Survey of Energy Resources 2007
Geothermal Country Notes
Geothermal energy resulting from Iceland's volcanic nature and its location on the Mid-Atlantic Ridge has been utilised on a commercial scale since 1930. The high-temperature resources are sited within the volcanic zone (southwest to northeast), whilst the low-temperature resources lie mostly in the peripheral area. A realistic assessment of Iceland's potential for electricity production has been put at 20 TWh annually, after taking into account economic factors, environmental considerations and technological elements.
Iceland's total annual primary energy consumption was 550 GJ per capita in 2006 - amongst the highest in the world. Geothermal energy provides about 55% of the total primary energy supply while the share of hydropower is 16%, oil 26% and coal 3%. The principal use of geothermal energy is for space heating, where about 89% of all energy used for house heating comes from geothermal resources. There is a total of 26 municipally-owned geothermal district heating systems located in the country, the largest of which is Energy Reykjavik, serving 190 000 people. In addition to the heating of houses, direct use of geothermal energy is made for swimming pools, snow melting, industrial use, greenhouse and fish farming. In 2005 total direct heat use was 23 600 TJ from an installed capacity of 1 800 MWt.
In recent years there has been an expansion in Iceland's energy-intensive industrial sector and thus a considerable increase in electricity demand. This has been met partly by increasing geothermally-produced electricity. The total capacity of geothermal power plants has increased from 50 MWe in 1998 to the 2006 level of 422 MWe. Of 9 925 GWh total electricity generation in 2006,
2 631 GWh or 27% came from geothermal energy, 73% from hydro and a negligible amount from fossil fuels.
Two co-generation power plants are in operation. The Svartsengi energy plant, in operation since 1977 has a capacity of 200 MWt for hot water production and 46 MWe for electricity generation, of which 8.4 MWe comes from binary units using low-pressure waste steam. The effluent brine is disposed of in The Blue Lagoon, a bathing and balneological facility which is becoming a major tourist attraction. A new 30 MWe generator is being installed at Svartsengi, with completion scheduled for the end of 2007.
At the Nesjavellir energy plant there is an installed capacity of 250 MWt for hot water production and 120 MWe for electricity production. The primary purpose of the plant is to provide hot water for the Reykjavik area, 27 km away.
Two conventional geothermal power plants are in operation: Krafla, a 60 MWe double-flash condensing plant and Namafjall a 3 MWe back-pressure system. At Husavik generation of electricity began by installing a binary plant of the Kalina type. In generating 2 MWe of electricity, the geothermal water is cooled from 120ºC to 80ºC. The water is then used for district heating of the town.
It is planned to add a further 40 MWe to the plant at Krafla and a new plant in the same area is being considered.
Two new power plants began operating in 2006: the first, Reykjanes, 100 MWe (2 x 50 MWe) in May, and the second, Hellisheidi, 90 MWe, in October.
Although the growth of space heating has been fairly slow in recent years, a distinct increase of geothermal's share (from 89% to 92%) is foreseen, owing partly to demographic movement and partly to further exploration for sources of geothermal heat.