Iceland - Electricity Generation

The country's geological characteristics (its location on the Mid-Atlantic Ridge) are favoring the large utilization of geothermal energy in the energy supply of Iceland. The share of geothermal energy in the primary energy supply of Iceland is about 68%, reaching 90% of all energy used for house heating. Geothermal electricity generation started 45 years ago and has now reached 29% of the total electricity needs. The total installed capacity is now above 650 MWe and the annual generation about 5,250 GWh, from the following fields: Námafjall 3 MWe, Hellisheidi 303 MWe, Húsavík 2 MWe, Krafla 60 MWe, Nesjavellir 120 MWe, Reykjanes 100 MWe and Svartsengi 76 MWe (Ragnarsson, 2015).

Development since WGC2010: 90 MWe of two new units at Hellisheidi IV.

Installed capacity 665 MWe                   
Geothermal Electricity 5,245 GWh/y

Source:  Ruggero Bertani, Geothermal Power Generation in the World 2010-2014 Update Report


Installed geothermal generating capacity (December 2009) in MW 

Hellisheidi215.0
Nesjavellir120.0
Reykjanes100.0
Svartsengi74.0
Krafla60.0
Namafjall3.0
Husavik2.0
Total575.0

The geothermal electricity production in Iceland has increased significantly since 2005 (about 370 MW, 184%, the highest value among the countries with a relevant geothermal electricity production), with the installation of new plants in Nesjavellir (30 MW), Hellisheidi (the entire field started its production after 2005: 5 units for 213 MW), Svartsengi (30 MW) and Reykjanes (2x50 MW). The most important fields of the island are listed below

Krafla: in the northern part of the island, its operation started in 1977 from Landsvirkjun, with several initial problem in producing enough steam for feeding the plants, due to the volcanic activity in the area. Now, after 20 years, some degassing of the productive reservoir has been achieved, and two 30 MW double flash turbine are in operation with additional 40 MW planned.

Bjarnaflag (Námafjall): the oldest geothermal field in Iceland is still in operation since 1969 (Landsvirkjun), with an old 3 MW back-pressure unit.

In Husavik an experimental Kalina binary unit (using 120°C hot water, operated by Orkuveita Husavikur) of 2 MW has been installed in 2000, but only in 2008 it started a commercial operation.

Hellisheidi: on the active volcanic system of Hengill; it has 210 MW and 400 MWth of thermal output for district heating of the Reykjavik area (27 km away); the electricity is supplied mainly to local aluminum refineries. All the plants of the field have been commissioned after 2005 by Orkuveita Reykjavikur: 2x45 MW in 2006 (Unit I), 35 MW in 2007 (Unit II) and again 2x45 MW in 2008 (Unit III).

Nesjavellir (Orkuveita Reykjavikur): in the southern part of the country, four 30 MW units (total 120 MW), combining heat/electricity production with 300 MWth for district heating (about 1,800 l/s of hot water). The most recent unit has been commissioned in 2005.

Reykjanes: in south-western peninsula, operated by Hitaveita Sudurnesja, it has been commissioned in 2005 and 2006, with two 50 MW units, and additional 50 MW under construction.

Svartsengi: near the International Airport and the famous outdoor swimming/spa facilities of Blue Lagoon (visited yearly by about 400,000 people, probably the most popular Icelandic touristy attraction), feed by the discarded water (rich in surplus mineral) of two flash units (reservoir fluid at 240°C) for about 66 MW and a 8 MW binary unit (Hitaveita Sudurnesja); there is also an important additional hot water production of 150 MWth for district heating. Also here the most recent addition was a 30 MW unit in 2005. 
 

Other Projects

The Icelandic Deep Drilling Project (IDDP) has been finally placed nearby Krafla geothermal area, in the Northern part of the country. The aim of the project is the exploitation of supercritical fluid at 4-5 km depth and 400-600°C of temperature. Unfortunately, in 2009, the well reached a magma body and the project has been placed in stand-by.

An agreement has been signed between the Century Aluminum Co and two major Icelandic geothermal producers (Hitaveita Sudurnesja and Orkuveita Reykjavikur) for supplying electricity to the production of an initial amount of 150,000 tons of aluminum per year, utilizing 250 MW of geothermal electricity. The initial stage of the project will be commissioned in 2010. The agreement is expandable up to 435 MW, for a production of 250,000 tons of aluminum. This will be a very efficient way of exporting the surplus of cheap and abundant geothermal electricity production from Iceland.

The total installed capacity of the country is 575 MW, and additional 230 MW under construction. The country with 300,000 inhabitants is 100% renewably powered, with 25% of its electricity and 90% of heating needs provided by geothermal energy. Geothermal energy contribution to the total energy consumption sums up to 62%, probably the highest in the world.

 

Space Heating

The main use of geothermal power is for space heating which amounted to about 25 PJ per year; an extensive district-heating systems has been realized into the country. The share of geothermal heat in space heating is almost 90%, whereas the remainder is mainly heated with electricity (which results 100% renewable), so that fossil fuels account for only a small fraction of the total.

As an example, the Reykjavik district heating system, serving 200,000 inhabitant of the capital, with a thermal capacity of 1.2 GWth and about 80 million m3 of hot water provided yearly, can be considered as one of the most important in the world, 100% heated from geothermal energy.

As final remark, the growing on geothermal electricity is presently in a clear impressive exponential phase.

Taken from Ruggero Bertani’s paper, " Geothermal Power Generation in the World 2005–2010 Update Report ", published in Proceedings of the World Geothermal Congress 2010, Bali, Indonesia, 25-29 April 2010.