EV Charging Calculator

How Much Does It Cost to Charge an EV at Home?

Most EV owners charge at home — and home charging is typically 3–5× cheaper than the equivalent petrol or gas cost. The exact figure depends on your electricity rate, how far you drive, and your car's efficiency. A typical EV uses 15–20 kWh/100 km (24–32 kWh/100 miles). At home electricity rates, that works out to roughly a third to a fifth of what you'd spend on fuel for an equivalent petrol/gas car.

Home vs Public Charging Costs

Not all charging is equal. Here's how the main options compare (approximate ranges across markets):

• Home (off-peak overnight): The cheapest option for regular charging. Off-peak rates vary by market — around £0.07–£0.12/kWh in the UK, $0.08–$0.15/kWh in Australia, $0.06–$0.12/kWh in the US, and R1.00–R1.80/kWh in South Africa.
• Home (solar — midday): Effectively free if your solar is generating more than you're using. The best option if you can charge during the day.
• Home (standard rate): Still much cheaper than fuel. Standard rates range from £0.24–£0.30/kWh (UK), $0.22–$0.35/kWh (AU/US), to R2.50–R4.00/kWh (ZA) depending on your plan.
• Public AC (destination charging): Convenient but more expensive than home charging.
• Public DC fast charging: Typically 2–3× the home rate. Use for long trips, not daily charging.

The bottom line: most EV drivers do 80–90% of their charging at home, making the home rate the one that matters most for annual running costs.

Charge Your EV From Solar — Effectively Free

If you have rooftop solar, you can charge your EV at near-zero cost by shifting your charging to midday when your panels are generating more than your home is using. Here's why this is so powerful:

• Excess solar is otherwise wasted or earns a tiny export rate. In most markets, feed-in or export tariffs are a fraction of what you pay to buy electricity. By diverting that surplus into your EV instead, you're displacing grid electricity at full retail rate — a much better deal than exporting.
• A typical 5–8 kW solar system can generate 20–35 kWh on a sunny day. If your home uses 10–15 kWh during the day, the remaining surplus is enough to add 30–130 km (20–80 miles) of EV range — for free.
• Smart EV chargers automate this. Chargers like the Zappi (UK/AU), Fronius Wattpilot, or solar-aware home energy systems detect surplus solar and ramp up EV charging rate accordingly.

Solar + EV + Battery: The Full Picture

The ultimate setup is solar panels, a home battery, and an EV working together. During the day, solar charges both the home battery and the EV. In the evening, the home battery covers household demand. Overnight, the EV can top up from the battery or from cheap off-peak grid power. And on days with very high wholesale prices, your EV could even export power back to the grid via V2G, earning revenue that offsets your charging costs entirely. Use the Photonik app to model this complete system with your real tariffs and solar profile.

Can V2G Offset Your EV Charging Costs?

Vehicle-to-Grid (V2G) takes the EV one step further: your car's battery can export power back to the grid during rare, extreme wholesale price spikes — earning significant revenue from just a handful of events per year. In markets with volatile wholesale pricing (Australia, California, UK), a single V2G event during a price spike can earn the equivalent of a week's charging costs.

V2G requires a bidirectional-capable EV (Nissan Leaf, Mitsubishi Outlander PHEV, BYD Atto 3, and select others) and a compatible V2G charger. It's still emerging technology in most markets, but adoption is accelerating — particularly in the UK and Australia where VPP and demand-response programs are already established.

Frequently Asked Questions