Charging your EV with solar panels

How solar charging works

A solar-aware charger watches how much power your home is importing from or exporting to the grid, using a CT (current transformer) clamp fitted round the supply cable at the meter. When panels produce more than the house uses, the charger raises the car’s charging rate to soak up the surplus. When the sun fades it lowers the rate or stops.

Two kinds of mode exist:

• Surplus only: the charger charges only from spare solar and pauses when it would have to import. The zappi calls this Eco+, Ohme Solar Only and Hypervolt Super Eco.
• Blended: solar tops up with grid power so the car keeps charging. These are the zappi’s Eco, Ohme’s Solar Boost and Hypervolt’s Eco.

There is a minimum. Ohme’s Solar Only starts at 1.44kW (6A) of surplus, Solar Boost from 0.72kW plus grid power, Indra when export reaches 1.4kW, and Easee needs at least 6A. Six amps at 230V is about 1.4kW, so a cloudy spring day can sit below the threshold all day. A car that is not at home and plugged in cannot use any of it.

Which chargers support solar

Notes from manufacturers’ pages (read 10 October 2026):

• myenergi zappi: Eco, Eco+ and Fast. A grid CT clamp with a 5m cable is in the box, three on the three-phase model. The surplus-only Eco+ is why it is the usual solar recommendation. Charger only from £779; see our zappi review.
• Ohme Home Pro and ePod: Solar Only and Solar Boost, needing a working CT clamp and a charger installed from January 2023 onwards; Ohme says some older chargers may not be eligible. Installed from £999; see the Ohme Home Pro review.
• Hypervolt Home 3 Pro: Boost, Eco and Super Eco, plus a Battery Safe mode so the charger does not drain a home battery. The primary CT clamp is supplied and a second, sold as an extra for £25, is needed for Battery Safe. See the Hypervolt review.
• Andersen A3: a solar CT clamp, with a solar integration package in its standard installation, and a per-session choice of how much solar to use.
• Indra Smart PRO: a solar mode using the CT clamp in the box, starting only when export reaches 1.4kW.
• Easee One: surplus charging needs the Easee Equalizer at £129.99, plus a meter kit in homes without a compatible port. Modes are Surplus only and Limited grid usage.
• Wallbox Pulsar Max: solar charging is an optional feature that needs an external Wallbox power meter.
• Pod Solo 3S: has a solar mode; whether a CT clamp is needed was not stated, and charging from solar does not earn Pod Rewards.
• EO Mini Pro 3: a separate solar CT input, with solar matching topped up from the grid. EO Charging’s maker went into administration in April 2026, so check support before buying.
• Zaptec Go 2: supports solar integration through the ev.energy app in the UK. Hardware needs are unconfirmed.
• Tesla Wall Connector: no solar mode is advertised.

If a charger needs a CT clamp bought separately, DNOs estimate £30 to £50. Our CT clamp guide covers fitting.

How much solar covers

Solar output swings with the seasons. We modelled a 4kWp south-facing roof at 35 degrees with no shading, using the European Commission’s PVGIS tool (SARAH3 radiation data averaged over 2005 to 2023, 14% system losses) at London, Birmingham and Glasgow. We set it against the 236 kWh a month an average battery-electric car uses (9,400 miles at 0.301 kWh a mile).

In June, the modelled roof produces about twice the car’s average monthly need. In December it produces 32% (Glasgow) to 62% (London) of it. About two-thirds of the year’s output comes between April and September: 68% in Birmingham, 67% in London and 72% in Glasgow.

Per day, Birmingham averages about 15.6 kWh in June, enough for roughly 52 miles at 0.301 kWh a mile if every kWh reached the car, and about 4.3 kWh in December, about 14 miles. That is the ceiling. Whether the car gets any of it depends on when it is home and plugged in, and on what the house uses first. We found no sourced UK figure for how much of a home’s generation a car typically absorbs, so we do not give one. A driver who commutes by car and charges after work will use little summer midday surplus; someone home during the day will use much more.

Export or self-use: the maths

Using a solar kWh in the car means you do not export it. The gain is the import price you avoid; the cost is the export payment you give up.

You are better off exporting when the export rate is higher than the import price you avoid. Ofgem says Smart Export Guarantee rates “must always be above zero” and each supplier sets its own, so we have no verified rate to quote. Check yours.

The avoided import price depends on your tariff:

On a standard tariff, using solar in the car beats nearly any export payment. On a cheap overnight tariff the avoided cost is small, because you would have charged that kWh at the night rate anyway. Octopus says this too: it advises against solar-divert settings on Intelligent Octopus Go and recommends letting surplus export. As an illustration only, with an assumed 15p export rate (our assumption, not a quote), diverting 10 kWh into the car saves 10 × 7.6p = 76p of night-rate import but gives up 10 × 15p = £1.50 of export.

Octopus bills Intelligent Octopus Go customers only for what the smart meter imports, so solar charging of the car is not billed, and on a sunny afternoon with zero import the bill is zero and that time does not count towards the six-hour cap. Octopus says Outgoing Octopus and the Smart Export Guarantee both work with Intelligent Octopus Go. Octopus’s Go page says Octopus Go can only be paired with certain export tariffs.

Solar with a smart tariff

Smart tariffs and solar modes compete for control of the charger:

• Intelligent Octopus Go: Octopus advises blinding a home battery to the car charger so it does not feed the car, and it enrols you in a flexibility service that rules out joining another. Hypervolt’s solar modes are unavailable during Octopus-managed windows, when the charger runs in Boost. With an Indra on an IOG charger integration, “Use Solar” adds solar charging around Octopus’s schedules. Octopus says Intelligent Octopus Go usually beats its Flux tariff if you have solar, a battery and an EV, depending on mileage.
• EDF GoElectric: seven hours at 6.66p gives a home battery the widest fixed cheap slot, but it is fixed-window and the solar charger works alongside it.
• British Gas: EV Power works with solar. Charge Power is half-price from midnight to 5am for homes with an EV, a battery and solar, with the full standing charge still payable.

See our EV tariff comparison and Intelligent Octopus Go guide.

Which charger should you choose?

This is analysis from specifications and published owner reports, not testing.

• Solar first: the zappi, for surplus-only Eco+ and the clamp in the box.
• Solar plus a home battery: the Hypervolt Home 3 Pro, for Battery Safe, but remember its solar modes pause under Octopus control.
• Intelligent Octopus Go first, solar second: Ohme, which is generally available on the tariff and cheaper installed than the Hypervolt or the Andersen.
• Installation bundle: Andersen includes the solar package in its standard install.

Compare fitted prices on our best home EV chargers roundup.