Solar + EV Charging FAQs

On the solar side there is an official figure: DESNZ’s 2025/26 data put the average non-domestic 10–50 kW system at £1,167 per kW installed, so a 50 kW roof array is roughly £58,000 at that average. Charger cost depends on charger type, groundworks, distance from the supply, and software, and has no official price series. The cost guide works through an example, and the workplace EV charging costs guide covers charger-only budgets.

It depends on when the vehicles are parked and whether the building uses the rest of the array’s output. At the prices used on this site (£1,167 per kW, 24.14p grid power, 5p export), a London array used only by vehicles pays back in about 7.8 years for a workplace fleet with solar-following control, 17.1 years if chargers start on arrival, and 23.2 years for vehicles parked overnight; if the building uses every kWh the figure is 5.3 years. See the break-even test and the EV charging cost calculator.

At 24.14p per kWh (the Q1 2026 average non-domestic price) against Zapmap’s August 2026 averages of 54p and 77p, a car using 0.294 kWh a mile costs about 7.1p a mile on your own supply against 15.9p and 22.6p in public — 55% and 69% less — before any solar.

The Annual Investment Allowance gives 100% relief on up to £1 million of qualifying plant a year, including solar, which is special-rate plant (companies above that cap get a 50% first-year allowance on the excess; solar cannot claim full expensing). New, unused chargepoints qualify for a 100% first-year allowance until 31 March 2027 for companies (5 April 2027 for income-tax payers). Commercial installations carry 20% VAT, normally recoverable by a VAT-registered business. The capital allowances guide sets out the order of claims.

Yes: free, subsidised and per-kWh pricing are all possible. Free workplace charging offered to employees generally is not a taxable benefit for them (ITEPA 2003 s237A); charging a tariff is a sale, with VAT if you are registered. The tax rules for employee charging are set out in the blog.

Often, if charging is managed. Twenty vans needing about 552 kWh a night average about 46 kW over a 12-hour window, against 140 kW if every 7 kW socket ran at once. Dynamic load management holds total demand under the supply limit; where that is not enough the network operator quotes for more capacity. The grid connection guide sets out the process.

Almost always: G98 covers installations up to 16 A per phase (3.68 kW single-phase) and anything larger needs G99, which means applying to the network operator and receiving agreement before connecting. A vehicle-to-grid charger or a battery that can export is a generating unit too. See grid connection for solar and EV charging.

It depends on the nation and the equipment. Roof-mounted solar on non-domestic buildings is generally permitted development in England (Part 14, Class J, whose 1 MW cap was removed on 21 December 2023), subject to conditions and exclusions such as listed buildings; Scotland and Wales have their own rules. A solar canopy over an existing non-domestic car park is permitted development in England under Class OA, but always subject to a prior-approval application (56 days) and not within 10 m of a dwelling, above 4 m, or within the curtilage of a listed building. Wales has no equivalent, so a canopy there needs planning permission; Scotland’s Class 9M allows car park canopies under conditions such as not within 5 m of a road. For chargers in England, a wall outlet up to 0.2 cubic metres or a free-standing upstand up to 2.7 m (one per parking space) is permitted development, with one equipment housing of up to 29 cubic metres allowed in non-domestic car parks. Always confirm with your local planning authority.

The Electric Vehicles (Smart Charge Points) Regulations 2021 set smart-functionality and security requirements for charge points sold for home and workplace use in Great Britain. In practice reputable 2026 commercial hardware ships compliant and your installer should evidence it. Specify OCPP on top, which the regulations do not require but vendor independence does.

It is promising and proven in trials, but not yet a default specification: vehicle compatibility is model-specific, bidirectional hardware carries a price premium, and revenue depends on supplier or aggregator contracts. Because a bidirectional charger can export, it is treated as generation for grid purposes. Build V2G-ready (OCPP, duct capacity) on today’s economics; the V2G page covers the position.

Three inputs: twelve months of half-hourly meter data, your vehicle or staff-charging expectations (counts, schedules, mileages) and the site address. The free feasibility on this site turns those into array size, socket plan, load-management approach, grid position, grant eligibility and cash flow in writing within seven working days (ask for it on the quote page); for a first pass, the calculator runs the numbers in your browser.