Copyright/ Landsvirkjun

Theistareykir Geothermal Power Plant

Energy Solutions

Landsvirkjun (the national power company of Iceland) and COWI teamed up to construct a 90 MW power plant in Theistareykir to meet the growing demand for renewable energy across the country.  

Theistareykjavirkjun is a geothermal power plant at Theistareykir, one of the many high-temperature geothermal areas in Iceland, located 300 metres above sea level. With its two turbine units, each with a 45 MW capacity, the power plant can supply 160,000 Icelandic homes with sustainable power. And with an immense estimated potential capacity of up to 200 MW, it can also meet future demands.  

Landsvirkjun, COWI and Verk√≠s collaborated on the design of the power plant, revolving around efficiency and effective utilisation of renewable energy resources. Sustainability was the overarching guideline along with responsible construction.  

COWI also supported Landsvirkjun with the preparation of tender documents and technical assistance during construction and testing. We also handled the design and technical supervision of boreholes and borehole drilling, the evaluation of the size of the geothermal area, the project design for high-voltage lines and substations, and the environmental impact assessment (EIA). 

In 2019, the Theistareykir Geothermal Power Plant was awarded the prestigious International Project Excellence Award (IPMA) in the category large and mega-sized projects for being both on time and budget, as well as constructed in harmony with the environment and surrounding nature. 



90 MW installed capacity  
738 GWh generation capacity 
2002 First exploration well 
200 MW EIA






  • Project management for the consultants 
  • Tender and procurement documents 
  • Detail design, supervision assistance for mechanical installations 
  • Supervision assistance for control equipment installation 
  • EIA for the plant and transmission lines 
  • Design of high-voltage transmission lines and substations 
  • Well design and drilling supervision 
  • Reservoir modelling