In practice no approvals for GMPV due to building legislation in Switzerland

The federal spatial planning procedure states that buildings/construction outside the building zone (Bauzone) are only permitted if they are site-specific (Standort-gebunden)

So far, GMPVs are not regarded as site-specific as these PV installations could be built either on the ground or on rooftops.

GMPVs are practically not built within the building zone, as the space is either reserved for houses or prices are too high due to the competition with the housing market and are economically not feasible.

This is primarily a problem of the Raumplanungsgesetz (spatial planning law). Sites for GMPV are only permitted if specific sites outside the building zone have been entered into the Richtplan (site structure plan) in beforehand. An entrance into the site structure plan is only within the authority of the canton and takes several years. In practice, entrances in the site structure plan are not happening as there is no consensus on whether GMPV is needed in Switzerland.    

A revision of the Spatial Planning Ordinance (Raumplanungsverordnung) is currently in progress and is expected to come into effect 1. Juli 2022. The revision also entails clauses to enable approval processes for PV mounted on existing infrastructure.