Should your business install solar, batteries and EV charging together?

A combined project can serve vehicles and building demand, but the energy flows and funding contracts must agree. Eligible chargepoint installations can receive up to £500 per socket under the Workplace Charging Scheme [S3]. Start with your consumption and parking pattern, then test low, mid and high use. Solar generation alone does not establish charging income. Checked October 2026.

Last checked 16 October 2026

Why combine solar panels, battery storage and EV charging?

Consider a combined design when the same site needs vehicle energy, building electricity and control of peak demand. Ask the designer to show how each item contributes. A battery should solve a defined timing or power problem, rather than appear in the quote simply because solar and chargers are being installed.

Kilowatts, or kW, measure power. Kilowatt-hours, or kWh, measure energy. Solar photovoltaic panels, or PV, generate electricity; a battery stores it. The battery’s usable kWh and discharge kW answer different sizing questions. Put both in the specification, alongside the vehicles’ required departure energy.

DfT recorded 121,171 public EV chargers on 1 July 2026 [S4]. That gives national context, but your decision needs evidence of your own demand. Count arrivals, parking duration and opportunities to charge during solar hours. An office daytime fleet and a night-returning depot need different energy schedules.

How should you set up solar charging and battery controls?

Request an electrical diagram and an operating schedule covering sunny trading hours, dark evenings and vehicle charging overnight. Ask which controller decides where energy goes when several demands coincide. Include a test that checks whether the stationary battery is deliberately serving the vehicles or being reserved for a later building peak.

Use distinct energy lines in the model: direct solar use, solar stored and later delivered, grid purchases and exports. Assign each unit once. Our smart charging guide explains timetable comparisons. Read battery costs before paying for extra storage whose operational purpose has not been shown.

Which funding model fits your combined project?

Compare the whole arrangement, including access and energy rights. These descriptions explain the funding models; an actual proposal needs written terms.

In a combined offer, ask who receives export payments and who sells solar electricity to the building. Request lease length, tariff-setting rights, maintenance, insurance, business rates allocation and exit terms. Ask your solicitor to check redevelopment, assignment and reinstatement obligations before signing.

What could the site earn, and how many years until payback?

This is an illustration, not a quote. All inputs below are assumptions, not sourced market prices or a prediction of solar yield. The model deliberately prices all vehicle energy as grid purchases. Solar supplies only a separate building load, so there is no double counting of charging margin and avoided imports.

Annual sales energy E = sessions/day × 20 × 365. Charging margin = E × (£0.45 − 1.10 × £0.20) − £1,200. Building benefit = 10,000 × £0.20 − £500 = £1,500. Total annual net project value is the charging margin plus that building benefit. Here, net value includes avoided purchases; it is not all cash revenue.

For the mid case, E = 29,200; net project value = 29,200 × £0.23 − £1,200 + £1,500 = £7,016. The part funded host gets half, £3,508. ROI = annual net ÷ host capital × 100. Payback = host capital ÷ annual net. The identical percentage ranges follow from assuming half the capital and half the net value.

The fully funded host receives E × £0.45 × 10%; it receives no building benefit in this assumed contract. In practice, document how any building benefit is credited or shared. The illustration excludes finance, tax, grants, degradation, replacements, insurance, rates and land costs. Add them before making a decision.

What does the site need before installation?

Ask the distribution network operator, or DNO, to assess the full connection proposal. G99 is an engineering recommendation for generation connections outside the qualifying G98 route [S1]. Charger demand needs its own assessment [S2]. See G98 versus G99.

Request a layout preserving accessible routes, deliveries and emergency access. Have the designer identify planning and landlord checks. HSE explains risk assessment duties for grid-scale battery systems; obtain a site-specific safety assessment rather than treating that guidance as a small-system layout specification [S5].

The Workplace Charging Scheme offers eligible installations up to £500 per socket, subject to its cost cap and eligibility rules, and runs until 31 March 2027 [S3]. Check eligibility before ordering. No grant is deducted in the illustration. Check tax treatment with your accountant.

HMRC lists qualifying new and unused EV charging equipment for first-year allowances [S6]. An allowance reduces taxable profits; it does not reimburse the equipment invoice. Keep any tax calculation separate from the operating example and have your accountant check eligibility.

What should you do next?

Collect your consumption records and vehicle timetable, then get matched with an installer that covers your area for a combined design and operating model.

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