District Cooling in Munich
Overview
In past years, many (if not most) German cities did not have air-conditioning, however, due to the relatively hotter and longer summers in recent years, cities especially in southern Germany have been looking for district cooling technologies. Today, over 60 hotels, office buildings and department stores in Munich enjoy climate-friendly district cooling provided by SWM. The city is part of the Decarb City Pipes 2050 Project among 6 others across Europe.
Munich’s city utility, Stadtwerke Munchen (SWM), currently operates six geothermal plants, in addition to a district heating network of 900 km. SWM using its already present capabilities in geothermal heating, already has a number of projects underway to expand into district cooling in 2023. Beginning in the city’s Sendling district, the absorption chillers of the geothermal plant that create renewable cooling will soon be able to be circulated to parts of the city center. The network of pipelines will also supply inner-city clients in the Sending district with cooling. The 22 km-long grid has decreased electricity consumption by 70%.
Not only will the expansion of district cooling in Munich mean less downtown rooftops needing cooling units, but it will also improve the inner-city microclimate. While cooling units generate heat as they cool, this district cooling, using the canal as a natural-source coolant, does not emit heat waste as a byproduct.
Back in 2020, the project began by drilling 5 boring wells at Ramersdorf to feed the then-new district cooling system (~2.2 km long). Four of the five go 15-20 m deep and are used for extracting and then returning groundwater to the natural gravel layer. The last is an innovative horizontal filter well (drilled at 17 m deep), which is made up of 3 filter strings, each at a length of 40 m. Currently, SWM wells in Ramersdorf feed up to 120 litres of water per second into the district cooling network. The groundwater is circulated to the office buildings in Balanstrasse, where it is heated or cooled for many purposes before returning to the subterrain. Refrigeration machines and hybrid heating-cooling models have been fitted to produce heat and cold simultaneously. The capacity of the plants is 3 megawatts.
Summary
Depth of drilling: 15-20 m
Total length of wells: 22 km and growing
Units covered: equivalent to 100 building units
Public contribution: € 1 billion (from 2022-2035)