By Daniel Andersen
Daniel Andersen completed his Master in Energy Science and Technology. During the Master’s programme, he focused on the political, economical, and social aspects of the energy transition. He wrote his Master’s Thesis at the Group for Sustainability and Technology, supervised by Dr. Siobhan Powell. He’s now working as a consultant for electromobility and renewable energy at EBP.
In Switzerland, the potential of vehicle-to-grid (V2G) technology to integrate renewable electricity is huge, and by using batteries that already exist in electric vehicles, V2G is also more sustainable than producing new batteries for grid-scale storage. However, V2G technology is currently not profitable. In this blog post, I discuss how policy makers can overcome this financial barrier to utilize the full potential of storing renewable electricity with V2G.
To reach its climate and energy goals, Switzerland needs a significant expansion of renewable energy sources – mainly through solar photovoltaics (PV). However, higher solar PV capacities require more grid flexibility to ensure that the electricity supply always meets the demand, for example even when the sun is not shining. One possibility to provide this flexibility is through storage technologies such as batteries. Since the production of batteries is resource intensive and thus leads to adverse environmental impacts, we should aim to use existing rather than new batteries to provide the needed flexibility.
In the future, we will have many batteries installed in cars – probably more than two million already in 2035. The parked cars can be charged when the sun is shining and discharged when renewable electricity is needed. This bidirectional charging of electric vehicles is referred to as vehicle-to-grid or V2G.
Current state of V2G: high potential and political support, yet low adoption
Vehicle-to-grid has a huge potential in Switzerland. More and more car manufacturers are announcing or already produce bidirectional-capable electric vehicles. Furthermore, the battery of one fully charged Tesla Model Y, the most sold car in Switzerland in 2024, holds enough electricity to power an average Swiss single-family house with four residents for one week.
Figure 1: One bidirectional car can supply a family household with electricity for multiple days. Image by freepik
Policymakers are eager to use V2G to help bring more renewable energy into the system. The Swiss parliament has already made a decision that V2G operators won’t have to pay the full network fee when charging their batteries. Specifically, the energy that is stored and then sent back to the grid is exempt from this network fee. However, the exact implementation of this network rate exemption is currently in the consultation process. In this blog post, we analyse and discuss different implementations of this network rate exemption.
Policymakers should address V2G’s lack of profitability
Considering the potential of and the political support for V2G, why is this technology not being widely adopted? The reason is that it simply isn’t profitable. Firstly, V2G technology is very expensive, particularly the bidirectional charging stations, and secondly, only meager revenues, if any, are currently possible with V2G.
We analyzed how policy makers can make V2G profitable in order to integrate renewable electricity using car batteries. To answer this question, we assessed how the profit-oriented charging behavior of bidirectional cars reacts to a given time-of-use tariff for electricity. For this purpose, we used a linear-optimization model which uses the results from two other models (i.e. an agent-based model of electric vehicles and a Swiss electricity system model). Our results suggest three key recommendations for policymakers.
First, the recently approved network rate exemption is not enough to make Vehicle-to-Grid (V2G) technology profitable, regardless of the exact implementation of the network-rate exemption. Regarding the declining costs of bidirectional charging stations abroad, V2G could become profitable in the future. In Switzerland, the only available bidirectional charging station costs around 11’000.- CHF. However, similar products are now available in North America for around 4’000.- USD which leads to the assumption that future prices in Switzerland might fall as well. To support V2G now, policy makers could either subsidize V2G charging stations, as for example done in the Canton of Zurich, or increase the price spread between the high and the low electricity tariff. The latter does increase the potential for arbitrage since energy can be purchased at lower and sold at higher prices.
Second, policy makers should inform the population about how little battery degradation caused by V2G weighs against the other costs and revenues involved. A concern frequently raised regarding V2G is battery degradation. In contrast, our results suggest that battery degradation is only a very small cost component when doing V2G in cases with good V2G revenues, i.e. less than 2% of the total costs. Recent research has found that battery degradation is more a perceived fear of car owners rather than a technical challenge today.
Third, policymakers should not only increase the price difference between time-of-use tariffs but also adjust when low tariffs are available. Currently, many tariffs are high during the day and low at night, encouraging car charging at night and discharging during the day (see Figure 2, blue lines). However, with more solar energy, we need cars to charge when the sun is shining around noon and discharge that energy at night (see Figure 2, orange line). By shifting the low tariff period to midday, we can better integrate renewable electricity – some utilities in Switzerland already did that, for example the eniwa or EWS. We analysed a bidirectional charging station at a workplace under the current EV-tariff of EWZ and a new PV tariff. Our results indicate that one bidirectional charging station can help to integrate as much as 2 MWh of renewable electricity in 2050. This is enough to fulfill the energy demand of one person at home for about one year. This energy could otherwise not be taken up by the grid, either because the electricity in the grid cannot be transported from producer to consumer or because there is simply not enough demand for all the produced electricity. In these situations, the surplus of electricity is “wasted”, also called curtailed.
Figure 2: To integrate renewable electricity with V2G, the current time-of-use tariffs of electricity need to change. Instead of high prices during the day, as the EWZ tariff (blue), the new tariff (red) should have the low-price period around noon to incentivize charging then (a). These new tariffs lead to discharging before and charging around noon at a workplace charging station (b) which helps to integrate renewable electricity. Source: Andersen, D., & Powell, S. (2025). Policy and pricing tools to incentivize distributed electric vehicle-to-grid charging control. Energy Policy, 198, 114496. https://doi.org/10.1016/j.enpol.2025.114496
V2G technology has a large potential in Switzerland to integrate renewable electricity by using already existing batteries in cars. The largest hurdle today is the lack of profitability of V2G, mainly due to the high charging station costs. To utilize V2G by overcoming this hurdle, policymakers have already done the first step by passing a network-rate exemption, but more is needed: (i) V2G needs further support to become profitable, for example first by addressing the high charging station costs through direct subsidies and then by increasing the price spread of the electricity tariffs; and (ii) the time-of-use tariffs must be changed to low tariffs around noon.
Suggested citation: Daniel Andersen. “The profitability of Vehicle-to-Grid (V2G) and how this affects our use of renewable electricity”, Energy Blog @ ETH Zurich, ETH Zurich, May 14th, 2025, https://blogs.ethz.ch/energy/vehicle-to-grid/
Cover image: Image by user6702303 on Freepik
This blog post is based on Andersen & Powell (2025). Policy and pricing tools to incentivize distributed electric vehicle-to-grid charging control. Energy Policy, 198, 114496. https://doi.org/10.1016/j.enpol.2025.114496 s
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