Tuesday, February 11, 2020

Iceland: 90 MW Theistareykir Geothermal Power Plant Steam Supply System Explained

Steam Supply System for 90 MW Theistareykir Geothermal Power Plant - Design, Operation and Experience (Mannvit)

Theistareykir Geothermal Power Plant (Courtesy Mannvit)
The steam supply for Theistareykir Geothermal Power Plant is a single flash cycle providing steam for 2x45 MWe turbine units whereas the separated water is mixed with steam condensate from the units and reinjected. The steam supply has been in operation from end of 2016.

The paper “Theistareykir Geothermal Power Plant, description of the steam supply system: Design, operation and experience gained” describes the design and layout of the steam supply, the characteristics of the steam wells, operation and control strategy of the steam supply and its ability to cope with variable load.  More information on the geothermal project as a whole.

The steam supply system comprised of the steam wells, steam pipelines, steam gathering pipelines, steam separators, main steam pipelines, steam control valves, mist eliminators, reinjection pipeline, condensate mixing system and reinjection wells. The steam wells are located on five drilling areas from where most of the wells are directionally drilled. The average length of the wells is 2 500 m and their vertical depth ranges from 1 800 – 2 400 meters, each well producing steam in the range equivalent to 5-21 MWe of electrical power. In the operation of the wells, some of the wells have been shown to have fluctuation in the output and some decline has been noted.