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Geothermal heat to also fuel district cooling network in Munich, Germany

Drilling rig on site at HKW Süd, Munich/ Germany (source: SWM)
Alexander Richter 18 Apr 2020

Expanding its district cooling capacity and services, the city utility of Munich, SWM is also going to utilise geothermal energy to generate cooling using absorption chillers at a new geothermal heat plant being built.

The city utility of Munich, Stadtwerke Muenchen (SWM) is working on an extension of its district cooling networks. So far the city has three cooling centers, but with increasing demand, SWM is now investing EUR 80 million (around USD 88 million) in construction for both generation and necessary network connections.

“We generate the district cooling centrally and distribute it to the customers via pipes. Renewable energies make a significant contribution to refrigeration. This significantly reduces the CO2 burden. In addition, individual air conditioning systems in the buildings and their waste heat on site. The district cooling counteracts the summer heat bell over the city center and the overall warming of Munich. ”, so Helge-Uve Braun, Technical Director at SWM.

District cooling is in demand

Today, SWM already provides climate-friendly district cooling to more than 60 hotels, office buildings and department stores in the city. An additional connection of about 60 properties  through its M district cooling network, is already in planning stages.  The current inner city network is about 12 kilometers long, but keeps growing every year.

So far the the cooling capacity is fuelled by three district cooling centers, utilising the natural energy of underground water streams, fully in the winter, yet supported by compression chillers in the summer time. Utilising the naturally cold water stream allows energy savings compared to traditional cooling technology by around 70 percent.

At its Heizkraftwerk Sued plant, SWM is producing district heating in a combined heat and power generation set up.

Helge-Uve Braun: “Our natural gas-powered turbines generate electricity in the southern CHP plant, and the hot waste heat is converted into district heating. Up to 90 percent of the energy from natural gas is used in this way – CHP is one of the most effective and climate-friendly conventional production methods. In addition SWM are currently modernizing the turbine systems, which means an even better energy yield is possible. ”

For the 2021 heating season, heat generation will be supported by Germany’s largest geothermal plant to date, being built by SWM at the moment. We reported on the drilling for the project before. The plant will provide clean geothermal district heating to more than 80,000 residents of the city of Munich.

But the existing heat from geothermal energy and cogeneration will also used for district cooling. In
absorption chillers the existing heat will also be used for district cooling and via the newly created transport line to customers along the route and downtown Munich.

The plan is to carry cold air from a geothermal

Source: SWM press release (pdf), further details (Fernkaelte)