The city of Aurich is breaking new ground in heating municipal buildings. So far it has been customary to use geothermal heat pumps or ambient air as heat source for district heating grids. However, the East Frisian town feeds waste heat from the effluent of a large dairy farm into its heating system. By means of external heat exchangers the 30 C water is used to supply a modern sports hall with heat and warm water.
In the dairy company on the outskirts of Aurich, 30 - 90 m³ of pre-treated waste water are generated per hour. The water is delivered to the treatment plant via a pressure line. An external heat exchanger can generate up to 1.5 MW of heat with a temperature of 12 - 25°C by means of cooling down the waste water. The low tempered water is then delivered to the sports hall through a district heating pipe, where it is heated to about 55 °C through a heat pump with a thermal output of 85 kW. The thus generated warm water is sufficient to meet the basic demand of the sports hall.
The heat potential of the waste water would even be sufficient to supply more buildings with heat or to undertake energetic measures such as the dehydration of sludge. Therefore, the concept allows achieving energy autonomy for the waste water treatment plant.
The concept of "cold district heating” offers heating solutions particularly suitable for the constantly high energy demand of urban infrastructure such as swimming pools and multi-purpose halls. The use of the renewable energy source 'waste heat' is an environmentally friendly alternative to conventional technologies with good prospects to be economically operated.


Project Operation
Auricher Stadtentwässerung
Fischteichweg 10
26603 Aurich
Tel.: 04941-12 1500
Fax.: 04941-12 55 1500
schulz@stadt.aurich.de
www.aurich.de

ECO.S Energieconsulting Stodtmeister
Morgensternstraße 24
12207 Berlin
Telefon 030 - 25 930 960
energie@eco-s.net

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