Iceland - Direct Uses




district heating



Industrial process heat



Greenhouse heating



fish farming



Snow melting



bathing and swimming



 geothermal heat pumps



Taken from: Geothermal Development in Iceland 2010-2014 Árni Ragnarsson

Total thermal installed capacity in MWt


Direct use in TJ/year


Direct use in GWh/year


Capacity factor



Country Update: Utilization of geothermal energy has played a major role in the energy supply of the country for many years. The country’s geological characteristics related to its location on the Mid-Atlantic Ridge have endowed the country with an abundant supply of geothermal resources. The share of geothermal energy in the primary energy supply of Iceland is about 68%. The utilization of geothermal water for house heating and other direct uses started early in the twentieth century. Space heating is by far the most important direct utilization, covering 90% of all energy used for house heating in the country. Other sectors of direct use are for swimming pools, snow melting, industrial applications, greenhouse heating and fish farming. About 30 separate geothermal district heating systems are operated in towns and villages in the country and additionally some 200 small systems in rural areas. These smaller systems supply hot water to individual farms or group of farms as well as summerhouses, greenhouses and other uses. The Reykjavik district heating system is the largest in the country, serving over 200,000 people or about 67% of the Icelandic population, and about 100% of the population of the city. There are about 175 swimming pools in the country of which 150 are geothermally heated. Most of the pools are open all year, and serve recreational purposes and for swimming lessons. Many are located outdoors. Geothermal snow melting covers around 1,200,000 m², mostly in the capital city. The largest industrial use of geothermal heat is the seaweed drying plant Thorverk, located in west Iceland. Other industrial applications include heat to produce salt from the ocean. Commercial liquid carbon dioxide is produced from the Heidarendi geothermal field. Geothermal energy has been used for about 35 years for drying fish. CO2 emissions from a power plant are used to produce methanol to blend with gasoline to fuel cars. Geothermal heating of greenhouses started in 1924, which today, covered about 194,000 m2, including glass houses and plastic tunnels. Fish farming produces about 7,000 tons annually on 70 fish farms, mainly arctic char and salmon. Geothermal heat pumps are used mainly in Akureyri to supplement the district heating system in northern Iceland.

Taken from: John W. Lund and Tonya L. Boyd
Published in Direct Utilization of Geothermal Energy 2015 Worldwide Review

Total thermal installed capacity in MWt:1,826.0
Direct use in TJ/year24,361.0
Direct use in GWh/year6,767.5
Capacity factor0.42

Due to its location the country has very favorable conditions for geothermal development. The geothermal resources are utilized for both electricity generation and direct heat applications. It provides 62% of the nation’s primary energy supply, with space heating the most important direct-use, providing 89% of all space heating in the country. 
The largest geothermal district heating system is in Reykjavik where 197,404 people are served with an installed capacity of 1,264 MWt and peak load of 924 MWt.
Two other large district heating systems are located on the Reykjanes peninsula which serves about 20,000 people and the Akureyri system in northern Iceland serving about 23,000 people.

There are 135 swimming pools in the country that use geothermal heat, generally open throughout the year.
Snow melting has been recently increased to where 820,000 m2 are heated throughout the country, with most in Reykjavik. Most of the heat energy comes from the return water from space heating systems.

Industrial uses include the seaweed drying plant at Thorverk; carbon dioxide production at Haedarendi; and fish drying by 18 small companies, producing about 15,000 tonnes of dried cod heads for export. The diatomaceous earth drying plant at Kisilidjan has been closed. Other industrial applications using geothermal heat are salt production, drying of imported hardwood, retreading of car tires, wood washing, curing of cement blocks, and steam baking of bread at several locations.
After space heating, heating of greenhouses is the oldest and most important uses of geothermal energy. Crops produce include vegetables (55%) and flowers (45%), with an estimated 17.5 ha in operation at present. Fish farming has increased to around 10,000 tonnes in 40 plants by 2006, with salmon the main specie; however, arctic char and cod production are increasing rapidly.

Geothermal energy installed capacity and annual use are:

1,380 MWt and 17,483 TJ/yr for district heating;
40 MWt and 677 TJ/yr for greenhouse heating;
67 MWt and 1,835 TJ/yr for fish farming;
65 MWt and 1,642 TJ/yr for industrial process heat;
200 MWt and 1,448 TJ/yr for snow melting;
70 MWt and 1,256 TJ/yr for bathing and swimming;
4 MWt and 20 TJ/yr for geothermal heat pumps (2 large units in Akureyri);

for a total of 1,826 MWt and 24,361 TJ/yr (Ragnarsson, 2010).

Taken from the paper by John W. Lund, Derek H. Freeston, and Tonya L. Boyd: "Direct Utilization of Geothermal Energy 2010 Worldwide Review"; published in Proceedings of the World Geothermal Congress 2010, Bali, Indonesia, 25-29 April 2010