Many residential developments for thousands of people were built on the outskirts of large cities in Germany in the 1970s. These included the district of Mümmelmannsberg in the east of Hamburg. To supply heat, a district heating grid about 15 kilometers long was also built at that time, which supplies 7100 households from a central combined heat and power plant.
Modernization of the combined heat and power plant during ongoing operation
After a combined heat and power unit (CHP) was added to original hot-water boilers in 1998, extensive renovation of the entire plant started in 2016 with an investment of around ten million euros: five outdated boilers were replaced by three high-performance Vitomax LW low-pressure hot-water boilers with a total output of 32 MW during ongoing operation. The old CHP was replaced by two new units. URBANA Energiedienste GmbH executed the project. For more than 40 years, the company has been providing the complete heat supply on behalf of the municipal housing company SAGA GWG in Mümmelmannsberg.
16000 tons of carbon dioxide are avoided
Parallel to the installation of the new boiler system, the modernization of 320 house transfer stations was also completed – saving around 16000 tons of harmful CO2 per year.
The Vitomax boilers are equipped with flue gas heat exchangers (economizers) for utilization of condensing technology for efficient operation. Together with the two CHPs, 90 GWh of heat and 40 GWh of electricity are produced per year.
Affordable heating costs with new heating technology
The new solution is easy on the residents’ wallets. In addition to the CO2 savings, the district heating price was reduced to 6.7 cents per kilowatt hour. For a three-room apartment in Mümmelmannsberg, this means less than 50 euros per month. The low-cost supply also benefits around 60 public and church institutions and commercial enterprises in the large development, which are also connected to the district heating grid.