Germany – Site-development work – WSP3_Tiefbau

The Stadtwerke Flensburg GmbH operates a combined heat and power plant at Batteriestraße 48 in 24939 Flensburg for the generation of electricity and district heating. A heat storage unit 2 was commissioned at this location in 2024. This serves as a buffer storage unit for the district heating supply of the city of Flensburg with a capacity of approx. 29,000 m3 of treated district heating water. Originally, this heat storage unit was integrated in parallel with heat storage unit 1, which has been in operation at the site of the combined heat and power plant for approximately 50 years. After the commissioning of heat storage unit 2, a condition assessment of heat storage unit 1 was carried out, which showed that refurbishment within economic conditions is not feasible. For this reason, heat storage unit 1 is currently being dismantled and will be replaced by the new heat storage unit 3 to be erected at the same location. Heat storage unit 3 is to be constructed as a non-pressurised heat storage unit with a steam cushion, identical in design to the heat storage unit 2 already in operation at the site. This means that a heat storage capacity of min. 900 MWh with a maximum storage temperature of 98°C and a return temperature of 65°C (Delta T 33°C) and, in addition, a maximum charging and discharging power of 90 MW is to be achieved. The anticipated dimensions of the storage unit are an internal diameter of approx. 42 m and a maximum fill height of approx. 21 m. Due to the parallel integration with heat storage unit 2, the same geodetic height of the maximum fill level must be achieved in both storage units. see also 00_Projektbeschreibung