Setup
No electrician. If you can clip a cable and open an app, you can do this.
- Step 1
Check your car supports bidirectional charging (V2H or V2G). Most new EVs do; the app has a list.
- Step 2
Have a bidirectional charger fitted, or plug the gateway into the one you already have.
- Step 3
Set a reserve, the charge you always want left in the car. 60% keeps plenty of range.
- Step 4
Set a floor and tell the app your usual departure time so it never sells right before you leave.
An EV battery is three to six times the size of a home battery, and it spends most of its life parked. Selling from it is the same idea as a home battery: charge when power is cheap, sell when it is dear.
The reserve is the whole trick
You set a minimum charge and the car never goes below it. Everything above that line is available to sell during the peak. Most owners set 60% and forget about it.
Wear
Selling a few kWh in the afternoon peak is a fraction of a day’s driving. Manufacturers that support bidirectional charging cover it under warranty, and the app caps daily discharge well below what a commute uses.