The operators of plants for the production of electrical energy, for example photovoltaic plants, may not only consume the energy generated at the place of production themselves, but may also sell it – in whole or in part – for consumption at the place of production. Both circumstances are considered self-consumption, which can be economically advantageous under the right conditions.
A merger for own consumption (ZEV) can be taken into consideration if the production output of the plant is significant in relation to the connected load (at least 10% of the connected load). In this case, only one measuring point is used for measuring, as the distribution system operator must treat the parties involved as individual end consumers. Such an association may exist between several landowners and/or between a landowner and his tenants (or leaseholders). The ZEV is of particular interest for the owners of industrial, commercial and residential premises. It enables them to increase the return on their energy generation plant, due to the higher rate of self-consumption associated with the ZEV. In addition – provided that the ZEV has an annual consumption of at least 100,000 kWh – all parties involved can purchase energy at more favourable conditions within the parameters defined for grid access, for example if the energy requirement is not covered by the energy generation plant or not covered at all times during the day (keyword: exploitation of the pooling potential).
If the ZEV is also to be made available to tenants, before its introduction – especially in the case of pre-existing tenancies – not only the energy law provisions but also numerous tenancy law provisions must be taken into account. For example, for value-adding investments and energy improvements, an appropriate rate of interest, amortisation and maintenance of the investment must not be exceeded. Furthermore, it must be ensured that when adjusting the rent, for additional electricity costs, the forms approved by the canton are always used and abusive rent adjustments are avoided. Such adjustments may occur in particular if the general electricity was previously included in the net rent and now, after the introduction of the ZEV, appears in the service charges without the net rent being reduced accordingly.
While existing tenants may choose not to participate in the ZEV and continue to purchase electricity from the distribution system operator, this choice is not available to new tenants. Once the merger has taken place, all tenants are obliged to purchase electricity from the locally produced energy, unless the individual tenant is entitled to grid access (and makes use of the change of energy supplier) or the landlord fails to meet its obligations to provide adequate electricity.
The use of self-generated energy for self-consumption as well as participation in a ZEV can yield important – not least economic – advantages for energy producers (and for the users on site). However, it is essential to be aware of the conditions under which these possibilities are available. It should also not be overlooked that the exhaustion of these options under energy law can bring with it new obligations, especially under tenancy law.