Driving an electric car is cheap, but can it be free? Yes, if you connect your home charging station to your own photovoltaic system. This is the key to maximum energy independence and the lowest EV operating costs. Check out how an intelligent wallbox manages surplus solar energy to charge your car for “pennies”.
Photovoltaics and an electric car – the perfect match
A PV system produces the most electricity during the day when the sun is shining brightest. However, household members are often at work during these hours, and the produced energy (surplus) goes into the power grid. Sending electricity to the grid (in a net-billing system) is less profitable than using it immediately (self-consumption).
An electric car connected to a wallbox during the day is an ideal “energy storage”. Instead of giving away electricity for next to nothing, you “refuel” it directly into your car’s battery.
Charging a car from photovoltaics?
The key to effectively combining PV and EV is not a regular socket, but an intelligent charging station. Wallboxes equipped with advanced communication systems can effectively cooperate with the energy meter in your home.
Dynamic power management (Load Balancing) in practice
Thanks to the dynamic power management function, the wallbox continuously monitors how much electricity your panels are producing and how much home appliances (fridge, heat pumps, washing machine) are consuming.
- When the sun is shining brightly: The wallbox automatically increases the car’s charging power, using all available surplus energy from the PV.
- When you turn on the kettle: The wallbox instantly reduces the charging power so as not to overload the home installation and avoid drawing expensive electricity from the grid.
Thanks to this, you can be sure that the car is charging mainly with free energy from the sun.
Charging modes adapted to your photovoltaics
In the mobile app, you can choose the operating modes that best suit your PV system:
- ECO Mode (Solar Only): The charger starts only when the photovoltaic system produces a surplus of energy. The car charges slower, but 100% for free.
- MIX Mode (Solar + Grid): Ideal when you need to charge your car faster. The wallbox uses all the free energy from the sun and draws the missing power from the grid (e.g., during a cheaper night tariff).
Does charging from photovoltaics damage the battery?
This is a common myth. In reality, charging a car with alternating current (AC) at variable power (depending on the sun) is very healthy for the battery. BMS (Battery Management System) systems in modern EVs are designed to handle such fluctuations. Moreover, charging at lower power over several hours generates less heat than fast DC charging, which drastically slows down cell degradation.
How to connect a wallbox to photovoltaics in 3 simple steps?
Step 1: Choosing an intelligent charger with communication
A regular “on/off” wallbox doesn’t know if the sun is shining. You need a device that has communication protocols (e.g., OCPP protocol or dedicated signal inputs) that allow it to work with the rest of the house.
Step 2: Installing current transformers (CT) or a smart meter
For the wallbox to know that you have an energy surplus, it must receive information from the building’s connection point to the grid.
- Small clamps (transformers) are installed on the cables powering the house or an additional Smart Meter.
- They “tell” the charger: “Hey, the house is using 2 kW, the panels are producing 6 kW, we have 4 kW of free electricity – charge the car!”.
Step 3: Configuring the Solar mode in the app
The final stage is setting priorities in the mobile app.
- You choose whether you want to charge the car only with surpluses (cheapest, but slower) or allow drawing from the grid when the sun goes behind a cloud.
- After this configuration, the system becomes maintenance-free – you plug in the cable, and the sun does the rest.
Invest in an intelligent solution
Combining a photovoltaic system with an intelligent wallbox is an investment that pays off the fastest. You gain the comfort of charging at home, maximum self-consumption of free electricity, and the certainty that your car is always ready to go – at the lowest possible cost.