A 60–80 kWh battery on your driveway. Charge cheap, use when expensive, pair with solar. Your car is your arbitrage machine.
An electric car isn't just transport. If it supports Vehicle-to-Home (V2H) or Vehicle-to-Grid (V2G), it becomes the centrepiece of your home energy strategy.
Overnight on a cheap tariff like Octopus Go at 7p/kWh. Your car charges while you sleep.
Discharge into your home during peak hours when grid electricity costs 35–50p/kWh. The car powers your house.
Your solar panels generate free electricity during the day. Store it in your car battery. Use it at night.
| Component | Annual Benefit |
|---|---|
| EV salary sacrifice vs personal lease | £5,000 – 8,000 |
| Charging arbitrage (cheap → peak) | ~£1,000 |
| Solar self-consumption + EV storage | ~£1,045 |
| Avoided petrol costs (12,000 mi/yr) | ~£1,800 |
| Total | £8,845 – 11,845 |
A Tesla Powerwall is 13.5 kWh and costs £8–10k. Your EV battery is 60–80 kWh — 5x larger — and you're already paying for it via salary sacrifice. With V2H, you may not need a separate home battery at all.
0% VAT on residential solar until March 2027. Payback in 5–7 years. Everything after is pure profit.
| Tariff | Off-Peak | Peak | Best For |
|---|---|---|---|
| Octopus Go | 7p/kWh | ~24p | Simple EV charging |
| Octopus Intelligent Go | 7p/kWh | ~24p | Smart optimised charging |
| Octopus Flux | 3 rates + export | 28p export | Solar + battery |
| Octopus Agile | Varies | Varies | Advanced users (can go negative!) |