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The Esrange Space Centre in Kiruna in northern Sweden has invested over £100,000 in a ground source energy system. Energy from beneath the earth’s surface is now used to heat the whole of the hotel in which the space scientists are accommodated; fifteen boreholes and three NIBE Fighter 1320 pumps connected in series make sure that no-one has to shiver even when outside temperatures are as low as -35°C (-31°F).
Esrange is something as unique as a Swedish space centre. The site in northernmost Sweden is used for launching rockets and stratospheric balloons, and also has ground stations for satellite control and communication.
“This is one of the biggest ground source energy set-ups in the whole of Sweden”, explains NIBE regional manager, Ingemar Jonsson. The hotel has 97 bedrooms, and provides accommodation for scientists and clients from all over the world. The total area to be heated is 2,600 m². The hotel was originally heated using an electric boiler, but when the premises were extended in 2004 heating costs would have gone through the roof, so the management decided to investigate the alternatives.
“It didn’t take us long to realise that it would make economic sense for us to install a ground source heating system”, explains Jens Fjellborg, who is premises manager at Esrange. The total investment cost for the new system amounted to SEK 1.5 million (approximately £112,000), and it was calculated that after ten or eleven years of reduced electricty costs, the new system would have paid for itself.
“The fact is that we will be reaching break-even point even sooner than we estimated. Electricity prices have been increasing steadily ever since we installed the system, and it looks as if they’re going to keep on rising”, says Jens Fjellborg.
“We save about 270,000 kWh a year, which works out as an annual saving of about 200,000 kronor (approx. £15,000) at today’s energy prices!” In other words, the investment will have paid for itself within seven or eight years – everything after that is pure profit.
Fifteen boreholes, each of them 170 m deep, have been drilled in an area 100 m by 100 m. All the boreholes contain groundwater at a depth of fifteen metres, and the pipes are not insulated beneath surface level, so the system can also make use of the heat energy just beneath the ground surface.
Three 40 kW Fighter 1320 pumps connected provide a total of 120 kW. This is enough power to meet the heating requirements of the whole hotel complex, even when temperatures sink to –30 or –35 degrees C.