Gunung Salak Geothermal Power plant uses the natural resource of Indonesia's underground geothermal activity, by turning heat into power.
The project activity comprises of a capacity upgrade of an existing geothermal power plant from 3 x 55 MW to 3 x 60 MW, which generates and supplies electricity to the connected grid, the Jamali regional grid.
The capacity upgrade is established by:
- Changing turbine diaphragm of unit 1 and 2
- Modifying the gas extraction system or ejector for unit 3
Project partners include:
- Chena Hot Springs Resort
- Chena Power
- United Technologies Corp.
- Department of Energy
- Alaska Energy Authority
The Chena geothermal power plant came online in late July 2006, putting Alaska squarely on the map for new geothermal technologies. Chena Hot Springs is the lowest temperature geothermal resource to be used for commercial power production in the world. We hope this will be the first step toward much greater geothermal development in the state. The cost of power production, even in semi-remote locations such as Chena, will be reduced from 30¢ to less than 7¢ per kWh once the UTC plant is installed and operational.
The challenge for moderate temperature small scale geothermal development has been to bring the cost down to a level where it is economical to develop small geothermal fields. UTC has been working toward that goal. In the past, small geothermal power plants have been built to order using tailor made components, which has greatly increased both the expense and the lead time for such units.
UTC’s Research Center has teamed up with their sister divisions, Carrier and UTC Power, to reverse engineer mass produced Carrier chiller components to dramatically reduce the cost of production, and allow for modular construction. UTC has already proven this technology with the release of their PureCycle 225 power plant in 2003, which is designed to operate off waste heat applications.
Because the geothermal water at Chena Hot Springs never reaches the boiling point of water we cannot use a traditional steam driven turbine. Instead a secondary (hence, "binary") fluid, R-134a, which has a lower boiling point than water passes through a heat exchanger with 165°F water from our geothermal wells. Heat from the geothermal water causes the R-134a to flash to vapor which then drives the turbine. Because this is a closed loop system virtually nothing is emitted to the atmosphere. Moderate temperature is by far the most common geothermal resource and most geothermal power plants in the future will be binary cycle plants. Here are the steps in the cycle:
- Hot water enters the evaporator at 165ºF (480gpm). After the hot water runs through the evaporator, it is returned to the geothermal reservoir via our injection pump and injection well system. Some of the water is also used to heat buildings on site before it is reinjected.
- The evaporator shell is filled with R-134a, a common refrigerant found in many air conditioning systems. The 165ºF water entering the evaporator is not hot enough to boil water, but it is hot enough to boil the R-134a refrigerant. The evaporator is a giant heat exchanger, with the hot water never actually coming in contact with the refrigerant, but transferring heat energy to it. The R134a begins to boil and vaporize.
- On initial system startup, the vapor bypasses the turbine and returns directly to the condenser via a bypass valve. Once there is adequate boiling/evaporation of the refrigerant, the bypass valve closes and the vapor is routed to the turbine.
- The vapor is expanded supersonically through the turbine nozzle, causing the turbine blades to turn at 13,500rpm. The turbine is connected to a generator, which it spins at 3600rpm, producing electricity.
- Cooling Water enters from our cooling water well which is located 3000ft distant and 33ft higher elevation than the power plant. Cold water (40ºF-45ºF) is siphoned out of this well and supplied to the power plant condenser at a rate of 1500gpm.
- The cooling water entering the condenser and recondenses the vapor refrigerant back into a liquid. As in the evaporator, the condenser only allows heat transfer to occur between the refrigerant (in the shell) and the cold water (in the tubes within the condenser). The two liquids never actually come in contact.
- The pump pushes the liquid refrigerant back over to the evaporator, so the cycle can start again. By doing so, it also generates the pressure which drives the entire cycle.
The Chena Hot Springs Geothermal Resource, like all interior Alaskan hot springs, is located along the margins of a granite pluton. These plutons are ancient (cooled) magmatic bodies that have pushed up into the surrounding rock at some time in the distance past (at least 80 million years ago). These intrusions cooled below the surface to become huge granite geologic formation, called plutons. Plutons can host geothermal systems in two ways. Granitic rock is very brittle and fractures easily. These deep, often steeply dipping fractures can sometimes act as conduits for water which has circulated deep into the earth's crust (picking up heat along the way) to rapidly short circuit' back to the surface. In the case of the Chena system, this short circuit is probably caused by the intersection of two small faults, the primary one located parallel to Spring Creek and identifiable by the string of natural hot springs and seeps along one section of it.
Granite rock is also frequently high in Uranium and Thorium. When these elements decay, heat is generated which is trapped in the host rock, which in this case is the granite pluton. This radioactive decay generates an abnormally high geothermal gradient in the pluton, which means the water does not need to circulate to extreme depths to pick up heat. In the case of Chena Hot Springs, it appears the water is circulating to a depth of approximately 3000-5000ft and reaching a maximum temperature of 250ºF. Chena is working on an exploration project under the Department of Energy to identify and quantify the deep geothermal resource at Chena Hot Springs. This project will culminate in the drilling and testing of a 4000ft hole sited to intersect the geothermal reservoir at depth. For more information on Chena's GRED III project, click here.
The Communication Manager of Pertamina Geothermal Energy (PGE) Adiatma Sardjito said that recently this construction project is in the process of Engineering, Procurement, Construction (EPC). “PLTP Ulubelu will operate in the end of 2012,” he says in Jakarta. Wednesday October 14th, 2010.
He explained that PLN and PGE have dealt about the steam price in US$ 4, 2 cent per kilowatt hour (kwh).
While, Ministry Expert Staff of Communication and Information, MEMR Kardaya Warnika stated that PLTP Ulubelu is one of government’s project in the program of geothermal utilization improvement to encourage renewable energy utilization. “For Ulubelu is in the stage of price evaluation,” he says.
Besides Geothermal Power Plant Ulubelu, he continues, other PLTP projects inserted inside the target of geothermal utilization improvement is PLTP Lahendong (North Sulawesi which is now in the stage of facility working. Finishing PLTP Sarulla (North Sumatera) is in the verification stage by Financial and Development Supervisor Agency (BPKB). PLTP Ulumbu (NTT) in capacity 5 MW is redesigned. (AK)
The Poihipi Power Station is a geothermal power station owned and operated by Contact Energy. It is located on Poihipi Road near Taupo in New Zealand.
The plant produces around 200 GWh pa, utilising geothermal steam from the Wairakei field, and is operated as part of the Wairakei geothermal system.
|Poihipi Power Station|
|Maximum capacity||55 MW|
From the first exploratory drilling in 1974 to reaching full 60MW capacity in 1999, the Krafla geothermal power plant has had an interesting story.
For a while it was uncertain whether Krafla would ever actually enter operation when, early on, large-scale volcanic eruptions occurred only two kilometers away from the station, posing a serious threat to its existence. Work continued, however, and phase one of the power station went on line early in 1977.
Krafla Geothermal Power Station Timeline:
1974 - The first trial boreholes are drilled
1975 - Beginning of seismic and volcanic impacts threaten continued development of the plant
1975 - Sinking production wells and construction of power plant despite seismic activity
1977 - Power Plant begins operation
1978 - Plant begins power production
1984 - Significant decline in seismic and volcanic impacts
1996 - Installed 2nd steam turbine and beginning of additional drilling
1999 - Producing 60MW (planned capacity)
In total, 33 boreholes were drilled, including 17 high pressure production wells and 5 low-pressure production wells. The plant uses 110kg/second of 7.7 bar saturated high-pressure steam and 36 kg/sec of 2.2 bar saturated low-pressure steam and has been in operation at 60MW since 1999.
Mannvit's involvement in the Krafla geothermal power plant started in 1994 and lasted until 2002 and revolved mainly around the development of the second phase of the project.
- Feasibility report
- Site lay-out planning
- Conceptual design
- Detailed mechanical design
- Environmental impact study and report
- Modeling of groundwater flow and transportation of contaminants
- Project management
- Overall plant design
- Detailed design of HVAC systems
- Bid preparation and tender evaluation
- Site supervision
Olkaria II Power Station is currently Africa’ s largest Geothermal Power Station. It is currently generating 70 MWe and is the second geothermal plant that is operated by KenGen. The power plant was commissioned in November 2003.
Olkaria II Geothermal Power Plant is located in the North Eastern Sector of the greater Olkaria geothermal field. Wells were drilled between 1986 and 1993 but construction of the power plant was delayed until the year 2000 when funds became available.
The project was co-financed by the World Bank, the European Investment Bank, KfW of Germany and the Kenyan Government. Designed and constructed with an advantage of newer technology, this state-of-the-art plant is highly efficient in steam utilization.
Olkaria II Geothermal Power Plant operates on a single flash plant cycle with a steam consumption of 7.5 tonnes per hour per megawatt generated. The turbines are single flow six-stage condensing with direct contact spray jet condenser. The Power generated is transmitted to the national grid via 220 kV double circuit line to Nairobi. Olkaria II power station is also connected to Olkaria I Power Station by a 132 kV line.
The Svartsengi Geothermal Power Plant is a geothermal power station located in Keflavik, Iceland, near the Keflavík International Airport at the Reykjanes Peninsula. As of December 2007, it produces 76.5 MW of energy, and about 475 litres/second of 90 °C (194 °F) hot water (ca. 80 MW). Surplus mineral rich water from the plant fills up the Blue Lagoon, a tourist bathing resort.
|Svartsengi Power Station|
The Blue Lagoon with the power station in the background.
|Location||Keflavik, Iceland |
|Installed capacity||76.5 MW|
The Kawerau Geothermal Power Plant is a 100-megawatt geothermal power plant located just outside the town of Kawerau in the Bay of Plenty region of New Zealand. The power station is situated within the Kawerau geothermal field, which is part of the Taupo Volcanic Zone. Completed in July 2008 by Mighty River Power at a cost NZ$300 million, the plant's capacity proved greater than expected. The station is the largest single generator geothermal plant in New Zealand.
The Kawerau Geothermal Power Plant boosted the country's geothermal capacity by 25 percent and significantly increased local generation capacity in the Eastern Bay of Plenty. The plant meets approximately one third of residential and industrial demand in the region and provides cost certainty to local industry including Norske Skog Tasman.
The Kawerau Geothermal Power Plant uses a single Fuji turbine and steam from geothermal bores. The two phase fluid is flashed/separated twice to produce high and low pressure steam to feed the turbine.
The Kawerau Geothermal Power Plant field also supplies process steam to the Kawerau pulp and paper mill. This is used for process and power generation. Two small binary power plants use waste hot geothermal water for power generation.
A binary plant is also located west of the main power station. This station uses two phase fluid from one production well, KA24.
|Kawerau Power Station|
|Location||Bay of Plenty|
|Owner||Mighty River Power|
|Maximum capacity||100 MW|
The Centennial Drive Binary Geothermal Power Plant is a 23 MW binary cycle geothermal power station situated near Taupo, New Zealand. The power station is operated by Contact Energy.
In July 2008, Contact Energy announced that the contract for supply and construction of the binary cycle equipment was awarded to Ormat Technologies.
The Centennial Drive Binary Geothermal Power Plant is powered with steam and fluid from the Tauhara steamfield, and all used geothermal fluid is reinjected back into the edge of the steamfield.The Tauhara One plant was opened in May 2010, three weeks ahead of schedule.
|Centennial Drive Binary|
|Location||Centennial Drive, opposite Rakaunui Road, Taupo, New Zealand|
|Maximum capacity||23 MW|
The Ohaaki Power Station is a geothermal power plant owned and operated by Contact Energy. A distinctive feature of this power station is the 105 m high natural draft cooling tower, the only one of its kind in New Zealand.
Although initially constructed to generate 104 MW, decline in the steamfield has meant maximum net capacity is about 65 MW with an annual output of around 400 GWh pa.
There are currently three turbines in operation. One smaller turbine runs off high pressure steam which then backfeeds into the main intermediate pressure system that feeds the two main units. Condensers on the back end of the main turbines are fed cooled water from the cooling tower to condense the steam back into water. Additional condensate gained in this process is reinjected back into the ground.
The Ohaaki geothermal power plant is located adjacent to the Ohaaki Marae (Ngāti Tahu) on the banks of the Waikato River in New Zealand. Gradual sinking of the marae has been attributed to draw-off of geothermal fluids by the power station. The area of the marae is sinking approximately 170mm a year. In the 1960s, the marae was moved to its present location because the previous site was flooded when the dam for the Ohakuri Power Station was filled.
|Ohaaki Power Station|
|Maximum capacity||104 MW|
The Nesjavellir Geothermal Power Station is the second largest geothermal power plant in Iceland. The facility is located 177 m (581 ft) above sea level in the southwestern part of the country, near Thingvellir and the Hengill Volcano.
Plans for utilizing the Nesjavellir area for geothermal power and water heating began in 1947, when some boreholes were drilled to evaluate the area's potential for power generation. Research continued from 1965 to 1986. In 1987, the construction of the plant began, and the cornerstone was laid in May 1990. The station produces approximately 120MW of electrical power, and delivers around 1,800 litres (480 US gal) of hot water per second, servicing the hot water needs of the Greater Reykjavík Area.
|Nesjavellir Geothermal Power Station|
Nesjavellir Geothermal Power Station
|Location||Thingvellir, Iceland |
|Installed capacity||120 MW|
Nga Awa Purua is a geothermal power plant located near Taupo in New Zealand. The project was developed by Mighty River Power. Nga Awa Purua is New Zealand's second largest geothermal power station and the steam turbine is the largest geothermal turbine in the world.
The geothermal power plant is a joint venture between Mighty River Power and the Tauhara North No 2 Trust. The $430 million project first generated electricity on 18 January, and was officially opened by Prime Minister John Key on 15 May 2010.
The Rotokawa Power Station is situated close by.
|Nga Awa Purua|
|Owner||Mighty River Power|
|Maximum capacity||140 MW|
The pioneering Reykjanes Geothermal Power Plant in Iceland is now producing 100MWe from two 50MWe turbines. The plant uses steam from a reservoir at 290 to 320°C – the first time that geothermal steam of such high temperature has been used to generate electricity on a large scale.
The new plant is located on the Reykjanes peninsula, in the south-western corner of Iceland. Owned by Sudurnes Regional Heating Corporation, the plant was designed by Enex, a conglomerate from the Icelandic energy sector with wide experience in developing geothermal energy and hydropower. The two turbines started operation in May 2006 after testing and were formally brought on-line in December 2006.
HIGHEST TEMPERATURE YET FOR GEOTHERMAL STEAM
The Reykjanes plant uses steam and geothermal brine extracted from twelve 2,700m-deep wells. After extraction, the brine is piped into a steam separator. From there, the separated steam passes under 19 bars of pressure to a steam dryer and into the two 50MW turbines.
The plant is situated close to the ocean front, so seawater (4,000l/s) at 8°C can be pumped through a condenser for cooling and condensing the brine.
NEARLY 20% OF ICELAND'S ELECTRICITY FROM GEOTHERMAL
Geothermal resources have been used for over 70 years in Iceland. The geothermal area at Reykjanes is located on top of the Mid-Atlantic Ridge, formed by plate tectonics that are moving in separate directions. That gives high geothermal energy, with the Reykjanes area being where the plate boundary of the Reykjanes Ridge comes on land. The area is about 2km2 in size. Energy has been extracted from the area for around 30 years without significantly reducing the geothermal reserves.
Geothermal power plants produce nearly 20% of the country's electricity; geothermal heating also supplies nearly 90% of the country's domestic heating and hot water requirements. Nearly all the rest comes from hydroelectric generation, with less than 0.1% from fossil fuels.
Geothermal brine cannot be used directly for heating because of its high mineral content. On cooling, it releases great quantities of hard deposits (silica) which block pipes and other equipment. The high temperature and salt content of the water therefore demands heat exchangers.
|Reykjanes Power Station|
Reykjanes Power Station
|Location||Reykjanes, Iceland |
|Installed capacity||100 MW|
|Maximum capacity||150 MW|
Low-potential sources of geothermal power were founded in Garni, Arzni,Jermuk, Ankavan and Sisian. The geothermal power can be utilizedfor heat-supply, heating of hothouses, residential buildings and industrial enterprises.
"Ameria" CJSC was contracted by World Bank Energy Invest PIU to develop a detailed feasibility study for the construction of "Jermaghbyur" geothermal power plant in Syunik Marz of the Republic of Armenia. The study was carried out in the scope of the process aimed at diversifying energy resources in Armenia and achieving a higher level of independence from the importing energy sources. The document, elaborated by Ameria consultants, proved the strategic importance and effectiveness of utilizing geothermal energy in Armenia, as well as the investment attractiveness of the overall project. Geothermal energy is considered as an effective resource for heat supply and generation of electric power. Today geothermal plants with the total heat production capacity of 12000 MW operate in more than 30 countries. The geothermal plants generate also electric power with the total capacity of 8000 MW. The share of geothermal energy in the world installed capacities is 0.4%.
"Jemaghbyur" station, which commissioned in 2008-2009, is a unique project. It does not have any analogues in the region and will positively differ from the majority of other energy generation capacities, especially in its renewability of resources, independence of importing energy sources, as well as in the minimal environmental impact.
The feasibility study of the project has indicated that the station based on 6 direct wells with the depth of up to 2.5 km each can have a capacity up to 25 MW and generate up to 195 mln KW/hour electric power a year.
Ameria is a group of professional services companies registered in Armenia with the objective to provide a comprehensive package of professional advisory and assurance services. Ameria specializes in four major areas of professional activities: management advisory services; assurance and advisory services; legal advisory services; investment banking. Established in 1998, the company has become a leader in the Armenian market of advisory services bringing an
international reach and local touch to complex issues rising in more than 30 industry sectors.
The geothermal power plant was built in 1958, the first of its type in the world, and it is now being operated by Contact Energy. A binary cycle power plant was constructed in 2005 to use lower-temperature steam that had already gone through the main plant. This increased the total capacity of the power station to 181MW. The Wairakei power station is due to be phased out from 2011, replaced by the Te Mihi geothermal power station. The Poihipi Power Station was built in 1996 at a nearby site in the same field.
The use of steam from the field has had a number of visible effects on the local environment. Visible geothermal activity has increased (due to changes in the water table / water pressure allowing more steam to be created underground, upsurging at places like Craters of the Moon), while there has also been some land subsidence and reduction in steam volumes from the field after some decades of use. So far, total electrical production has been sustained or increased, with the investment in additional power stations such as the binary plant of 2005 designed for lower-temperature generation. Some power stations in the field are now capped in their extraction capacities and a substantial part of the water / steam is being reinjected after use.The hot geothermal fluid that is extracted is originally cold rainwater that had percolated downwards and been heated by hot rock; pumping back the warm water that emerges from the exhaust of the generator system thus reduces the heat drawn from the ground. Also, the Waikato river water is already too high in arsenic content to be safe to drink without special treatment, and so reinjection of the facility's water does not exacerbate this problem.
|Wairakei Power Station|
The Wairakei Power Station, with the main two blocks at the left rear. The binary plant is in front.
|Decommissioned||2011 onwards (planned)|
|Wayang Windu Geothermal Power Station|
|Turbines||1 × 110MW |
1 × 117MW
|Installed capacity||227 MW|
Construction of Wayang Windu Unit II Geothermal Power Plant Inaugurated
The construction of geothermal power plant (PLTP) Wayang Windu Unit II officially inaugurated by Minister of Energy and Mineral resources, in Pangalengan, Bandung, in Saturday (26/8). The construction of this 110 MW power plant is expected to be completed in 2008 and will improve the security of power supply in the region.
According to Minister Purnomo, the reliability of power supply system in Java-Bali system is now improved following the construction of some new power plants in West Java including the Wayang Windu Unit II as well as the completion of the construction of 500 KV transmission southern line, stretching from Tasikmalaya in West Java to Jakarta. Minister Purnomo also added that the construction of Wayang Windu Unit II will be followed by the Wayang Windu Unit III with the same capacity of 110 MW. “The development of geothermal power plant will improve the security of power supply for West Java region” said Minister Purnomo.
Electricity production with two 40 MW and 45 MW turbines commenced in 2006. In 2007, an additional steam turbine of 30 MW was added. In 2008, two 40 MW and 45 MW turbines were added with steam from Skarðsmýrarfjall Mountain. The hot water plant will be introduced in 2010.
|Installed capacity||213 MW (February 2009)|
|Maximum capacity||400 MW|
Cerro Prieto I
The CP1 powerhouse has a total installed capacity of 180 MW, generated by four units of 37.5 MW and one unit of 30 MW. Units 1 and 2 of this powerhouse was commissioned between 1973, followed by 3 and 4 in 1981.
Cerro Prieto II
The CP2 powerhouse has a total installed capacity of 220 MW, generated by two 110 MW units which were commissioned in 1982.
Cerro Prieto III
The CP3 powerhouse has a total installed capacity of 220 MW, generated by two identical units as CP2, measuring 110 MW. This powerhouse was commissioned in 1983, a year after the commissioning of CP2.
Cerro Prieto IV
The CP4 station commenced operations in July 2000, and consists of four turbines, each with a capacity of 25 MW.
Cerro Prieto V
The CP5 station is the newest powerhouse of the Cerro Prieto station. It was proposed in July 2009, with the commencement of constructions in September 2009. CP5 will consist of two 50 MW units, increasing the total capacity of the Cerro Prieto Geothermal Power Station by 100 MW.
|Cerro Prieto Geothermal Power Station||Mexico||720|
|Hellisheidi Power Station||Iceland||400|
|Inyo Power Station||United States||272|
|Wayang Windu Geothermal Power Station||Indonesia||227|
|Salton Sea Power Station||United States||185|
|Wairakei Power Station||New Zealand||181|
|Calistoga Power Station||United States||176|
|Jermaghbyur Geothermal Power Plant||Armenia||150|
|Reykjanes Power Station||Iceland||150|
|Nga Awa Purua Power Station||New Zealand||132|
|Nesjavellir Geothermal Power Station||Iceland||120|
|Ohaaki Power Station||New Zealand||104|
|Centennial Drive Binary Plant||New Zealand||100|
|Kawerau Power Station||New Zealand||100|
|Svartsengi Geothermal Power||Iceland||77|
|Olkaria II Geothermal Power Plant||Kenya||70|
|Krafla Geothermal Power Station||Iceland||60|
|Serrazzano Power Station||Italy||60|
|Poihipi Power Station||New Zealand||55|
|Mutnovskaya Power Station||Russia||50|