Yes, you can charge your electric vehicle using electricity generated by solar panels on your roof. It's one of the most cost-effective and environmentally friendly ways to run an EV. Here's how it works and what you need to know.
How Solar EV Charging Works
The Basic Setup
When sunlight hits your solar panels, they generate electricity. This electricity flows to your home's consumer unit and can power any appliance — including your EV charger.
There are two main approaches:
1. Standard Setup (Grid-Tied)
2. Solar Diversion Setup
Can You Charge Directly from Solar?
Technically, the electricity doesn't flow "directly" from panels to car. It goes through your home's electrical system. But the practical effect is the same — your EV runs on sunshine.
What you need:
Equipment Options
Solar-Compatible EV Chargers
| Charger | Solar Features | Price |
|---|---|---|
| MyEnergi Zappi | Full solar diversion, Eco/Eco+ modes | £800–900 |
| Ohme Home Pro | Smart scheduling, some solar awareness | £650–750 |
| Wallbox Pulsar Plus | Solar integration via app | £550–650 |
| Zaptec Go 2 | Solar-ready, V2G capable | £900–1,000 |
The Zappi is the market leader for solar EV charging. Its Eco and Eco+ modes automatically adjust charging speed based on available solar power.
How Zappi's Solar Modes Work
Eco Mode:
Eco+ Mode:
Do You Need a Home Battery?
A home battery (like Tesla Powerwall) can store solar energy generated during the day for charging overnight. This is helpful if:
Cost: £4,000–10,000 for a home battery system
Alternative: Many EV owners simply schedule charging during solar hours when possible, or accept using some grid power overnight.
How Much Solar Do You Need?
Typical Solar Panel Output
| System Size | Annual Output (UK) | Miles of EV Driving |
|---|---|---|
| 3 kW | 2,500–3,000 kWh | 8,000–10,000 miles |
| 4 kW | 3,400–4,000 kWh | 11,000–13,000 miles |
| 5 kW | 4,200–5,000 kWh | 14,000–16,000 miles |
The average UK driver covers 7,000–8,000 miles per year, so even a modest 3kW system can theoretically provide all your EV charging needs.
The Reality
In practice, you won't capture all your solar generation for EV charging because:
Realistic expectation: A 4kW solar system might provide 50–70% of your EV charging needs annually, with the rest coming from the grid.
Cost Savings
Charging Cost Comparison
| Charging Source | Cost per kWh | Cost per Mile | Annual Cost (8,000 miles) |
|---|---|---|---|
| Solar (free) | £0 | £0 | £0 |
| Off-peak tariff | £0.07 | 2p | £160 |
| Standard grid | £0.24 | 7p | £560 |
| Public charging | £0.50 | 15p | £1,200 |
Return on Investment
Scenario: 4kW solar system + Zappi charger
Savings vs grid charging: ~£400/year on EV charging alone
Plus household electricity savings: ~£300–500/year
Payback period: 8–12 years (faster with rising energy costs)
If you're installing solar anyway, adding an EV charger significantly improves the economics by using more of your own generation.
Practical Considerations
When Is Your Car at Home?
Solar generation peaks between 10am and 3pm. If your car is at work during these hours, you'll miss the best charging window.
Solutions:
Seasonal Variation
UK solar generation varies dramatically:
| Season | Relative Output |
|---|---|
| Summer | 100% (peak) |
| Spring/Autumn | 50–60% |
| Winter | 15–25% |
In winter, you'll rely more heavily on grid power. In summer, you may generate more than you can use.
What About Cloudy Days?
Solar panels still generate on cloudy days, just at reduced capacity:
A Zappi in Eco mode handles this automatically — it uses whatever solar is available and tops up from the grid as needed.
Installation Requirements
For Solar Panels
For Solar-Compatible EV Charger
Do They Need to Be Installed Together?
No. You can:
Is It Worth It?
Yes, If:
Maybe Not, If:
Summary
| Question | Answer |
|---|---|
| Can you charge an EV from solar? | Yes |
| Do you need special equipment? | A solar-compatible charger helps (e.g., Zappi) |
| Can you go fully solar? | Partially — 50–70% is realistic |
| Is it cost-effective? | Yes, especially with rising energy costs |
| Do you need a battery? | Helpful but not essential |
Charging your EV from solar panels is one of the most satisfying aspects of EV ownership. You're literally driving on sunshine — and once the system is paid off, your fuel is free.
For most homeowners, the combination of a 4kW+ solar system and a Zappi charger offers the best balance of cost, convenience, and environmental benefit.