Grid Tariffs and Bidirectional Charging – Pros and Cons of further exemptions for (mobile) storages

When charging electric vehicles from the public electricity grid, grid fees, taxes and levies need to be paid in addition to the cost of electricity supply for the energy consumed. This also applies when electric vehicles are used as (mobile) storage units in the form of bidirectional charging or more specifically vehicle-to-grid (V2G). In the Bidirectional Charging Management (BDL) research project, the field trial (in April 2022) showed that V2G generates revenues of 21 €, but 49 € in fees, taxes and levies are incurred over the same period [1].

V2G is generally not profitable today due to grid fees, taxes and levies

The example shows that V2G is generally not profitable today. However, the basic problem does not only affect mobile storage, but also all other storage technologies (e.g. pumped hydro storage, large-scale battery energy storage systems). The legislator has therefore defined discounts and exemptions of grid fees, taxes and levies for certain storage technologies and use cases. Mobile storage systems when used for V2G are also already exempt from certain levies.

Exemptions already exist for V2G

However, the grid fees make up the highest proportion of the additional charges for electricity consumption from the grid. While there are exemptions from grid fees for certain storage technologies, these do not yet apply to V2G. As a consequence, grid fees are being discussed as a barrier for the deployment of V2G. This discussion paper aims to contribute to structuring the debate on an exemption of grid fee for mobile storage (i.e., V2G) and to draw attention to aspects that have rarely been addressed. To this end, the following questions are analysed:

What is the regulatory framework regarding grid fees for stationary and mobile storage?
What arguments are put forward in favour of an exemption from grid fees?
What effect would an exemption from grid fees for mobile storage systems have?

Our conclusion

An extension of current exemptions of grid fees should not be a permanent solution: Instead, the regulatory authority should investigate how the high volumetric fees can be reduced by fundamentally reforming the grid tariff design. This could increase the attractiveness of the business case for V2G and other energy storage systems and overcome unequal treatment of different technologies in the regulatory framework.

Questions regarding practical feasibility, interactions with existing mechanisms and distributional effects have not been sufficiently answered for implementation: If the regulatory authority aims to exempt V2G from grid fees, a 1:1 extension of the provisions of Section 118 (6) Energy Industry Act (EnWG) appears difficult to implement in practice. Due to the bivalent or multivalent energy flows, the net billing scheme introduced by Section 21 Energy Financing Act (EnFG) would be more suitable for a potential exemption from grid fees if a viable metering concept can be developed.

In the case of a potential grid fee exemption, interactions with the provisions of Section 14a EnWG must be taken into account. The exemption for V2G use cases could be designed as an alternative to the defined modules under Section 14a EnWG in order not to counteract its effect. In addition, an exemption should only be granted if negative effects on the grid can be precluded to avoid a redistribution of grid costs at the expense of other consumers, especially lower-income households.

Discussion paper: Grid Tariffs and Bidirectional Charging

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Literature

[1] FfE (2023): BDL – Bidirektionales Lademanagement – Abschlussbericht der FfE, Bidirektionales Lademanagement – Abschlussbericht der FfE