Integrated district-supply

What's the problem?

When solar systems are built, their electricity production is not always in line with consumption. Therefore, when electricity is used by the owner within the building or neighborhood, an unnecessarily large part of the electricity is often fed into the grid instead of being efficiently consumed locally. So far, innovative concepts that create sector coupling by integrating PV direct supply, storage and → electromobility have mainly been implemented in the form of pilot projects. The framework conditions for the supply of solar electricity to tenants* remain difficult and the billing is complex, the facilitations promised by the federal government through tenant*internal electricity laws are not yet sufficient to lead to a breakthrough of such projects.

What's the measure?

Photovoltaic systems on apartment buildings can be planned and implemented by third parties (e.g. energy cooperatives, public utilities or project developers) together with a tenant*internal electricity model, an electricity storage unit and charging points for electric cars. This maximises the use of electricity produced locally.

How can the implementation look like?

The example of the Heidelberg Energy Cooperative will be used to show what an integrated district supply can look like. HEG has installed photovoltaic systems with a total of 67 kWp (kilowatt peak output) on the roofs of two residential projects in Heidelberg's Südstadt. The solar power generated is primarily used directly by the people living there as tenants*. In addition, an electricity storage system ensures that surplus solar electricity is stored and its use can be postponed to times when demand exceeds generation. The charging station for electric cars also provides a buffer option and increases the proportion of solar power from the neighbourhood's own roof that is used within the neighbourhood. In addition to the electricity from the photovoltaic systems, the residents are offered other services: For example, the use of electric vehicels, transparent presentation of energy consumption and the possibility of participating financially in the local facilities through the energy cooperative.

How does this work against climate change?

The district-concept helps the housing projects to achieve a sustainable and decentralized power supply. In combination with the electrical storage and the battery of the electric car, a partially self-sufficient power supply is made possible, which is based entirely on renewable energies. In this way, the proportion of electricity from the grid, which currently always includes a proportion of climate-damaging electricity from fossil-atomic energy sources, is minimised.

Which other effects does the measure have?

The holistic and collaborative approach and the integrated planning by the cooperative in cooperation with the housing projects can save costs in acquisition and operation, but also strengthen the community. Through a broader range of services (charging station, e-car sharing) and the activating community elements (common grid connection, load wheel, and efficient appliances), → energy-turnaround becomes a motor for social interaction.

How quickly can the measure be implemented?

There already are examples for integrated district-supply. The knowledge and experience gathered there is transmitted in training courses, so that many other groups throughout Germany, can implement and immediately start it

Continuative literature, sources