„I'm electric, I'm energised. [...] I am electric, the future is me,“ sings the
Electric locomotive Electra in the musical Starlight Express. These lines are particularly topical in view of electromobility. However, substations are urgently needed to ensure that the electricity gets to where it is needed in the future. This is because the electricity generated in wind farms and ground-mounted photovoltaic systems must be regularly transformed to a higher voltage level before it can be fed into the grid. As the substations are usually located close to the generation plants, similar planning and authorisation issues arise as with wind power or photovoltaic plants.

However, unlike generation plants, UWs require a building permit. As they are not classified in Annex 1 of the 4th Ordinance on Installations Requiring Authorisation as requiring authorisation under immission control legislation, they fulfil the requirements for structural installations. They are also not exempt from authorisation in the building regulations of the federal states. If a building permit is applied for, it must be granted if the project does not conflict with any „public law regulations“. This means that, in addition to building planning and building regulations, all public law regulations that are applicable to the specific project are relevant.

Firstly, the permissibility of a UW under planning law must be determined. If it is not to be erected in a commercial or industrial area defined by a development plan, but in an undeveloped outdoor area, the standard of assessment is based on Section 35 of the German Building Code. According to this, a project in an outdoor area is permitted on a privileged basis „if there are no public interests to the contrary, adequate development is ensured and if it [...] serves the public supply of electricity, gas, telecommunications services, heat and water, wastewater management or a local commercial operation.“

It is certain that a UW serves the public supply of electricity. Its permissibility in an outdoor area also requires it to be tied to a specific location. For UW, this can be justified by the required proximity to the feed-in point, as they cannot be erected at any location, but only at technically and grid-technically very narrowly defined locations due to their grid-bound nature. In addition, the Renewable Energy Sources Act (§ 8 EEG) stipulates that the most favourable grid connection point from a technical and economic point of view must be selected, i.e. generally the one that is the shortest distance as the crow flies from the location of the plant.

In addition, adequate access to the UW must be ensured. This means that - as with wind farms - there must be an appropriately wide and paved connection to the public road network for maintenance and rescue vehicles. If the road runs across private property, the crossing must be secured under public law by means of a construction easement. It is not uncommon for the local authority to own plots of land that are not formally dedicated to traffic. However, even in these cases, the development can be secured if the road plot is actually available to general traffic and the municipality is permanently legally prevented from prohibiting neighbouring traffic, for example due to the principle of equal treatment. This can be assumed in particular if neighbouring traffic has been regularly tolerated in the past or other facility operators have been permitted to use the road.

If the path needs to be developed beforehand, an offer of development should be made to the municipality. According to case law, municipalities must accept a reasonable offer from the developer to develop the property themselves in the case of privileged projects in outdoor areas - such as a UW. They must accept the development if no further uneconomical expenses are incurred after the development of the road and the acceptance of the offer is not unreasonable for other reasons, for example because the development of the road itself violates public interests.