Geothermal Power Plants Brochure
Geothermal Power Plants Brochure
Geothermal Power Plants Brochure
Power Plants
Leaders in
Geothermal Energy
Geothermal Power Plants
Geothermal power plants utilize heat energy from the Earth to
produce electricity and sometimes for combined heat and power
(CHP). They are cost effective, reliable and environmentally
friendly. And, though previously restricted to certain geographic
locations, technological advances in drilling and plant design allow
for the development of what were once thought to be non-viable
resources. As a result, more and more public and private entities are
looking into geothermal power as part of their strategy to mitigate
global warming while still meeting growing energy demands.
Additional information:
Claus Ballzus: claus@mannvit.is
Kristinn Ingason: kristinn@mannvit.is
Project example:
Nesjavellir
Power Plant
The Nesjavellir geothermal field is a high-enthalpy geothermal The Nesjavellir power plant is a combined heat and power plant
system within the Hengill area of SW-Iceland. Construction of (CHP) wherein it produces electricity and hot water for district
the geothermal power plant began in 1987 and the first stage heating. The plant itself is a combined cycle plant, wherein a
of the thermal plant was commissioned in 1990, following an mixture of steam and geothermal brine is transported from the
intensive drilling and testing phase in the 1980s. The last 30 wells to a central separation station at 200° C and 14 bars.
MWe turbine generator unit was commissioned in 2005.
From there the fluid (steam and liquid) goes into a steam
Nesjavellir Geothermal Power Plant details: separator and the two phases are separated. Moisture is
• Combined cycle geothermal plant removed from the steam, which is then sent through the
• 120 MWe, developed in three phases turbine after which it is condensed in a condenser. Within
• 300 MWth, or 1,800 liters/second of hot water at approxi- the condenser fresh water is preheated. The preheated fresh
mately 83° C water is then run through a system of heat exchangers, which
• 25 boreholes were drilled, from 1,000-2,200 meters utilize the heat from the liquid part of the brine after the
steam separator. The fresh water is heated to the required
Mannvit Services: temperature and sent through deareators, which remove the
• Project management bulk of the oxygen. Then finally a small amount of geothermal
• Overall plant design steam containing acidic gases (hydrogen sulfide) is injected into
• Environmental impact assessment the water to remove any remaining oxygen, thereby preventing
• Detailed mechanical design of the plant corrosion and scaling.
• Detailed design of HVAC systems
• Bid preparation and tender evaluation This hot water is then pumped to a large storage tank at an
• Site supervision elevation of 406 meters. From there, the hot water flows
• Commissioning by gravity to two smaller storage tanks on the outskirts of
• Acceptance test Reykjavik to be used for heating and hot tap water.
• Training of operators
Additional information:
Claus Ballzus: claus@mannvit.is
Kristinn Ingason: kristinn@mannvit.is
Project example:
The plant was installed in 1999 near the small town of Husavik,
in Northern Iceland. This binary geothermal plant produces 2
MW from a geothermal brine flow of 90 kg/s at 120 °C. The plant
was commissioned in mid-2000. The outgoing brine leaves the
plant at 80 °C and is then used for district heating and other
industrial uses.