Yes, you can charge an electric car with solar panels. Your solar system supplies electricity to your home, and some of that power can run the EV charger. A charger with a suitable solar-surplus mode can adjust charging to use electricity that would otherwise go back to the grid.
The useful question is how much of your driving it can cover. That depends on when the car is plugged in, how much spare solar you have and how the charger is set up. You don’t need a home battery to get started, and you shouldn’t assume that a sunny roof means every charge will be free.
How solar EV charging works
In a normal grid-connected installation, the panels feed an inverter, which converts their electricity for use around the home. The charger is connected to the home’s electrical system. It doesn’t need a separate set of panels reserved for the car.
Imagine your solar inverter is supplying 3.5 kW while the rest of the home uses 0.7 kW. That leaves 2.8 kW available for charging. If the car draws 7 kW, the grid supplies the remaining 4.2 kW, assuming no home battery is contributing. Seeing solar generation in an app doesn’t prove the whole charge is solar-powered.
A surplus-aware charger can vary its demand instead. Ask for the proposed charger, metering and settings to be explained together when comparing home EV charger installations.
Why a solar charger sometimes waits
A small amount of spare generation may be too little to start charging. Myenergi’s zappi charging-mode guidance explains a minimum current of 6 A: roughly 1.4 kW for single-phase charging, or 4.2 kW when charging on three phases.
The mode matters. On zappi, ECO can top up insufficient solar with grid electricity. ECO+ with Minimum Green Level at 100% can pause when surplus is too low; a scheduled boost can still use grid power. Other chargers have their own controls, so check the exact model rather than relying on a “solar compatible” label.
That pause isn’t necessarily a fault. Switching on an appliance reduces the spare power available to the car. Decide whether your priority is using surplus only or reaching a required charge by a particular time.
How much driving could the panels cover?
Start with miles driven, not the size of the car’s battery. A car with a large battery doesn’t need a full recharge after every trip.
Here’s an illustrative daily calculation, not a forecast for a particular vehicle or roof. Assume 30 miles of driving, efficiency of 3.5 miles per kWh taken from the vehicle battery, and 90% efficiency from the home’s AC supply into that battery:
30 ÷ 3.5 ÷ 0.90 = about 9.5 kWh supplied to the charger.
Now assume the roof provides an average 2.5 kW of spare power for four hours while the car is connected. That’s 10 kWh at the charger, about 9 kWh stored under the same loss assumption, and roughly 31.5 miles of driving. These are deliberately simple assumptions: weather, vehicle temperature and charging conditions can change the result.
The distinction between kW and kWh matters here. kW is charging power at a moment in time; kWh is the energy delivered over a period. A 7 kW charger does not need seven solar panels, and an array’s peak rating is not its all-day output.
For example, ten 470 W panels have a combined rating of 4.7 kWp. Their actual generation depends on the roof, shading and conditions. The Energy Saving Trust’s solar guide explains the factors affecting performance. A solar installation proposal should assess your home and car together, with seasonal generation estimates rather than just an annual total.
Will your car be home when the solar is available?
If you work from home, work shifts or regularly leave the car on the drive during daylight, direct solar charging may fit your routine well. A few useful hours across the week can matter more than one perfect sunny day.
If the car leaves early and returns after dark, direct weekday solar charging has little opportunity. Weekend charging can still help, but don’t size a system around daytime charging that won’t happen.
Before requesting a quote, note your usual departure time, return time, weekly mileage and the charge you need for the next journey. If you already have solar, bring generation and export records too. Export data helps show how much electricity is left after the home has used its share.
Do you need a home battery as well?
No. Solar can supply a connected car during generation without being stored in a home battery first. Storage becomes a separate decision when you want to keep daytime energy for later. The Energy Saving Trust’s storage guide recommends weighing potential savings against installation cost and battery life.
Don’t assume a household battery will fill an EV overnight. Compare its usable energy and discharge power with the car’s needs, allow for conversion losses, and leave enough for any household demand you want it to cover. Ask how the charger and battery controls will work together so charging the car doesn’t unexpectedly empty the home battery.
If you already have storage, share the inverter and battery model numbers before choosing a charger. Our battery storage service can be considered alongside the charging design, rather than treating the two systems independently.
Solar charging isn’t always the cheapest option
Using your own generation avoids buying electricity at that moment. But if you receive payment for metered exports, it also means giving up that export income.
Compare your actual export payment with the import price you could use to charge later. Octopus Electric Vehicles’ solar-charging guide explains why exporting and charging at a cheaper time can sometimes cost less. Check your current agreement, eligibility and import/export compatibility before switching. A saving from changing tariff should not be presented as a saving created by the panels.
Before choosing your charger
Ask the installer to confirm solar-surplus control, vehicle compatibility, electrical supply capacity, cable reach and any extra metering required. Also ask who controls the charging schedule: the car, the charger or an energy supplier’s app. Agree how those settings will interact.
Charging speed is limited by the vehicle as well as the chargepoint. The Energy Saving Trust’s EV charging advice also covers installation and registration with the local electricity network operator. A higher advertised charger rating alone doesn’t guarantee a faster charge at your property.
Sunergy Renewables is based in Nuneaton and serves homeowners across Warwickshire, Leicester, Leicestershire and the wider Midlands. Ask us about solar and EV charging for your home. Send your postcode, car model, usual charging routine and details of any existing solar or battery equipment so we can assess a setup that fits.
