The Nesjavellir geothermal field is a high-enthalpy geothermal system within the Hengill area of SW-Iceland.  Construction of the geothermal power plant began in 1987 and the first stage of the thermal plant was commissioned in 1990, following an intensive drilling and testing phase in the 1980s. The last 30 MWe turbine generator unit was commissioned in 2005. The plant owner is Orkuveita Reykjavíkur.

Nesjavellir Geothermal Power Plant details:

• Flash steam, combined cycle geothermal plant
• 120 MWe, developed in three phases
• 300 MWth, or 1,800 liters/second of hot water at approximately 83° C
• 25 boreholes were drilled, from 1,000-2,200 meters

Mannvit Services:  

• Project management
• Overall plant design
• Environmental impact assessment and report
• Detailed mechanical design of the plant
• Detailed design of HVAC systems