Image: The Mobility HouseThe Mobility House (TMH) has long been recognised as one of the pioneers of bidirectional charging and its sub-discipline, Vehicle-to-Grid (V2G) – the process of feeding electricity from electric vehicle batteries back into the public grid. This is something that the electromobility community has been aware for some time. As early as 2024, TMH manager Marcus Fendt discussed in our podcast (audio in German) which regulatory adjustments are still needed for V2G to achieve widespread adoption in Germany – and how V2G could enable cost-free electric driving.The Munich-based company has now taken a significant step towards realising this vision. Herbert Diess, Chairman of the Supervisory Board and former CEO of the Volkswagen Group (audio in German), recently announced an offer of free charging electricity. The offer, which is tied to TMH’s own V2G electricity tariff for private customers, is set to launch this quarter for the all-electric Renault 5. This will then be followed by the new Mercedes-Benz electric models, the CLA and GLC, later in the year.In parallel, TMH shared on LinkedIn that practical experience with the world’s first V2G product for end customers, launched in 2024 in collaboration with the Renault Group in France, demonstrates the following: if an electric car is connected and available for bidirectional charging for an average of 14 hours per day, the charging costs for a driving distance of 10,000 kilometres can practically be reduced to zero.The potential for V2G to enable cost-free electric driving (excluding vehicle purchase costs) lies in the constantly fluctuating demand for electricity. A V2G-capable electric vehicle can store electricity in its traction battery when there is, for example, a surplus of solar and wind power or when demand is very low at night. Conversely, the vehicle can feed electricity back into the grid via a special V2G-capable wallbox when demand is particularly high, helping to absorb peak loads and stabilise the grid. Prices fluctuate significantly during these periods, and TMH can capitalise on the arbitrage effect – the price difference between buying and selling electricity. TMH plans to pass these savings on to its customers in the form of free electricity.“We are still small. But if our business model works – and the chances are high – electric cars will be able to drive for free,” says Herbert Diess, the prominent figurehead of TMH and former CEO of the Volkswagen Group. The business model gains attractiveness from the fact that, since the turn of the year in Germany, the batteries of electric vehicles are treated the same as stationary battery storage systems – eliminating the double grid fee.E.ON and BMW to also offer V2GE.ON has recently begun offering a special V2G electricity tariff for the new BMW iX3. While free charging is not explicitly mentioned, the costs for driving 12,000 to 14,000km can be offset through a bonus account. Customers receive €0.24 credited to their bonus account for every hour the car is connected to the special V2G charging station – regardless of whether electricity is being charged or discharged. The amount is capped at €60 euros per month or €720 euros per year, equivalent to around 250 ‘connection hours’ per month. For feeding electricity back into the grid, customers receive even more: every kilowatt-hour actually discharged is compensated with €0.40.Another interesting package has been introduced by Octopus Energy and BYD in the UK: for a monthly subscription fee of £299, customers receive a BYD vehicle, a V2G wallbox, and electricity – the latter, however, only if the vehicle is connected to the wallbox for at least 20 times a month for 12 hours at a time.faz.net (DE), linkedin.com (France practical experience)