Bathing & Recreation
Until early last century, Iceland's geothermal energy was limited to bathing, laundry and cooking. These uses are still significant. After space heating, and electricity generation, heating of swimming pools is one of the most important uses of geothermal energy. There are about 169 recreational swimming centers operating in Iceland, 138 of which use geothermal heat, not counting natural hot springs nor the Blue Lagoon, the Mývatn Nature Baths and Nauthólsvík geothermally heated beach.
Based on their surface area, 90% of the pools are heated by geothermal sources, 8% by electricity, and 2% by burning oil and waste.
Of the geothermally heated pools, about 108 are public and about 30 are pools located in schools and other institutions. The combined surface area of all swimming centers in Iceland is about 36,700 m2, not including the surface area of shallow relaxation pools. Most of the public pools are open-air pools used throughout the year. The pools serve recreational purposes and are also used for swimming lessons, which are compulsory in schools. Swimming is very popular in Iceland and pool attendance has increased in recent years. In the greater Reykjavik area alone there are 17 public swimming centers pools. The largest of these is Laugardalslaug with a surface area of 2,750 m2 plus eight hot tubs in which the water temperature ranges from 35 to 42°C. Other health uses for geothermal energy are the Blue Lagoon and the Health Facility in Hveragerdi, comprising geothermal clay baths and water treatments. The latest development in the water health sector is a bathing facility at Bjarnarflag that uses effluent geothermal water from wells.
Typically, about 220 m3 of water or 40,000 MJ of energy is needed annually for heating one m2 pool surface area. This means that a new, medium-sized swimming pool uses as much hot water as is needed to heat 80-100 single-family dwellings. The total annual water consumption in geothermally heated swimming pools in Iceland is estimated to be 6,9 million m3, which corresponds to an energy use of 1,300 TJ per year.