Sustainable Geothermal Utilisation
The 90 MW Þeistareykir geothermal project will be executed in two 45 MW phases. The first 45 MW phase will be an initial step in the responsible development of sustainable geothermal utilisation in the northeast of Iceland. Extensive preparation work was carried out at Þeistareykir this year. The unique nature of the area was considered during the execution of all preparation work and an emphasis was placed on working in harmony withthe environment and in consensus with society.
Preparation measures for the power station
The tender design process for Þeistareykir began in the autumn of 2011 when the design work was awarded to the consortium of engineering consultants Mannvit and Verkís. The two companies had just completed design work on the Hellisheiði Geothermal Station, one of the largest design projects completed in Iceland in the last few years and an example of Icelandic ingenuity in the geothermal sector. The main objective was to design a profitable, reliable power station in harmony with its surroundings and the environment. One of the main focuses was the environment, considering issues such as the sustainable utilisation of the geothermal resource and groundwater, the re-vegetation of disturbed areas and land reclamation to replace grazing land.
Tender design work was completed in the first part of 2014 and tenders were released in March for two turbines, steam condensers, cooling towers and connected equipment. Four feasible offers were submitted.
The proposed powerhouse can be seen on the right and has two turbine halls. The cooling towers can be seen in the middle of the picture as well as the mist eliminator, where the pipeline runs to the steam separator (at the top of the picture). The well head and muffler can be seen to the far left. Construction work is estimated to begin in May, 2015.
Overview of preparation work completed in 2014
Preparation measures have been undertaken with a view to beginning work at Þeistareykir, at short notice. Groundwork on the powerhouse site was completed and water utilities were constructed during the summer of 2014. Extensive exploration drilling also took place. Drilling work included water access, re-injection and drainage wells for the power station as well as research wells to support further research on groundwater. The first 15 km of the access road to the site was completed and roadside edges were completed.
Construction work on the road will be completed in the summer of 2015 including road surfacing for theentire length of the road, up to the station.
Other preparation projects included the set-up of work camps for Landsvirkjun and the contractors, the set-up of an electrical distribution system and telecommunications in the area, in cooperation with Landsnet.
Wells are opened for discharge at full output during capacity testing to simulate the operation of a 45 MW power station. The objective is to assess if and how the operation of the geothermal station at Þeistareykir would affect the geothermal reservoir. Capacity testing is a component in verifying the sustainability of the geothermal area and has been ongoing since October, 2014.
In harmony with the environment and in consensus with society
The unique environment of the Þeistareykir area has been an important consideration since preparation work for the Þeistareykir project began. The area was previously almost untouched, with the exception of archaeological artefacts and traces of sulphur mining from previous centuries. Plans for development have therefore included the demarcation of areas protected for archaeological and environmental reasons to prevent any disturbance to these areas.
Visual aspects have also been considered during the design process for the power station and landscaping and finishing work is therefore completed alongside construction work. Examples of this include sowing on road verges and the utilisation of vegetation cover extracted from construction areas to vegetate the roadside and to cover earthen berms.
37,118 larch and birch plants were planted in lupine-rich areas in the Reykjaheiði heathland area in Norðurþing and in close proximity to the power station road. There are plans to plant a further 30 to 40 thousand plants next year.
Earthern berms are constructed to minimise the visual impact of wells and pipelines. The photograph shows the area overlooking drilling area ‘A’ from the Þeistareykir cabin and down to the Bæjarfjall Mountain. The berm will eventually be covered with vegetation.
This photograph shows the newly constructed road from Húsavík to Þeistareykir. An emphasis was placed on completing roadside edges to ensure that the road merged with the surrounding environment.