Can You Charge an Electric Car with Solar Panels?

Yes — And It's One of the Best Solar Use Cases

Combining solar panels with an EV charger is one of the most financially compelling home energy decisions you can make. A typical electric car travelling 10,000 miles/year at 3.5 miles/kWh requires approximately 2,857 kWh of electricity. At the current rate of 24p/kWh that's £686 in charging costs. Charge from solar and that cost falls to near zero.

How Solar EV Charging Works

Standard EV chargers draw power from wherever your home gets its electricity — grid or solar. To specifically use solar surplus for charging, you need a solar divert-capable charger.

The Zappi charger by myenergi is the most popular choice. It communicates with a clamp meter on your electricity supply and automatically adjusts the charging rate based on your solar surplus. When the sun is strong, it diverts all surplus generation to your car. When you generate less than the minimum 1.4kW needed to charge, it stops (in Eco mode) or supplements with grid power (in Eco+ mode).

The Zappi in Practice

A Zappi installed on a home with a 4kW solar system and a typical UK driving pattern will typically charge from solar for 4–6 hours on a sunny summer day, adding 15–25 miles of range from free solar electricity. Over a full year, this can cover 2,000–4,000 miles of driving at near-zero cost.

The Zappi's modes:

• Eco mode: Charges using any available solar surplus, supplemented by grid if solar alone is below 1.4kW minimum
• Eco+ mode: Only charges when solar surplus alone can meet the charging demand — no grid supplement. Can take longer in mixed weather.
• Fast mode: Charges at maximum speed from grid, ignoring solar. Useful when you need a quick top-up.

Battery Storage + EV: The Ultimate Combination

Adding home battery storage alongside solar and an EV charger creates the most flexible setup. You can:

• Charge your battery during peak solar hours
• Use stored solar to charge your car in the evenings after the sun sets
• Charge both battery and car from cheap overnight grid electricity (Octopus Go at 7.5p/kWh)

This three-way combination — solar + battery + EV + smart tariff — can reduce your total energy costs (home + car) by 60–75% compared to a standard grid-only setup.

The Numbers: Annual Savings

For a household driving 10,000 miles/year, switching from a petrol car (12p/mile) to an EV charged 50% from solar and 50% from Octopus Go overnight (7.5p/kWh = ~2.1p/mile):

• Petrol car running cost: ~£1,200/year
• EV with mixed solar/cheap grid: ~£200/year
• Annual saving: ~£1,000

Which EV Charger to Choose for Solar?

If solar integration is a priority, the Zappi V2 (myenergi) is our top recommendation — it's purpose-built for solar divert and integrates seamlessly with other myenergi devices. The Ohme Home Pro also has smart tariff integration and is more affordable, though its solar divert capability is less sophisticated than Zappi.

Key Takeaways

• Solar panels can power EV charging for near-zero cost per mile
• The Zappi charger automatically diverts solar surplus to EV charging
• Adding battery storage maximises solar EV charging opportunities
• Combined solar + battery + EV savings commonly exceed £1,200/year
• Octopus Go at 7.5p/kWh provides a cheap overnight backup to solar