June 17, 2025, 3:40 am | Read time: 5 minutes
Operators of a photovoltaic system on their rooftop can benefit twice if they also use the electricity for their electric car charging station. How large should the solar system be at a minimum to make it worthwhile?
Electric mobility is on the rise and is being supported by the government. For owners of solar panels, an electric car is even more worthwhile, as they can “refuel” the vehicle directly at their own charging station. This article explains what to consider and how far you can drive with climate-friendly, self-produced electricity.
Table of Contents
- What are the advantages of combining solar panels and a charging station for an electric car?
- What costs should operators expect?
- How environmentally friendly is electric mobility?
- What should be considered during planning?
- What about charging other vehicles?
- What should be considered when operating multiple charging stations?
- What subsidies are available?
- How far can an electric car go with electricity from its own solar panels?
What are the advantages of combining solar panels and a charging station for an electric car?
“Photovoltaic systems, energy storage, and solar charging stations are the dream team of modern buildings,” explains a spokesperson from the German Solar Industry Association (BSW) in response to a myHOMEBOOK inquiry. The experts provide a practical example: A 40-square-meter photovoltaic system with a nominal output of seven kilowatts produces around 6,650 kilowatt-hours of solar power annually. This would theoretically cover the average electricity needs of a family of four—and also provide enough power for about 15,000 kilometers of range in an electric car.
Related: What homeowners need to know about electric car charging stations
What costs should operators expect?
“Photovoltaic systems have become increasingly affordable in recent years,” says the spokesperson. A small system for generating your own solar power is available for a few thousand euros. “You can produce solar power on your own roof for about ten cents per kilowatt-hour,” she continues. Planning, installation, commissioning, registration, and maintenance of the system are usually handled by the installation company.
How environmentally friendly is electric mobility?
Currently, there is still much to be done in this area, as the BSW spokesperson explains. “For electric mobility to truly serve climate protection, the expansion rate of solar energy must be significantly increased.” Without a multiplication of solar energy, the growing electricity demand due to the phase-out of nuclear and coal energy and the rise of electric mobility cannot be met in a climate-friendly manner.
Also interesting: Generating electricity with a solar panel on the balcony
What should be considered during planning?
If solar panel owners are considering powering their electric car with solar energy, they should plan thoroughly. “The metrological integration of the charging station within the customer system poses a challenge,” says the solar association spokesperson. “On one hand, it involves legal requirements for the measuring devices, and on the other, the clear distinction between self-consumption and delivery to third parties.”
What about charging other vehicles?
“If an electric vehicle is to be integrated into self-consumption directly from the PV system, it must be ensured that only company-owned vehicles are charged at the station,” explains the BSW spokesperson. If the wallbox also supplies other vehicles, a suitably designed measurement concept is needed to clearly distinguish delivery to third parties. “Otherwise, the privilege of reduced EEG surcharge on self-consumption for the entire customer system may be lost,” warns the expert.
What should be considered when operating multiple charging stations?
When operating multiple charging stations, special load management ensures that the permitted network capacity is not exceeded. Furthermore, unwanted power peaks must be avoided. “The energy management of the customer system must be coordinated with the load management so that priorities in the readiness of various vehicles can be maintained,” says the spokesperson. Specialist companies ensure that, in addition to installing the components—PV, storage, and wallbox from a single source—appropriate energy management is also provided.
What subsidies are available?
For the PV system, there is the EEG remuneration for the electricity fed into the grid. Additionally, the self-consumption of the cost-effectively generated electricity contributes to the economic viability of the system. “In some federal states, there are also special funding programs for home storage,” explains the spokesperson. Through the KfW, it is also possible to finance investments with a low-cost loan. There are also funding opportunities for the charging station itself. The spokesperson mentions the KfW grant 440 for charging stations at privately used parking spaces of residential buildings.
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How far can an electric car go with electricity from its own solar panels?
To answer this question, the spokesperson refers to a model calculation. The nominal size “kilowatt-peak” measures the output of a photovoltaic system. Accordingly, a sample PV system generates approximately 950 kWh per kilowatt-peak of installed capacity annually—depending on location and orientation. Incidentally, the kilowatt-peak can often be higher in other countries; this refers to what is achievable in Germany.
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Assuming an electric car consumes around 20 kWh/100 km, the electricity generation from a solar panel with just one kilowatt-peak is enough for approximately 4,750 km per year. Accordingly, a PV system with five kilowatt-peak can generate enough electricity to drive about 23,750 km annually without gasoline.