Solar system for e-cars: charge at home with photovoltaic power

March 31, 2023

Estimated reading time: 5 minutes

You have your own solar system - great, then simply charge your e-car with solar power. Emission-free and easy on the wallet.

Solarpanele auf Hausdach

Charging an electric car with solar-powered electricity: How do I save money?

In light of feed-in tariffs declining and electricity costs rising, self-consumption of photovoltaic electricity is becoming increasingly important. Instead of feeding the electricity you’ve produced yourself into the grid for a low profit*, you should consume or temporarily store as much electricity as possible yourself.

The savings for each self-consumed kilowatt hour today is up to 26 ct., since you don’t have to purchase expensive electricity from the grid (electricity costs: up to 33 ct/kWh) or store your self-produced PV electricity temporarily in the power grid at high cost.

Flexible consumers play an important role in being able to use as much of your self-generated electricity as possible.
An electric car is particularly well suited to this purpose, since an electric vehicle is usually stationary for far longer (22 hours per day on average) than it is charging. This means your electric vehicle can be flexibly charged at a time that suits you, helping to ensure that as much of the PV electricity you generate yourself can be used.

* The feed-in tariff in Germany for new installations in July 2022 is 6.23 ct/kWh for installations generating up to 10 kWp, 6.06 ct/kWh for installations generating up to 40 kWp and 4.74 ct/kWh for installations generating up to 100 kWp.

Solar installation for charging your electric car: What are the advantages?

  1. Increasing PV self-consumption: In light of feed-in tariffs decreasing and electricity prices increasing, it is no longer economical to purely sell PV electricity. You should therefore use or temporarily store as much electricity as possible yourself.
  2. Cutting costs: Self-generated PV electricity gets your electric car moving at a cheap rate. You save 26 ct/kWh in costs compared to drawing electricity from the grid. 
  3. Protecting the environment: When you use electricity generated from renewable energy sources, greenhouse gas emissions can be reduced by up to 70 % over an electric vehicle’s total useful life.*

Strommasten am Straßenrand

Charging an electric car with solar-powered electricity: What do I need for that?

If you’d like to efficiently charge your electric car from your solar installation, you need a system consisting of three components

Additional meter

  • Installed behind the ESC meter; measures the surplus electricity. 
  • Passes this data on to the smart control system. 

Smart control system

  • Processes this data; uses the data to create the charging strategy. Also considers other factors (departure time, desired state of charge, etc.)
  • Passes the charging strategy on to the charging station.

Charging station

  • Implements the smart control system’s charging strategy and communicates with the vehicle. 

Your system doesn’t necessarily have to comprise three separate pieces of hardware. Some charging stations already have the smart control system integrated, enabling them to create their very own charging strategies. If your charging station does not have a smart control system, you can use a solar manager (also known as an “energy manager”). It processes the data from the auxiliary meter and develops the strategies for several consumers.

The schematic diagram below shows the PV installation’s potential consumers. In addition to the charging station, the home and electricity storage device can also be connected to the solar-powered electricity. In the future, the electric car will even be able to replace the domestic electricity storage device shown here. This technology is known as Vehicle-to-Home (V2H)

Supplying your electric car and private household with solar-powered electricity

Photovoltaikanlage an Haus im Garten


1. Installing a solar solution

Imagine this scenario: Your family lives in a single-family home and recently started driving a VW ID.3. The family members would preferably like to charge the vehicle using the photovoltaic installation mounted on the roof of your home, so you can make use of the solar-powered electricity the installation generates to the greatest extent possible and therefore be entirely emission-free on the road as often as possible. To use the solar-powered electricity, you have installed a solar solution consisting of an auxiliary meter and a smart control system.


2. Charging your EV with solar powered electricity

This solution will allow your family to supply an electricity storage device, your home and a charging station with electricity from the photovoltaic installation.
Having an appropriate usage profile (of both the electric car and auxiliary consumers) is critical if you are to consume as much of the generated PV electricity as possible themselves. Appropriate solutions, such as electricity storage devices, can help with temporarily storing excess PV electricity for subsequent use.
Based on the driving and charging profile, your family can cover 70 % of the electric car’s energy needs using solar-powered electricity.


3. Saving money and driving emission-free

Given the VW ID.3**’s average consumption (20 kWh/100 km) and annual mileage (10,000 km), it would require 2,000 kWh of energy annually. In this case, 1,400 kWh could be covered by self-generated solar-powered electricity, enabling emission-free travel over 7,000 km. Assuming a maximum cost saving of 27 ct/kWh, this results in an annual savings potential of approx. € 380.

**Reference vehicle: VW ID.3, consumption according to the General German Automobile Association: 19.3 kWh/100 km, rounded up for the sample calculation. Charging losses were not taken into account here.

Charging solutions for charging with solar-powered electricity

To find the right charging solution for charging with solar-powered electricity, it’s helpful to figure out which of the above items you already have, and which ones you still need. If you already have individual components at your disposal, you must take special care to ensure that new individual parts are compatible with your existing system.



Looking for a charging station that’s compatible with your existing system? We offer individual components that will complement your system perfectly.

FAQs: The key questions about charging with solar-powered electricity

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