1,200–£3,000/kWp, but a clean 100 kWp scheme on reasonable ground should land inside the commercial band. For comparison, the same capacity as a rooftop array would be £700–£1,050/kWp; the gap is the structure you are buying.

Priced per bay, a solar carport costs about £6,000–£12,000 per bay installed. A 100 kWp system is around 50 bays, since a standard bay carries roughly 2 kWp — four to six 450W panels over about 12 m². A double-sided, back-to-back layout can lift that toward ~4 kWp per bay, so if your car park is larger you may reach 100 kWp across fewer rows.

The single most important pricing fact is that the steel structure and foundations are around 45% of the cost, and that portion is largely fixed engineering work. So the more capacity you spread it across, the lower your £/kWp. A 100 kWp scheme is well up the curve — considerably better value per kWp than a 20-bay canopy, and approaching the efficiency of a 100-bay car park. See the full cost breakdown for how the ranges shift with scale.

What 100kW generates and saves

At the UK average yield of 900–950 kWh per kWp, a 100 kWp canopy produces roughly 90,000–95,000 kWh a year (more on the south coast, less in northern Scotland). Bifacial panels, which pick up light reflected off the ground and cars, add around 5–12% on top.

The money comes from self-consumption. Self-generated solar costs about 10p/kWh over its life, against grid electricity for a business at 25–47p/kWh. Every unit you use on site instead of exporting is worth roughly twice as much — self-consumed solar is worth about 2x exported solar. On a site with steady daytime demand (offices, retail, clinical, light industrial), it is realistic to self-consume most of the generation, with the surplus sold under the Smart Export Guarantee at roughly 1–15p/kWh.

For a real-world anchor: DESNZ modelling from May 2025 found an 80-space car park could save around £28,000 a year through self-consumption, and the Princess Royal Hospital in Telford is building a 200 kW car-park canopy backed by £445,000 of Great British Energy funding, projected to save about £35,000 a year from early 2026.

Worked payback example

Take the mid-point: a 100 kWp canopy at £1,150/kWp is about £115,000. Generating ~92,000 kWh a year, if you self-consume most of it at a grid price of ~35p/kWh, the displaced electricity is worth in the region of £25,000–£30,000 a year before export income. On those numbers the gross payback sits in the 8–12 year band we quote for solar-only carports — and that is the honest figure.

We will not quote a five-year solar-only payback on a canopy. You are paying for an engineered steel structure as well as the panels, so the break-even is longer than a rooftop’s 4–6 years. Anyone promising five years is either ignoring the structural cost or hoping you won’t check.

What shortens it is EV charging under the canopy: feeding on-site solar at ~10p/kWh into 7–22kW AC chargers that would otherwise draw grid power captures the full price spread, pulling payback into the 7–11 year range. One honest limit: a canopy powers AC charging and lighting well, but it does not run standalone 50kW+ DC rapid chargers on its own — those need a grid connection plus battery storage. See our solar carports and car parks page for how the pairing works. After payback, a Eurocode-engineered canopy is a 25-year-plus asset producing near-free electricity, plus shade, weather protection and EV-ready infrastructure.

Tax and funding: what actually applies

For a business buying outright, capital allowances are the biggest lever — and this is where a lot of incorrect advice circulates.

• Annual Investment Allowance (AIA). A £115,000 canopy sits comfortably inside the £1m AIA, so the whole qualifying spend can attract 100% relief in year one. This is the practical route for almost every single-site 100 kWp scheme.
• 50% First-Year Allowance. Solar PV is a special-rate (“integral features”) asset, which means it is excluded from 100% full expensing. If anyone tells you a solar carport qualifies for full expensing, they are wrong. The 50% FYA is the relevant relief on any spend above the AIA cap.
• Business rates. On-site renewable generation is exempt from business rates in England to 31 March 2035.
• VAT. Domestic solar carries 0% VAT to 31 March 2027; whether that extends to a standalone canopy in a domestic curtilage is not confirmed by HMRC, so check your specific case.
• Grants that are open. The Workplace Charging Scheme runs to 31 March 2027 (up to £500 per socket, £2,000 for state-funded education, 75% of cost, up to 40 sockets). Great British Energy capital is available for the NHS and schools, and Salix offers 0% loans. See grants and funding for the current picture.

Where the capital isn’t there, a Power Purchase Agreement (PPA) flips the maths: a funder designs, pays for, installs and owns the canopy, and you simply buy the power at a fixed rate below grid over 10–25 years — zero upfront, off balance sheet. You forgo the allowances and export income, but get the cheaper electricity and the shaded, EV-ready car park from day one. Buy it outright and you own the asset, claim AIA and FYA, and keep all the savings over a longer break-even.

Planning and grid

In England, a 100 kWp canopy usually falls under the Class OA permitted development right (in force since 21 December 2023) for non-domestic, off-street parking. That means a prior-approval application on siting, design and glare — not full planning. The limits: no part over 4m high, more than 10m from any dwelling, excluding listed buildings and scheduled monuments, with a SuDS run-off condition, and you must start within three years. This is England only — Wales, Scotland and Northern Ireland still need standard planning permission.

On the grid side, a 100 kWp system is well above the 3.68kW/phase G98 threshold, so it needs a G99 application to the DNO — typically 4–8 weeks. MCS certification is required to claim the Smart Export Guarantee.

Get a fixed price for your car park

The only way to know your number is to model it against your actual half-hourly consumption. As a turnkey, MCS-certified installer we deliver the structure, PV, electrical and DNO connection under one contract — with MCS, NICEIC, RECC and TrustMark accreditation and an IWA-backed workmanship warranty. Request a free quote or call +44 7707 970661 for a costed proposal on your site.