The Zimel self-consumption association (CSC Zimel) has been under construction on the Unterägeri municipality’sbuilding lot since spring 2020. The site currently consists of 12 buildings with 101 apartments. Five additional apartment buildings with a total of 48 apartments are currently under construction. The site’s energy supply is sourced as locally as possible. In addition to solar power from the photovoltaic (PV) system and drinking water, heat is also provided by the local municipality.

The origins of the Unterägeri Corporation date back to the Middle Ages and essentially involve the administration of the common lands of the municipality of Unterägeri. Today, about 8,500 people live in Unterägeri, and there is a high demand for housing. Since the Unterägeri Corporation owns large tracts of building land in Zimel, it decided to build new housing there.

A key element of the municipality is the sustainable use of local resources. “We are convinced that, as a municipality, we can make a unique contribution to the energy transition in Unterägeri. We have the long-term perspective and the financial resources to make sustainable investments. It is important for us as a municipality to set a good example,” says Thomas Hess, municipal secretary of the Unterägeri municipality.

Generating its own solar power for the Zimel site was the logical next step. As a first step, the Zimel energy concept was presented at the town council meeting in September 2020. The concept focused on three key points: the merger to meet its own energy needs (CSC), the purchase of heat from the heating plant, and the size of the major customer.

First, the corporation plans, finances, and operates the solar power installations on all roof areas. Although the apartments are sold, the right to use the roof areas remains with the corporation. Instead of feeding the solar power into the grid, the corporation sells the electricity to its residents. A co CSC , is formed for this purpose. Second, heat will be supplied by the Rain heating center, which is currently under construction. In the central heating plant, water is heated using wood chips from the corporation’s forest. Third, the size of the development will allow it to be classified as a major customer in the future. This is because the Zimel area will reach an annual consumption of over 100,000 kWh and will be able to freely choose its electricity supplier. This will further reduce the price of electricity and, consequently, residents’ electricity costs.

The second step involved the planning and actual implementation of the project. This work was carried out by a local electrician, Iten-Arnold Elektro AG. Marc Iten, Managing Director, and Pascal Terreni, Project Manager at Iten-Arnold Elektro AG, were in charge.

They had already implemented self-consumption associations (CSC) before, but not yet on a scale of this size. Iten says, “ZEVs are a great solution. It simply always requires someone who is decisive, has authority over the energy consumers, and has the financial resources to make the investments.” According to Iten, institutional investors such as pension funds, corporations, or housing cooperatives are ideally positioned to implement ZEVs, but are still doing far too little. This is also because negotiating with the client requires clarification. According to Hess, negotiating with the building owners was the biggest challenge. Some building leaseholders were skeptical about the PV system and the entire energy concept. However, the housing cooperative provided the necessary information and was ultimately able to implement the concept as planned. Construction work on the first phase of the Zimel development plan got off to a successful start in spring 2020 with the Cluster Mitte. The first buildings in the Cluster Mitte were ready for tenants to move into in spring 2022.

Today, the first buildings in the Zimel development receive electricity, heat, and even water from the corporation—and thus from a local source.