In north-west Germany, the town of Bremen is crossed by the picturesque river Weser. Now this historic waterway is providing heating for a district network thanks to a large heat pump.<\/p>\n\n\n\n
The 5 MW pump extracts thermal energy from the river, even at temperatures as low as 0.1\u00b0C. <\/p>\n\n\n\n
It\u2019s a pretty innovative 5 MW heat pump concept that uses river water as heat source. Also, there is a surface cooling water reservoir functioning as another heat source in the summer that is being used as a public ice rink in the winter.<\/p>\n\n\n\n
The system, developed by Stadt Energy Speicher GmbH, uses a vacuum evaporation process developed in collaboration with ILK Dresden. The resulting thermal energy is used to power the large heat pump, while the by-product \u2013 a slush-like ice mixture \u2013 is returned to the river in winter. <\/p>\n\n\n\n
In summer, the vacuum-based liquid ice generator, in combination with a 150 m\u00b3 slush ice tank, functions as a cold storage system, enabling buildings to be cooled using electricity from photovoltaic (PV) systems.
The system also includes a surface cooling water reservoir, which in summer serves as an additional heat source for the heat pump. <\/p>\n\n\n\n
In winter, the surface is frozen and becomes a public ice rink. The waste heat produced during the ice-making process is fed into the heating network via the return line.
Flexible use of electricity and load shifting are enabled via a 600 m\u00b3 high-capacity thermal storage tank, a power-to-heat module (1 MW electric), and an intelligent control system.
The whole thing covers 63,000 m\u00b2 of residential and 55,000 m\u00b2 of commercial floor area.<\/p>\n\n\n\n