The most important facts at a glance:
- Promotion: approx. 150.000 €
- Time the promotion: 2015-2016
- Subject the Promotion: pro rata funding is provided for the adaptation of existing and the development of new software as well as for the installation of 4 photovoltaic systems, a lithium-ion storage system and the use of intelligent measurement technology.
- Technical data: 4 PV systems with a total of 233 kWp, 1 lithium-ion storage 30 kWh, 4 residential buildings with a total of 171 residential units
- Destination: Development and realization of tenant electricity projects, using renewable energy and smart metering technology, allowing differentiation by actual electricity use and generation based on 15-minute values.
How the tenant electricity model works
That's what every tenant wants: With electricity from decentralized generation, residents of an apartment building in Constance can significantly reduce their energy costs. The Constance public utility have developed a tenant electricity model that is seen as a milestone for the expansion of regional electricity generation, taking into account the digitalization of the energy industry. Stadtwerke supported the project with funding from its Green Electricity-certified green power product SeeEnergie Green ElectricityPlus.
In March 2016, the first tenant electricity project was commissioned together with the municipal housing association WOBAK in its building in Drechslerweg. In addition to 27 subsidized rental apartments, the apartment building houses a customer center of the savings bank and a police station. "For us, energy transition in the electricity sector means above all the expansion of highly efficient cogeneration and photovoltaics. With the tenant electricity model developed by our company, we have succeeded in successfully linking the promising business areas of energy supply contracting, telecommunications (fiber optics) and smart metering," reports Stadtwerke managing director Kuno Werner.
A combined heat and power unit (CHP) in the building generates both heat and electricity. In addition, there is a photovoltaic system with 23 kWp on the roof. The municipal utility sells the electricity from both plants directly to the tenants. Since the electricity does not have to be routed through the public grid, certain levies, surcharges, grid usage fees and electricity tax do not apply. "In general, tenant electricity models are characterized by lower energy prices and lower risks of price increases, as well as efficient and ecological energy provision," explains Gordon Appel, Head of Product Management at Stadtwerke.
The special feature of the tenant electricity model is the differentiation according to actual electricity use and electricity generation based on 15-minute values. "This makes it possible for tenants to benefit financially on the basis of actual electricity consumption and the different prices for direct electricity and residual electricity, and to adapt their consumption patterns to electricity generation," reports Appel. The model is currently being implemented in three other new WOBAK construction projects with around 140 residential units. There are also plans to extend it to existing buildings.