With solar panels on the roof, every kWh you charge into your own car is cheaper than a kWh you sell back to the grid for a fraction of the price. Your Smappee charging station can automatically charge on your surplus solar energy. Here is how to set it up, and how to avoid your car still being half empty in the evening.
What smart solar charging does
In Solar charging mode, your car only charges with the electricity your home does not use itself and that would otherwise go to the grid. When that surplus drops, the charging power drops with it. When there is too little, charging pauses.
What you used to export for very little, you now turn into kilometres. That way you get more return from your solar panels.
What you need
- A Smappee charging station with smart charging: EV Wall, EV One, EV Base or EV Dual. The Lite versions do not support this.
- A measurement of your grid connection. The Home versions have this built in; for other versions it runs through a Smappee Infinity or a P1 module on your digital meter.
- The Smappee app, linked to your installation
Not sure which version you have? The type is on the rating plate of the charging station and in the app under your charging station.
How to switch on solar charging
- Open your charging station settingsIn the Smappee app or the Smappee dashboard, go to the configuration of your charging station.
- Choose Solar charging as the charging modeFrom now on your car only charges on surplus solar energy.
- Set the grid supportWith the Grid support setting you decide how much power the charging station may draw from the grid so it can still charge. More explanation in the table below.
Why your car sometimes won’t start, even when the sun is shining
Technically, an electric car charges at a minimum of 6 amps per phase. That is a fixed limit from the charging standard, not a setting of the charging station. In practice this means:
If your car charges on three phases, there must be more than 4 kW of surplus before charging begins. On a cloudy day or with a smaller installation, that is rarely the case. With suitable charging stations on a three-phase connection (3×400 V), the system automatically switches between single-phase and three-phase charging, so you can also charge at less sunny moments.
Grid support: how much grid power is allowed?
| Grid support | Minimum solar surplus | Start on single-phase | Start on three-phase |
|---|---|---|---|
| 0 A | 6 A (100% solar) | 1.4 kW | 4.2 kW |
| 2 A | 4 A | ± 0.9 kW | ± 2.8 kW |
| 4 A | 2 A | ± 0.5 kW | ± 1.4 kW |
| 6 A | 0 A (100% grid) | immediately | immediately |
The higher the grid support, the more often your car charges, but the more power you draw from the grid. For most homes, 2 or 4 A is a good balance.
Does your car need to be full in the morning?
Charging on solar alone is ideal if your car is at home during the day. If you leave every morning, a combination works better: the Schedules mode lets you charge at fixed times, for example at night or during the cheapest hours on a dynamic contract, and tops up during the day with surplus solar. Also set a maximum grid capacity in the app, so charging never creates a new peak in your capacity tariff. More on that in our article on the capacity tariff and smart charging.
Do you also have a home battery? Then a few extra settings are needed to keep the battery and the charging station from working against each other. Read more in charging your car with a home battery.
Get more out of your solar panels
We review your installation and set up your charging station for your consumption and driving pattern.
- Check of your metering and charging station
- Setup of charging mode and grid support
- Advice on capacity tariff and dynamic contract
Based on Smappee’s documentation at the time of publication. Labels in the app may change with updates.