GEOTHERMAL ENERGY

BY:-ASHWITH B S 14030141ME012

WHAT IS GEOTHERMAL ENERGY ? Geothermal is the heat from the Earth. It is clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found few miles beneath the Earths surface, and down even deeper to the extremely high temperatures of molten rock called magma .

HISTORY OF GEOTHERMAL ENERGY The use of geothermal energy for heating

purpose is not new. Ancient people used it for heating and bathing

through hot springs. Using geothermal energy to produce electricity

is a new industry. A group of Italians first used it in 1911. The

Italians used the natural steam erupting from the earth to power a turbine generator.

First Geothermal power plant in Larderello, Italy 1911

GEOTHERMAL RESERVOIRS The rising hot water and steam trapped in permeable and porous rock to form a geothermal reservoir.Reservoirs can be discovered by :Testing the soil Analysing underground temperature

Geothermal reservoirs can be found in places where we find : Geyser Boiling mud pot Volcano Hot springs Steam vents

GEYSERA Geyser is a rare kind of hot spring that is under pressure and erupts, sending jet of water and steam into the air. Geysers are made from a tube like hole in the earths surface that runs deep into the crust . The tube is filled with water. As the water boils, the resulting pressure forces a superheated column of steam and water to the surface. Geysers are located near active volcanoes.

BOILING MUD POTMud pots form in high temperature geothermal areas where water is in short supply. The little water that is available rises to the surface at a spot where the soil is rich in volcanic ash, clay and other fine particulates. The thickness of the mud usually changes along with seasonal changes in the water table. Mud pots are hot springs which do not have much water. The water in a mud pot is very acidic and it dissolves nearby rock into small pieces of clay. This clay then mixes with the hot water to create mud. Hot steam rising from below causes the mud to bubble and pop as the steam is released into the air.

VOLCANOA volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging.

HOT SPRINGSA hot spring is a spring produced by the emergence of geothermally heated groundwater that rises from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.

• Space heating in homes• Desalination• Industrial processes• Food dehydration plants• Greenhouse heating• Agriculture(crop drying & milk

pasteurization)• resorts and pools• melting snow

Uses of geothermal energy Direct use

Electricity production• Flash steam power plant • Dry steam power plant • Binary cycle power plant

Flash steam power plant

Flash steam power plants use naturally occurring sources of underground hot water and steam. Water that is hotter than 182°c is pumped into a low pressure area. Some of the water flashes or evaporates rapidly into steam, and is funnelled out to power a turbine and generate electricity. Any remaining water can be flashed in a separate tank to extract more energy . Flash steam power plants are the most common type of geothermal power plants.

The volcanically active island nation of Iceland supplies nearly all its electrical needs through a series of flash steam geothermal power plants . The steam and excess warm water produced by the flash steam process heat icy sidewalks and parking lots in the frigid arctic winter.

The islands of the Philippines also sit over a tectonically active area, the “Ring of Fire” that rims the Pacific ocean. Government and industry in the Philippines have invested in flash steam power plants, and today the nation is second only to the US states in its use of geothermal energy. In fact, the largest single geothermal power plant is a flash steam facility in Maltibog, Philippines.

Dry steam power plant

Dry steam power plant take advantage of natural underground sources of steam. The steam is piped directly to a power plant, where it is used to fuel turbines and generate electricity . Dry steam is the oldest type of power plant to generate electricity using geothermal energy.

The first geothermal plant was constructed in Larderello, Italy, in 1911. Today, the dry steam power plants at Larderello continue to supply electricity to more than a million residents of the area.

There are only two known sources of underground steam in the us: Yellowstone national park in Wyoming and the geysers in California. Since Yellowstone is a protected area, the geysers is the only place where a dry stream power plant is in use. It is one of the largest geothermal energy complexes in the world, and provides about a fifth of all renewable energy in California.

Binary cycle power plant

Binary cycle power plants use a unique process to conserve water and generate heat. Water is heated underground to about 107º - 182ºc. The hot water is contained in a pipe, which cycles above the ground. The hot water heats a liquid organic compound that has a lower boiling point than water. The organic liquid creates steam, which flows through a turbine and powers a generator to create electricity. The only emission in this process steam. The water in the pipe is recycled back to the ground, to be re-heated by the Earth and provide heat for the organic compound again.

The Beowawe geothermal facility in the US state of Nevada uses the binary cycle to generate electricity. The organic compound used at the facility is an industrial refrigerant (tetrafluroethane). This refrigerant has a lower boiling point than water, meaning it is converted into gas at low temperatures. The gas fuels the turbines, which are connected to electrical generators.

HOT DRY ROCKS The simplest models have one injection well

and two production wells. Pressurized cold water is sent down the injection well where the hot rocks heat the water up. Then pressurized water of temperatures greater than 2000F is brought to the surface and passed near a liquid with a lower boiling temperature, such as an organic liquid like butane. The ensuing steam turns the turbines .Then, the cool water is again injected to be heated. This system does not produce any emissions. US geothermal industries are making plans to commercialize this new technology.

Global view of geothermal energy

Top 10 biggest geothermal power plants in the world • The Geysers Geothermal complex, California, United States of AmericaThe Geysers Geothermal complex located about 121 km north of San Fransisco, California, is comprised of18 power plants making it the biggest geothermal installation in the world. The complex has an installed capacity of 1517 MW and active production capacity of 900 MW.Calpine owns 15 power plants in the complex, with a combined net generating capacity of about 725MW, while two power plants are jointly owned by Northern California Power Agency and Silicon Valley Power, plus US Renewables Group, which owns the Bottle Rock Power Plant. Ram Power is constructing a new 26MW geothermal power plant at the complex.The complex covers an area of approximately 78km². Production from the geothermal field commenced in 1960 and reached its peak in the 1980s. The turbines suppliers for the power plants in the complex include Toshiba and Mitsubishi Steam.• Larderello Geothermal complex, ItalyLarderello Geothermal complex, comprising of 34 plants with a total net capacity of769MW, is the second biggest geothermal power plants in the world. The power produced from the geothermal field, located in Tuscany, Central Italy, accounts for ten percent of all geothermal energy produced worldwide and caters for 26.5% of regional power needs.Enel Green Power owns the power plants at the complex serving approximately two million families,8700 residential and business customers and 25 hecters of greenhouses. Reservoir depths at the geothermal field range 700m to 4000m below the surface. The first plant at the geothermal field was commissioned a century ago, in 1911 making it the first of its kind in the world

The first Larderello power plant had a generating capacity of 250kW comprising of a turbine designed and built by Tosi Electrochemical Company. The geothermal plants at the field were rebuilt after they were destroyed during World War ii.

• Cerro Prieto Geothermal Power Station, MexicoAt 720MW, Cerro Prieto Geothermal Power station in south Mexicali, Baja California in north Mexico, is the second third geothermal plant in the world.The power plant, like all other geothermal fields in Mexico, is owned and operated by the Commission Federal de Electricidad (CFE). The power station features four plants, comprising of 13 units . The first plant was commissioned in 1973, while fourth plant was commissioned in 2000.The turbines at the complex include four 110MW condensing type, four 110Mw double-flash type, four single-flash of 37.5MW each, four single-flash of 25MW each and one 30MW single-flash. They were supplied by Toshiba and Mitsubishi heavy industries. A fifth plant, which will comprise of two 50MW turbines I currently under construction.

• Makban Geothermal Complex, Philippines Makban Geothermal power complex, also known as Makiling-Banahaw power plants, is located in the municipalities of bay and Calauan in the Laguna province and Santo Tomas in the Batangas province. It is the fourth biggest geothermal power facility in the world with an output capacity of 458MW.The geothermal power complex is owned by AP Renewables a wholly- owned subsidiary of aboitiz power. The complex of six power plants comprising an area of 10 units including a binary plant with five 3MW units and one 0.73MW unit.

The complex covering an area of 700ha, commenced operations in 1979. Mitsubishi Heavy industries was one of the turbine suppliers for the plants at the complex.

• CalEnergy Generation’s Salton Sea Geothermal Plants, United StatesCalEnergy Generation’s Salton Sea Geothermal Plants include a cluster of 10 generating geothermal plants in Calipatria, near the Salton Sea in Southern California’s imperial Valley. With a combined generating capacity of 340MW, it is the fifth largest geothermal facility in the world.Unit 1 with an out put capacity of 10MW was the first to come in 1982. it was built by a joint venture comprising of Union Oil Company and Southern California Edison. The 10th field came online in 2000. CalEnergy generation is currently developing new projects in the area including the Black Rock Project which will consist of three new 50MW geothermal plants.

• Hellisheidi Geothermal Power Plant, IcelandHellisheidi geothermal power plant is a flash steam, combined heat and power plant(CHP) located at Mount Hengill, approximately 20kM east of the capital city of Reykjavik. The plant has production capacity of 303MW of electrical energy and 400MW of thermal energy.The sixth largest geothermal power plant is owned by Orkuveita Reykjavikur. It was constructed by Mannvit Engineering and Verkis Engineering. Power generated from the plant is supplied primarily to the nearby aluminium refineries.The power plant was commissioned in 5 phases from 2006-2011. it covers an area of approx. 13000m² . Six high pressure turbines for the plant were supplied by Mitsubishi, while a low pressure turbine was supplied by Toshiba.

• Tiwi Geothermal Complex, PhilippinesTiwi Geothermal Complex is located at Tiwi in the province of Albay, about 300kM south-east of Manila. The complex is the seventh biggest geothermal facility in the world.The Tiwi complex is owned by Aboitiz Power’s subsidiary AP renewables . It comprises of three power plants featuring two units each. Drilling works at the geothermal field commenced in 1972and the power plant became operational in 1979. The project was developed by national power corporation and Philippine Geothermal, Mitsui and F.F.Cruz were the construction contractors. The power plant use Toshiba generator units.

• Malitbog Geothermal Power Plant, IndonesiaThe 232.5MW Malitbog Geothermal power station located approximately 25kM north of Ormoc city in Leyte island is the 8th biggest geothermal power plant in the world. The plant was earlier owned by Visayas Geothermal Power Company which later transferred the ownership rights to Philippine National oil-Energy development Company. The plant is currently owned by Energy development Corporation. Power from the field is supplied to the Luzon Island.The Maltibog geothermal power plant construction commenced in 1993 and was completed in 1996. it was built by Sumitomo Corporation and Fuji Electric. The plant features three 77.5MW single-cylinder double flow condensing turbines supplied by Fuji electric.

• Wayang Windu Geothermal Power Plant, IndonesiaWayang Windu Geothermal Power Plant is located in Pangalengan, approximately 40kM south of Bandung City in the province of west Java. The plant with an output capacity of 227MW, is the 9th biggest in the world.Magma Nusantara Limited, a wholly-owned subsidiary of star Energy, operates the field. Engineering services for the 1st two units were provided by Acecom. Major contrators involved in the plants construction included Sumitomo corporation, Fuji Electric and Rekayasa industry.The 1st unit of the power plant started [operation in 2000. it is comprised of an 110MW turbine by fuji electric . The second unit featuring a 117MW turbine, was commissioned in 2009. the 3rd unit , with a generation capacity of 127MW, was expected to be commissioned in mid 2014.

• Darajat Power Station, IndonesiaDarajat power station is located at Garut in Pasirwangi District, west Java. It is the 10th biggest plant in the world, with an installed capacity of 259MW. It is managed by GPP Amoseas Indonesia, a subsidiary of Chevron Texaco. The power station comprises of 3 plants serving the provinces of Java and Bali. The plants were commissioned respectively in 1994, 2000 and 2007. Plants ii and iii share common facilities including the steam gathering system.The latest commissioned plant was built by Thiess Contractors Indonesia in collaboration with Kanematsu Corporation. It features a turbine supplied by Mitsubishi heavy industries. The turbine for the second plant was also supplied by MHI . Hyundai Engineering supplied the equipment's for the first two plants.

Existing capacity and new capacity in Turkey, 1984-2015,in MW

India has a huge potential to become a leading contributor in generating eco friendly and cost effective geothermal power. Around 6.5 percent of electricity generation in the world would be done with the help of geothermal energy in India and would have to play a bigger role in the coming years in this direction. In India studies for locating geothermal energy source were undertaken by the geological survey of India over the last three decades after which around 340 hot springs were traced . Chattisgharh government has decided to establish the first geothermal power plant of the country in the newly formed state Balrampur. State government has granted permission for the installation of geothermal power plant at Tattapani area of Balrampur district to the NTPC. The Tattapani geothermal field is the most promising geothermal resource in central India. The MoU(memorandum of understanding) was signed by director Shailendra Shukla and NTPC executive director Ajit Kumar in the presence of secretary energy Aman Singh regional executive director NTPC N Ganguly and MDs of electricity companies of Chattisgharh.NTPC has already started exploratory work in the area . It has also started talks with ONGC(Oil and Natural Gas Corp. Ltd) and other international organisations for drilling operation. Thus India has set a foot in producing green and renewable energy.

INDIA AND GEOTHERMAL ENERGY

Geothermal field Estimated reservoir temperature(approx.)

Puga geothermal field 240°c art 2000 meter

Tattapani Sarguja(Chattisgarh)

120°c-150°c at 500 meter and 200°c at 2000 meter

Tapoban Chamoli(Uttarkhand)

100°c at 430 meter

Cambay Garden(Gujarat)

160°c at 1900 meter

Badrinath Chamoli(Uttarkhand)

150°c

Surajkund Hazaribagh(Jharkhand)

110°c

ManikaranKullu (HP)

100°c

KasolKullu (HP)

110°c

Pros of Geothermal energy• Renewable: Geothermal energy is extracted from earths core and will be available as

long as earth exists. It is therefore renewable and can be used roughly 4-5 billion years.• Environment Friendly: Geothermal energy is green in all aspects of its production and

use, when it comes to the process of developing and making it, geothermal power is practically completely emission free. There is absolutely zero carbon used when it comes to the production of this type of power.

• No Fuel: no Fuel is used at all during the production and use of the energy. Because there is absolutely no mining or transportation related to the process, which means that there aren’t trucks emitting fumes and gas, which means that the atmosphere is not being affected by the process.

• Abundant Supply: with geothermal energy, there is no shortages or other sorts of problems that sometimes occur with other types of power. They are not subject to the same issues as solar or wind power, which means that you wont get a shortage because the weather isn’t cooperating with what you want. There is practically boundless supply.

• Significant Saving for Home Owners: there has been a tremendous increase in the number of homeowners who want to utilize geothermal energy for heating and cooling purposes. The results is that less energy is used for heating homes and offices which results in significant savings for home owners.

• Smallest Land Footprint: Geothermal energy extracts heat from hot water move the turbines that produce electricity. To extract energy, substantial amount of piping is required to be laid underground. Geothermal energy has the smallest land footprint of any major energy source in the world.

• Innovation in Technology: When it comes to green energy, geothermal energy is one of the first types that is being explored. New innovations are coming out for it all the time , which means that it will likely be easier to deal with some of the difficulties with the technology as time goes on. It can also be manufactured underground. New innovations that are coming out are basically guaranteed to be able to use lower temperatures in the future iterations of the technology as well.

• Suitable to Particular Region: Everything that deals with geothermal power seems to

be really far away from everything that is in and around the area. Prime destinations are exceptionally zone specific, so you cannot really find geothermal power outside of those areas. Also the prime destinations are frequently a long way from urban areas, which means they are virtually useless when it comes to cities and such.

• High Initial Costs: For those residential owners who are thinking to use geothermal energy, high upfront costs is something that turns out to be a huge setback to them. For an averaged sized home, installation of geothermal heat pumps costs between $10,000 - $20,000 .

• Surface Instability: Geothermal has become infamous for causing earthquakes as setting up of geothermal power plants can alter the lands structure. A process called hydraulic fracturing is an integral part for building a large scale and efficient geothermal system power plants that can trigger earthquakes.

• Environment concerns: There are some environmental concerns. Water use is one of the big concerns, because geothermal power uses a lot of water in its processes and such. There are also a number of different compounds that go into the water and ground as a result of the process, including so₂ and silica discharges, both of which can harm the environment if you are not careful about it.

• High temperatures Needed: The process is not exactly an easy one for you to execute, boring into warmed rock is extremely troublesome, in order for geothermal processes to begin, you also need the area in question to be at least 350°F, otherwise the process may not occur as you wish them to.

Cons of Geothermal Energy

Conclusion:-Obviously, Geothermal energy has a great potential as a clean, green and naturally occurring renewable source of energy. Geothermal hot water can be used for many application that require heat including heating buildings, rising plants in green houses, drying crops, heating water at fish farms, and several industrial process, it can be used for generating electricity as well. It is therefore necessary to explore the possibility of setting up more geothermal power plants to use the naturally occurring renewable source of energy.

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