Fjärrvärme från Slammertorps värmepumpar

Slammertorp's heat pumps in Kallhäll, Järfälla municipality were built in 1984 and commissioned in 1985. Until 2019, the plant was the base distributor for Järfälla district heating network. In recent years, the plant has been changed to a cutting-edge plant that annually produces about 100-150 GWh of district heating. The plant consists of two seawater heat pumps with a power of about 25 MW each. The heat pumps extract heat from lake water in nearby Lake Mälaren and can produce maximum heat output as long as the sea water temperature is above 2 degrees Celsius. The output temperature on the district heating side is between 75-82 degrees Celsius depending on the heating needs of the customers.

The district heating network in Järfälla began construction in the 1970s, but most of the network is from the 1980s. Extensive expansion is ongoing, especially in areas of development. PEH (high- density polyethylene) is the completely dominant conduction type but short distances of hole pipe culvert are still in use. Target temperature is 120 degrees and pressure 16 bar.