Bidirectional charging: new Electricity Act provides better conditions

Bidirectional charging enables electric cars not only to draw power from the grid, but also to feed it back into the national grid or smaller networks such as households. The electric car thus becomes a mobile power bank that can help stabilise the grid in Switzerland.

Running from autumn 2022 to spring 2024, the pilot project saw. 50 fully electric Honda model ‘e’ cars integrated into Mobility’s regular car-sharing scheme. It was the first large-scale trial featuring bidirectional charging e-cars to be held in Switzerland. Among other things, the intention was to show how this technology can be used to stabilise the power grid and to investigate the business potential of bidirectional vehicles in a car sharing application in Switzerland. For the Mobility cooperative, the project was an opportunity to learn about developments and technologies in electromobility and the energy markets.

V stands for vehicle, the number 2 is pronounced to and the X means any recipient. In other words, the electricity flows from the electric vehicle to any location, e.g. into the grid or into the household’s electrical installation. The terms Vehicle-to-Grid and Vehicle-to-Home are derived from this arrangement.

Not only was the technical feasibility proven, but the bidirectional technology was also given a boost as well as a higher profile. The project demonstrated for the first time the possibility of combining multiple electric cars to create a virtual storage system and control the flow of energy in real time. V2X works at a technical level in a car sharing application. At the same time, it became clear that operating a fleet of bidirectional electric cars does not yet make sense as a business proposition for a car sharing company. Mobility is discontinuing its bidirectional charging technology for the time being.

The final report is due to be published on ARAMIS (the Federal Administration’s research database) in summer 2024. ARAMIS – the Federal Administration’s research database – homepage (admin.ch)

Before the project started, there was an assumption that a vehicle connected to a charge point would generate an average of one to two francs in flexibility revenue per day. We now know that income of up to 2’000 Swiss francs per year and vehicle could be generated, depending on market prices. However, because investment and operating costs are still too high, they exceed any potential income. As a result, running a business based on this concept is not (yet) viable.

The vehicles stopped feeding electricity back into the grid when they reached a set charge level. Mobility customer acceptance was high. The pilot phase saw our Honda e cars used by over 6,600 people, who covered in the region of 800’000 kilometres. Complaint-wise, almost none could be attributed to the V2X technology.

If V2G works in a demanding car sharing application, it goes without saying that it can work for any fleet operator.

Approved by the Swiss electorate on 9 June 2024, the Electricity Act improves the business case for bidirectional charging. It enables, for example, the reimbursement of double grid fees and the creation of a flexibility market for local distribution grid operators. However, it will take a few years for other factors to improve and for the technology to become widely accepted.

• The cost of bidirectional charge points must fall.
• Electric cars with bidirectional capability are few and far between, as the market hasn’t developed as quickly as hoped. Car makers need to bring more of these vehicles to the market, and at lower prices.
• Distribution grid operators need to boost the attraction of feeding electricity back into the grid.
• There needs to be an interoperable standard to facilitate fleet operations involving heterogeneous makes of cars and charge points.

Yes, because car makers are likely soon to introduce a global, interoperable standard. Different makes could then be charged and discharged at a single standardised charge point.

From Mobility’s point of view, V2X was a complete success, as we finally had answers to burning questions. Moreover, we were able to raise awareness of bidirectional charging technology, which helps to inform the public discourse in a positive way. The project also generated lot of data, offering us added value going forward. The findings from the project will be used to charge our electric fleet more intelligently. This is not only financially attractive, but also helps protect the batteries. At the same time, we’re pressing ahead with the switch to electric cars. Some 600 of Mobility’s 3’000 vehicles are already fully electric.