© Markus Schieder/Wien Energie
A unique district will be created in Vienna by 2027, in which climate-friendly heating and cooling will be provided with geothermal energy.
A construction site for a flagship urban planning energy project is located on the Aspanggründe site in Vienna’s 3rd district near St. Marx. This is from the Austrian Real Estate (ARE) together with the Vienna Energy implemented. Until 2027 should there one 11 hectares big real estate project to finish. It is described as a “perfect climate protection district”. Michael StreblManaging Director of Wien Energie.
The special thing about the project: There is a climate-friendly overall concept for the heating, cooling and power supply with geothermal probes and photovoltaic systems. According to ARE Managing Director Hans-Peter Weiss should 90 percent of the current and 75 percent of the heating output directly at the location of the “Village in the third” be generated.
Swiss cheese with 500 holes
For this reason, the construction site currently looks like “Swiss cheese”. There are deep holes everywhere in the area. Because about them 2,000 planned apartments, commercial areas, kindergartens and schools with sufficient energy, are currently being used on almost all of the 22 construction sites 500 geothermal probes with drills in 150 meters depth transported.
With the probes, the soil under the construction sites is used for heating in winter and for cooling in summer. “The geothermal probe can be imagined as a plastic pipe with a U-hackle,” explains Michaela Deutschthe site manager at Wien Energie, in a futurezone interview.
I visited the construction site. This is how it currently looks there:
Village in the third: site visit
9 Pictures
View slide show
© Picture: Barbara Wimmer
The green ones sticking out of the ground are the earth probes. They reach up to 150 meters deep
© Picture: Barbara Wimmer
That’s why the project is also called “Swiss cheese” internally – there are huge, dug pits all over the site
© Picture: Barbara Wimmer
Work is already underway in this pit
© Picture: Barbara Wimmer
© Picture: Barbara Wimmer
With this drilling machine, the geothermal probes are brought into the depths
© Picture: Barbara Wimmer
Here you can see how the black cables – these are the plastic tubes of the earth probes – are embedded in the ground by the construction workers with the drill
© Picture: Barbara Wimmer
The “Swiss cheese”: There are a total of 22 building plots on the 11-hectare site
© Picture: Barbara Wimmer
The fields that are close to the belt are currently being worked on. Over 100 of the 500 probes have already been put into the ground
© Picture: Barbara Wimmer
It cools in summer and heats in winter
“Water is slowly transported downwards through the plastic pipe, which means that the heat it contains can be released slowly in summer, and then cooled down again in the cycle and transported upwards,” explains the construction project manager. In the summer about 5 to 19 degrees cold water upwards, which is sent through a heat exchanger. It is then used in the buildings for underfloor cooling.
The system is able to increase the room temperature by up to 5 Grad to lower. “A good life” is what Jürgen Czernohorszky, Vienna City Councillor, calls it. “You can sleep through the seventh or eighth tropical night.” The individual probes are connected in the lower part of the building via cables to form a so-called “Anergienetz” tied together.
Because the ground at a depth of 150 meters has even more advantages: It is able to store the heat transported from the buildings in summer until winter. During the winter, this heat is extracted from the ground with water. This can be between 5 and 19 degrees to be warm. The water is then heated to a maximum of 37 degrees using a heat pump before it reaches the building using underfloor heating.
Anergienetz
This is the name of a heat distribution network that connects different energy sources and achieves the desired temperature level with the help of heat pumps. The heat pumps can be combined with photovoltaic systems. Possible sources of heat are waste heat, geothermal energy or solar thermal energy.
Village in the third
In addition to photovoltaic systems, a total of 500 geothermal probes will be installed in the new quarter in St. Marx. This is the largest geothermal probe field in Austria.
Photovoltaics on the roofs for the heat pumps
Thus, a large part of the energy is obtained from local resources. The energy required for the heat pump should come from the photovoltaic systems. They will be attached to the roof of each building. Strebl emphasizes that around 90 percent of the solar energy can be used on the site.
“That’s because we have offices, businesses and apartments that use electricity at different times,” says Strebl. However, the entire system is also connected to the district heating and electricity network.
To ensure that energy is used, distributed and stored optimally on site, the start-up Ampeers Energybrought on board. The spin-off from the Fraunhofer-Gesellschaft provides software for system operation management so that this energy project ultimately works.
