The EV Charging Business Case for UK Businesses in 2026
The EV charging business case rests on a price gap: in 2026 a business paid about 24p/kWh for grid electricity, public chargers charged 54–77p/kWh, and on-site solar produced power for roughly 5–6p/kWh of capital cost. This page builds the case line by line, with the source for every figure and every assumption marked as one.
The price gap the whole case rests on
Every EV charging business case, whether it is staff sockets in an office car park or a depot full of vans, comes down to which of four prices a vehicle's electricity is bought at:
| Where the kWh comes from | Price per kWh | Source |
|---|---|---|
| Public rapid/ultra-rapid charger (50 kW+) | 77p (pay-as-you-go average, Aug 2026) | Zapmap Price Index |
| Public standard charger (3–49 kW) | 54p (Aug 2026) | Zapmap Price Index |
| Your own site, from the grid | 24.14p average incl. CCL (Q1 2026) — use your own bill's unit rate | DESNZ Quarterly Energy Prices, table 3.4.2 |
| Your own site, from your solar array | about 5.4–6.4p capital cost over 25 years | Our arithmetic from DESNZ 2025/26 cost data (£1,167/kW) and PVGIS yields |
Zapmap translates its two public prices into roughly 16p and 23p per mile for an average-efficiency electric car. At the same efficiency, grid-fed workplace charging is about 7p a mile and solar-fed charging under 2p. The EV charging business case is the process of moving as many of a site's charging kilowatt-hours as possible down that table — first from public networks onto the site, then from the grid onto the array.
Line one: vehicle energy off public networks
For fleets, this is usually the biggest number. A vehicle that charges on public networks because it has nowhere to charge at base is paying 54–77p/kWh. The same kilowatt-hour from the site's own supply costs whatever the site's unit rate is. The saving scales with mileage and does not need solar at all — solar then widens it. The cost-per-mile comparison works it through for cars and vans, and the fleet depot guide covers duty cycles where vehicles are away all day and can only charge overnight.
Line two: solar surplus turned into vehicle energy
A five-day business rarely uses all of an array's output on site; the remainder is exported at the export tariff. Chargers that follow the solar surplus convert that export into self-consumption valued at the grid price; the system design guide explains the controller that does it. How much depends on when vehicles are parked: staff cars that sit from nine to five can absorb a lot of midday generation; vans that leave at seven and return at six cannot. In London, a well-angled array produces about three times as much in June as in December, so the solar share of charging is seasonal as well as daily.
Line three: grants and tax
The Workplace Charging Scheme pays up to £500 per socket, capped at 75% of cost and 40 sockets across all your sites, until 31 March 2027. New, unused chargepoint equipment qualifies for a 100% first-year allowance to 31 March 2027 for companies (5 April 2027 for income-tax payers). Solar panels are special-rate plant: they are covered by the £1m Annual Investment Allowance, and companies above that cap get a 50% first-year allowance on the excess — not 100% "full expensing". Allowances are claimed on the cost net of any grant. The capital allowances guide sets out the order of claims.
Line four: what a combined project avoids paying twice
Procured together, the two systems share a supply assessment, one conversation with the DNO about generation and demand, one set of groundworks and one design of the switchgear. We do not publish a percentage saving for this because no dataset measures it; ask each bidder to price the combined scope and the two scopes separately, and the difference is your number.
Line five: the lines outside the payback
Workplace charging made available to all employees at the workplace is not a taxable benefit for them under section 237A of the Income Tax (Earnings and Pensions) Act 2003, which makes it a low-friction staff benefit — the guide to paying for employees' charging covers the conditions. In England, on-site renewable generation and EV chargepoint plant is excluded from business-rates valuations until 31 March 2035. And new non-residential buildings, or major renovations, with more than ten parking spaces must provide at least one chargepoint and cable routes for one space in five under Approved Document S, so some sites are facing a charging project anyway.
A worked EV charging business case you can argue with
An office in the south of England with a 50 kW low-pitch roof, ten staff sockets and a small pool of company cars. The inputs marked assumption are ours — replace them with your own quotes and meter data. The EV charging cost calculator runs your own vehicles through the same arithmetic.
| Input | Value | Basis |
|---|---|---|
| Solar cost | 50 kW × £1,167 = £58,350 | DESNZ 2025/26 non-domestic 10–50 kW mean |
| Solar output | 50 kW × 920 kWh = 46,000 kWh a year | PVGIS, London, 10° pitch |
| Chargers | 10 sockets × £1,500 installed = £15,000 | Assumption — get itemised quotes |
| WCS grant | 10 × £500 = £5,000 | £500 cap binds, because 75% of £1,500 is £1,125 |
| Net capital cost | £68,350 | £58,350 + £15,000 − £5,000 |
| First-year allowances | £68,350 × 25% = £17,088 of tax saved | AIA (solar) + 100% FYA (chargers, net of grant); 25% main rate of Corporation Tax |
| Solar used on site | 80% = 36,800 kWh × 24.14p = £8,884 a year | Assumption on self-use with solar-following charging; DESNZ average price |
| Solar exported | 20% = 9,200 kWh × 5p = £460 a year | Assumption on export tariff |
| Company-car charging moved off public networks | 15,000 kWh × (54p − 24.14p) = £4,479 a year | Assumption on volume; Zapmap standard price vs DESNZ grid price |
On those inputs the annual value is about £13,800 against an after-tax cost of about £51,300 — a simple payback a little under four years, before finance costs, maintenance and back-office fees. Change the self-use share, the export rate or the public-charging volume and the answer moves; the structure does not. Note the model counts the solar kWh that go into cars once, at the grid price, and the public-charging saving separately, on grid-fed kilowatt-hours only.
A model like this is only as good as its inputs. Twelve months of half-hourly data will tell you the real self-use share; the parking rota tells you how much charging can follow the sun. That is what the free feasibility below is built from. For what each line item costs in more detail, see solar EV charging costs.
Where the case is weak
- Low utilisation. Sockets that nobody uses earn nothing. Size to the vehicles you have or have ordered, and duct for the rest.
- A supply upgrade you did not price. If the site needs a larger connection, that cost can outweigh everything above. Test load management first — see grid connection for solar and EV charging.
- Deadlines. The WCS closes to applications at 11:59pm on 31 March 2027 and the chargepoint FYA ends the same day for companies. A project that slips past those dates loses both.
- Vehicles away all day. If vehicles only charge at night, the solar contribution is small without storage; the case then rests on line one alone.
EV charging business case questions
What payback should a business expect on solar EV charging?
It depends on how much of the array's output the site and vehicles use, your own unit rate, and how much charging moves off public networks. On the worked example above — a 50 kW roof and ten sockets — simple payback is a little under four years before finance and maintenance, but the inputs marked as assumptions move it either way.
Does EV charging equipment qualify for capital allowances?
Yes. New, unused chargepoint equipment qualifies for a 100% first-year allowance on expenditure incurred up to 31 March 2027 for Corporation Tax and 5 April 2027 for Income Tax (CAA 2001 s45EA). Solar is special-rate plant, relieved through the £1m Annual Investment Allowance rather than full expensing.
Is free workplace charging a taxable benefit for staff?
No, provided the charging is at or near the workplace and made available generally to employees there (ITEPA 2003 s237A). For company cars, electricity is not fuel for the fuel benefit charge.
Should we install solar first and chargers later?
Phasing can suit a site whose vehicles are years away, but design the electrical infrastructure, ducting and grid plan for the end state. Remember that the Workplace Charging Scheme and the chargepoint first-year allowance both end on 31 March 2027 for companies.
How should solar-powered charging be valued in a business case?
When deciding whether to build the array, use its lifetime capital cost per kWh — about 5.4–6.4p on 2025/26 cost data. Once it is built, value each kWh put into a vehicle at the export payment given up, and the saving at the grid price it replaces.
Sources
- DESNZ, Quarterly Energy Prices, table 3.4.2 (non-domestic electricity prices incl. CCL), Q1 2026.
- DESNZ, Solar PV cost data 2025/26 (TIC basis), published 28 May 2026 — gov.uk.
- EU Joint Research Centre, PVGIS 5.3 (SARAH3 radiation data, 14% system losses).
- Zapmap Price Index, August 2026 averages — zapmap.com.
- Workplace Charging Scheme — GOV.UK Find a Grant.
- First-year allowances for chargepoints — HM Treasury policy paper, 26 November 2025; Capital Allowances Act 2001 s45EA.
- Income Tax (Earnings and Pensions) Act 2003 s237A — legislation.gov.uk.
- The Valuation for Rating (Plant and Machinery) (England) (Amendment) Regulations 2022, S.I. 2022/405.
- Approved Document S — Infrastructure for charging electric vehicles.
Figures checked 27 September 2026. Tax treatment depends on your circumstances; confirm with your accountant before committing. More questions are answered in the solar EV charging FAQs.
Free combined feasibility
Get combined solar + EV charging figures for your site
Tell us about the site and the vehicles. The reply is a written desk feasibility — array size, charger plan, grid headroom, grant and tax position — within 7 working days, from twelve months of meter data if you have it. No site visit is needed for that first pass.