As part of the EU project SMARTER TOGETHER smart solutions for a city district are developed, which also affect the infrastructure. One focus concerns energy supply, such as the use of waste heat or the integration of renewable energies. Only a part of the planned projects in this area could be realized despite high efforts. Nonetheless, promising concepts have been developed and important insights gained that will enable their realization in the future.
The waste heat of a data centre in the project area should be fed into the district heating network. Since implementation was not possible, another data centre near the project area was considered. Detailed concepts were developed for both cases, but they could not be realized. On the one hand, the restrictions of the network for the year-round absorption of waste heat lead to high costs. On the other hand, the operators of the data centres do not give a sufficiently long location guarantee. However, the results can be used for further future projects. Also, the return line of the district heating in a new building could not be realized due to the already advanced planning of the construction. It would be necessary to integrate a low-temperature floor heating system when planning the building. The feed-in of solar thermal energy on the roof of the school into the district heating is going to be realized. The densification of district heating in already connected buildings has also taken place. The findings will be used for replication, especially for the residential buildings owned by the city. From all these insights and experiences, the future of district heating is defined. This includes densification, feeding in renewable energy sources and waste heat as well as the use of the return for heat supply.
In the course of the project, a successful implementation of PV projects was achieved. Two of the refurbishment projects as well as the new logistics centre of the beverage company Ottakringer are using solar energy to generate electricity. In addition, the project area has begun to switch public street lighting to high-efficiency LED. In the forecourt of the school so-called solar benches were installed to raise awareness of renewable energy. This is a street furniture that has integrated PV with batteries and provides a port for charging mobile phones. However, there were challenges in terms of responsibilities and liability issues, as well as in procurement, construction and ongoing support.
The Energy Planning Department of the City of Vienna carried out an investigation of the energy-relevant data of the area - a so-called energy assessment (“Gebietsscreening”). The information generated from this, such as the energy demand or the potential of renewable energy sources, generated strong interest in the issue. This showed the importance of an appealing presentation of energy-related data as a communication tool. Building on this, the City of Vienna was able to develop an improved energy data model. Thanks to the individual implementation projects, whose linkage was hardly possible, important insights into the control of the energy supply of the building stock and urban development could be gained. The need for integrative solutions for refurbishments that extend beyond the building and that also consider a possible switch in energy supply, was strongly carried out. The knowledge generated is used in ongoing processes for the implementation of energy planning in the City of Vienna. The aim is to coordinate spatially and temporally the efficient use of the pipe infrastructure (district heating and gas) by avoiding double supply as well as the integration of renewable energy sources both in new buildings and in existing buildings. Ultimately, this is a major contribution to the decarbonization of energy supply.