The municipality of Warthausen is located in South West Germany in the federal state of Baden Württemberg, close to the Switzerland and Austria. In 2013, a grid-connected photovoltaic system has been installed on several roofs of the local primary school. In 2017 there were 181 pupils attending the primary school The PV system is owned and run by the local energy cooperative called Energiegenossenschaft Riss. In order to have the system installed on the local school the energy cooperative is leasing the roof off the municipality.
The energy cooperative has currently about 260 members who have all invested in various renewable energy projects in the area. The energy cooperative is open for everyone and operates as a grassroots democracy. This means that every person who owns shares in the cooperative has got a voting right. The reason for people to join the cooperative is to earn money through renewable energy projects and at the same time it allows them to actively support their local energy transition and contribute to the overall climate change goals. Since some of the cooperatives members are also representatives of the municipality their cooperation with the municipality is very close.
The grid connected PV system is set up in a way that some of the electricity that is being generated is consumed directly by the school itself and the surplus energy gets fed into the grid, receiving a feed-in tariff. The ratio of self-consumption and feeding into the grid is about 25-35% to 75-65%. In 2016, about 37.27% of the annual electricity consumption of the school was covered by the PV system, whilst the annual electricity consumption of the school was 59.790 kWh