Theistareykir Geothermal Power Plant

Landsvirkjun (Iceland’s national energy company) is working on building the first stage of a geothermal plant with a 90 MW capacity at Theistareykir [icelandic: Þeistareykir] in NE Iceland. Over a period of 10 years, Landsvirkjun invested heavily in researching geothermal in the area. Mannvit, in collaboration with Verkis, handled the design of the power stations and preparation of tender documents for up to 90 MW of electricity.

The plant will have two turbine units, each with a 45 MW capacity. Procurement of all machinery and electrical equipment has been completed. Mannvit-Verkís worked on the design of the power plant and preparation of tender documents. Technical assistance will also be provided during construction and testing. Mannvit prepared project design reports, designed boreholes, oversaw technical supervision of the drilling of the current boreholes and evaluated the size of the geothermal area. Mannvit also carried out project design for high voltage lines and substations, as well as evaluating the environmental impact and performing a joint environmental assessment of high voltage lines and power plants in the area.

The plant's 1st phase of 45 MW is well underway, projected to go online in 2107 and the 2nd phase another 45 MW in 2018.

Cornerstone at Theistareykir Geothermal Power Plant -

Five exploration wells were drilled in 2002 and 2003. The first production well drilled in 2002 was promising and yielded 6 MWe. Landsvirkjun plans to build the plant in two 45 MWe phases. Seven production wells have been drilled to date, providing enough steam for the 1st phase. 

Landsvirkjun is owned by the Icelandic state and the country's largest electricity generator, processing 75% of all electricity used in Iceland from hydroelectric power, wind and geothermal energy. Landsvirkjun operates 16 power stations in Iceland. 

  • Project management for the consultants
  • Preparation of tender documents and procurement documents
  • Detail design, supervision assistance for mechanical installation
  • Supervision assistance for control equipment installation
  • EIA for the plant and transmission lines
  • Design of HV transmission lines
  • Design of substations
  • Well design
  • Drilling supervision
  • Reservoir modelling


90 MW 
Installed capacity in 2 phases
First exploration well
200 MW 

"There are many challenges due to the location of the plant. Theistareykir is an uninhabited area, more than 300 m higher than sea level, where there is heavy snow. Despite this, construction work could be done during the winter, thanks to the good roads that had been built. Construction of the plant’s powerhouse commenced in May 2015 and is well underway, and a steam system has been installed. The work is on schedule, and the first unit will be ready for operation in autumn 2017. Sufficient power for the first stage has been ensured, and the project is going as well as could possibly be expected."

Claus Ballzus

Project Manager


Theistareykir GPP project (in Icelandic) - video by Landsvirkjun