Landsvirkjun

Kröflustod Power Station

At Krafla Power Station, high- and lowpressure steam from 18 boreholes drives two 30 MW turbines.

Built by the Icelandic government, Krafla came under the ownership of Landsvirkjun in 1985. Construction began with trial boreholes in 1974, the first turbine unit started up in August 1977, and regular operations began in February 1978. Krafla’s development was a pioneering endeavour, hampered by political feuds for years, as well as volcanic activity and technical complications.

The installation of the station’s second turbine unit began in 1996. New boreholes were drilled and older ones were repaired. Steam extraction has been successful with improved technology, among those being directional drilling. Since additional drilling and renovations were completed in 1997, Krafla has been operated at its full 60 MW capacity.

30 MW
Geothermal Power
30 MW
30 MW
Geothermal Power
30 MW
60 MW
60 MW
Installed capacity
2 x 30 MW
2 steam turbines
500 GWh p.a.
Generation capacity
1977
Brought online
1997
Refurbished

Harnessing Geothermal Energy

Energy from the Earth’s core

Geologically, Iceland is relatively young. The country is a volcanic island, located on a hotspot on the Mid-Atlantic Ocean Ridge, where the North American and Eurasian plates meet. Geothermal heat is considerable in most parts of the country, and in many places hot water from just below the surface is used to heat homes and for energy production.

When precipitation runs through the hot bedrock, the water heats up, resulting in hot springs on the surface and steam chambers underground. In low-temperature areas, hot water is primarily used to heat homes, while high temperature areas produce hot steam under pressure.

Steam is led from boreholes to turbines inside the powerhouses of geothermal plants, transforming thermal energy into electricity. The total installed capacity of geothermal energy in Iceland is 575 MW.

Landsvirkjun operates two geothermal plants with an installed capacity of 63 MW.

Specifications

Kröflustöð
Uppsett afl: (2x30 MW) 60 MW
Orkuvinnslugeta: (60 MW) 480 GWst
Í fullum rekstri nýtir stöðin um 110 kg/s af 7,7 bara mettaðri háþrýstigufu og 36 kg/s af 2,2 bara mettaðri lágþrýstigufu.
Helstu gastegundir í jarðgufunni
Koldíoxíð: (CO2) 90-98%
Brennisteinsvetni: (H2S) 2-10%%
Upphafleg hönnun
Virkjun: VST hf., Rafteikning hf. og Rogers Engineering Co. Inc.
  VST hf. og Virkir hf.
Gufuveita: Manfreð Vilhjálmsson og Þorvaldur Þorvaldsson
Raflína til Akureyrar og Austurlands hönnuð og reist af: Rafmagnsveitum ríkisins
Jarhitarannsóknir og umsjón með borunum eftir gufu: Orkustofnun
Framleiðendur búnaðar
Hverflar, rafalar og vélbúnaður: Mitsubishi Heavy Industries, Japan
Kæliturnar: Marley, Bandaríkjunum
Spennar: EGB, Austurríki
Lágspennubúnaður: Alstom, Frakklandi
Helstu verktakar 1975-1977
Jarðvinna og byggingar: Sniðill hf., BSHSÞ, Miðfell hf.
Jarðboranir: Jarðboranir ríkisins
Málmsmíði og vélauppsetning: Slippstöðin hf., Héðinn/Stálsmiðjan/Hamar og Stjörnu-stál hf.
  Rafafl hf.
Raflagnir
Uppsetning vélar 2 og stækkun gufuveitu 1996-1998: Verkfræðistofa Guðmundar og Kristjáns hf. og Rafteikning hf.
Hönnun og eftirlit: Verkfræðistofa Guðmundar og Kristjáns hf. og Rafteikning hf.
Helstu verktakar
Boranir: Jarðboranir hf.
Vélbúnaður: Mitsubishi Heavy Industries, Alstom
Raf- og stjórnbúnaður Lögstrup
Uppsetning vélbúnaðar og undirstöður: Vélsmiðjan Gils, Vélsmiðjan Grímur, Sniðill
Uppsetning rafbúnaðar: Ljósgjafinn, Rafeyri, Rafiðn og Öryggi