Which UK Car Parks Actually Suit Solar? A 7-Point Screen

1. Does the site use electricity when the sun is up?

This is the screen that decides most cases. Self-consumed generation is worth the full retail rate; exported generation earns the lower Smart Export Guarantee rate. A car park serving a weekday daytime load self-consumes; one serving an evening or weekend operation exports. The same canopy can have very different economics on two sites a mile apart.

2. How many bays, and are they in one block?

At about 1.5 kWp per bay, scale drives the unit cost down — but only if the bays are contiguous. Three separated areas of 60 bays cost more per kWp than one block of 180, because each needs its own structure, cabling run and often its own connection point.

3. What does the DNO say?

Every car park array is a G99 connection — G98 stops at 16 A per phase, roughly 3.68 kW per phase. The connection offer can carry a cost, a curtailment condition or a queue position, and that answer governs the scheme. Ask early.

4. Is it England, and is it an existing car park?

In England a canopy over an existing off-street car park is permitted development subject to prior approval under Class OA, 4 metre limit, 56 days to determine. Wales has no equivalent right, so a Welsh scheme is a full application. Article 4 directions and conservation-area status can remove the right anywhere.

5. What is underground?

Made ground, a high water table or buried services change the foundation type and the column grid. A ground investigation before pricing turns the largest cost variable into a known number.

6. Who owns the car park, and for how long?

A lease shorter than the asset life changes the funding route — and under a power purchase agreement the capital allowances sit with the funder, not the occupier, which should be reflected in the tariff offered.

7. Is the tax position modelled correctly?

Solar is special-rate plant: it cannot claim full expensing, and the Annual Investment Allowance gives 100% of qualifying plant in year one up to £1m. In England on-site renewables plant is out of rateable value to 2035. Public-sector sites should note the Public Sector Decarbonisation Scheme closed to new applications in November 2024. A screen that gets the tax wrong flatters or kills a scheme for the wrong reason — the overview for solar car parks sets out how the pieces fit together.

Related reading: bifacial car park panels · school and university car parks · commercial solar canopy systems.