Geothermal Development

Mannvit offers a comprehensive suite of geothermal development services and, has been doing so for more than 50 years. The Mannvit team of geothermal specialists that includes engineers, scientists and technicians who can handle all aspects of geothermal development from start to finish. 

The Mannvit team has offered geothermal development services to projects in Iceland, Europe, Asia and the Americas and can manage the entire geothermal development process or defined parts as the client wishes. 

Hitaveita Hellisheiðarvirkjun stækkun - Hellisheidi geothermal heating plant

Mannvit offers its clients the full range of technical and engineering services in each phase of geothermal development, including:

  • Geothermal exploration
  • Reservoir engineering
  • Drilling engineering, management and supervision
  • Field development and steam gathering system design
  • Geothermal plant design
  • Start-up and commissioning
  • Operations and maintenance
  • Teaching and training (knowledge transfer)

Phases of geothermal power development 
in high-temperature areas

  • Exploration and reconnaissance
  • Pre-feasibility
  • Feasibility
  • Detailed design and construction
  • Operations and maintenance

Exploration and reconnaissance phase

The fundamental purpose of the exploration and reconnaissance phase is to determine if there exists a commercially exploitable geothermal resource.  The first assignment is to perform a desk study, which entails collection and analysis of all available existing data regarding the geothermal field and the environment in order to define the resource and scope of the following exploration activities. The desk study is followed up by field work, which usually includes:

  • Geological mapping of important geological features in order to get acquainted to the geological structure of the geothermal system
  • Geo-chemical analysis of fluids from surface manifestations or shallow wells if available to get indications on the reservoir temperatures
  • Geophysical explorations, like resistivity measurements, gravity and seismic profiling where needed, to get better understanding of the subsurface features of the geothermal resource
  • Drilling of shallow exploration wells (usually 50-300 m) to measure temperature gradients in order to locate the up-flow zone of hot fluids in the geothermal reservoir


Pre-feasibility phase
If the results from the exploration phase are positive, the development moves to the pre-feasibility phase where the exploration becomes more focused on the most favorable location.  Activities in the pre-feasibility phase may include:

  • More focused geophysical exploration
  • Drilling of slim wells (+300 m)
  • Environmental impacts assessment
  • Drilling of deep exploration well
  • Fluid chemical analysis
  • Production potential assessment
  • Pre-feasibility data analyzed and reported

Feasibility phase

In the feasibility phase, the commercial level of the geothermal resource is generally demonstrated by the following activities:

  • Environmental impact assessment
  • Drilling of production/injection wells
  • Fluid sampling and chemical analysis
  • Well testing and well logging
  • Conceptual modeling
  • Production potential assessment (reservoir modeling)
  • Preliminary design of power plant and surface equipment
  • Feasibility data analyzed and reported

Detailed design and construction

If the geothermal project is feasible, power purchase agreements have been reached and financing is secured, the project moves to the detailed design and construction phase.  Detailed design and constructions begins with the following activities:

  • Production/injection wells and drilling platform design
  • Drilling of production/injection wells
  • Infrastructure facilities design and civil works
  • Detailed design of power plant and steam gathering system
  • Detailed design of power transmission lines and point of access determined
  • Service providers contracted for detailed design, engineering, procurement, construction and project management
  • Construction of the power plant and facilities
  • Training of operators and commissioning

Operations and Maintenance

After commissioning, the geothermal power plant starts to render normal service of providing sustainable energy to the clients. With normal maintenance and responsible reservoir management and utilization, a geothermal power plant can provide renewable energy to the clients for decades. We can assist operators with O&M consulting, both in regards to plant operations and steam field.

Geothermal energy can play a role in the energy matrix of many countries. In 2018, over 300 geothermal district heating systems were in operation in Europe. Geothermal energy development can be a solution to renewable energy base-load needs. Investigate your possibilities.“


Kristinn Ingason

Discipline Manager, Geothermal Energy

+354 422 3122

Þorsteinn Sigmarsson

Director Asia Market

+354 422 3121 // +62 8111 031 094 (ID)


Geothermal Power Plants

Engineering of more than 2000 MW in geothermal power and heating capacity. This project experience in geothermal plant design coupled with world-class geoscience expertise has made us the trusted consultant to project developers, financial and government institutes for the past five decades.