Do you have solar panels on your roof and want to use more of your own electricity instead of feeding it back into the grid?
Bidirectional charging of electric vehicles is attracting growing interest. The concept seems particularly appealing: using your car’s battery to store the solar electricity generated during the day.
But before investing, it is important to consider one key question: is this really the most suitable solution for your home right now? In many cases, other solutions already enable you to effectively increase your solar self-consumption.
Using your electric car as a home battery: how does it work?
Bidriectional, or two-way charging, allows an electric vehicle not only to recharge itself, but also to feed electricity into the grid.
There are currently two main uses:
- vehicle-to-home (V2H): the car can power the home;
- vehicle-to-grid (V2G): electricity can be fed into the public grid.
In practical terms, this means that some of the solar power generated during the day could be temporarily stored in the vehicle’s battery and then used later when electricity demand increases.
However, in practice, several factors still limit its everyday use.
Not all vehicles and charging stations are compatible
Currently, bidirectional charging remains a technology still under development.
Not all electric vehicles support this feature, and not all charging stations are compatible. Certain solutions also depend on:
- the car manufacturer;
- the vehicle model;
- the type of charging station;
- or the home energy management system (HEMS) installed in the property
Future compatibility of equipment is not always guaranteed.
Before investing, it is therefore important to check:
- the compatibility between the vehicle and the charging station;
- the system’s potential for future upgrades.
Many homes already provide simpler and more effective solutions
When looking to increase your self-consumption of solar energy, bidirectional charging should not always be the first solution to consider.
In many cases, it is already possible to significantly optimise the use of solar electricity through:
- a smart charging point;
- an energy management system (HEMS);
- a home battery;
- or smart control of electrical equipment in the home, such as electric vehicle charging, certain household appliances or a heat pump.
These solutions are now more commonly available and often easier to integrate into an existing home.
The aim is to consume more electricity as it is being produced in order to reduce the amount of electricity drawn from the grid and thus lower your electricity bill.
Having the car at home changes everything
Two-way charging is often presented as an ideal solution for storing solar power generated during the day.
But for this system to work effectively, the vehicle needs to be parked at home precisely during daylight as electricity is being produced.
However, in many households:
- the car is used during the day;
- the vehicle is parked at work;
- or charging mainly takes place in the evening.
In this case, the vehicle’s battery is not available during periods where solar power is primarily being generated.
Conversely, certain situations may benefit more from this technology:
- working regularly from home;
- a second vehicle that is rarely used;
- a vehicle parked at home during the day.
Accordingly, it is essential to assess your actual usage and mobility habits before deciding on a solution.
To better understand which technologies can genuinely increase your solar self-consumption, it may be useful to compare different scenarios based on your home and your electricity consumption.
Klima-Agence’s solar simulator allows you to evaluate different configurations based on your home, your equipment and your consumption habits.
Which solution best suits your situation?
Every home has different requirements.
Before investing in a storage solution or charging infrastructure, it may be beneficial to ask yourself a few questions:
- Is your vehicle at home during the day?
- Do you mainly want to increase your self-consumption or reduce your energy costs?
- Would a home battery or an energy management system already meet your needs?
Klima-Agence advisors can help you analyse the solutions best suited to your situation with personalised, free and independent advice.