Hellisheiði Power Plant, Extension

The Hengill Area is one of Iceland‘s largest geothermal areas, approximately 100 km² in size. That is not to say it is all one and the same cauldron, but rather a composite of the Hveragerði volcano (Grændalur), Ölkelduháls and the geothermal area of the Henglafjöll mountains.

Considerable power plant construction has already taken place in the area, including power plants at Hengill and Nesjavellir. In the 2nd phase of the Master Plan for Hydro and Geothermal Energy Resources, further proposals for power plants at Grændalur and Bitra are classified as protected, proposals at Gráuhnúkar, Hellisheiði, Hverahlíð and Meitillinn are classified as exploitable, while projects at Innstidalur, Ölfusdalur and Þverárdalur await further assessment.

The hot springs and geysers with siliceous sinter deposits at Hveragerði and Reykjar are characteristic of the Grændalur area, along with the numerous natural springs that are formed during rockslides. Steam fumaroles are common in the area and often coincide with cracks formed in the large earthquakes that periodically hit South Iceland.

At Ölkelduháls, there is a lot of geothermal activity of various kinds. Numerous large mudpots, muddy hot springs and fumaroles are dotted around the area. In several places, vestiges of powerful steam explosions can be found. Mineral salt and sulphuric deposits predominate. At Klambragil canyon at the bottom of Reykjadalur valley, great bubbling hot springs can be found, from which a hot stream runs before joining a colder current and creating an optimal bathing spot in the river Reykjadalsá.

A large portion of the area is on the Nature Conservation Register, i.e. the drainage basin of Grændalur valley, Reykjadalur valley and Hengladalir valleys. There are several popular hiking routes in the area.

Photo © Mats Wibe Lund

Hengill and the surrounding highlands form a part of the mountain range that encircles the capital region, from Skarðsheiði and Esja in the north to Keilir in the south. Hengill is one of the most diverse and popular outdoor destinations accessible on daytrips out of Reykjavík, be it in summer or winter. It is the second largest geothermal area in the country (excluding glacial regions) and provides the entire population of Iceland’s southwest with hot water and electricity.

Photo © Hlynur Stefánsson

Hellisheiði Power Plant harnesses the geothermal energy and natural hot water in the southern part of the Hengill area, employing geothermal energy from around 50 boreholes to produce electricity. The power plant has a capacity of 303 MW. 

The current Hellisheiði Power Plant produces 303 MW but there are plans to extend the geothermal power plant by 90 MW, with two 45 MW turbines.

Despite promises of solutions for hydrogen sulphide pollution in the atmosphere and waste water at the power plant, neither has been fulfilled. At this writing in December 2012 an 8-year period has been prompted in which to seek ways to fix the problem. 

For geothermal power plants in Iceland it is generally presumed that they will last no longer than 50 years. Hellisheiði Power Plant might therefore only have a lifespan of 50 years.

Photo © Christopher Lund