What are the environmental advantages of a geothermal power plant over a coal-fired power plant State two advantages

What are the design features of the Mutnovskaya GeoPP

The disadvantages described above are devoid of a binary cycle. In this case, the geothermal water in the heat exchangers is heated by a relatively low-boiling coolant. The turbine spins up in a closed cycle. Result:

• emissions of harmful substances into the atmosphere are minimized;
• higher plant efficiency;
• the ability to use water temperatures below 100 ° C.

The principle of operation related to the binary block was proposed by the designers of the Mutnovskaya GeoPP (JSC Geoterm). The need for such a technical solution was dictated by the analysis of the operation of the Verkhne-Mutnovskaya GTPP. At the station, a large amount of separate with a temperature of 150°C (about 1000 tons per hour) was not used and was pumped back into the reservoir.

Rational use of excess heat will make it possible to obtain more than 13 MW of electricity without attracting additional resources for drilling geothermal wells and extracting heat carriers.

At present, the power plant of the MGES consists of two circuits. In the first working fluid is a geothermal coolant. From it, steam and a separator enter the expander. In the second circuit, an organic working fluid is used.

What are the operating principles of a hydrothermal station

How can heat inside the earth's crust be converted into electrical energy? The process is based on fairly simple steps. Water is pumped underground through a special injection well. A kind of underground pool is formed, which acts as a heat exchanger. The water in it heats up and turns into steam, which is fed through a production well to the turbine blades connected to the generator axis. With the external simplicity of the process, in practice, operational problems arise:

• geothermal water needs to be purified from dissolved gases that destroy pipes and negatively affect the environment;
• the high boiling point of water leads to the loss of part of the energy with condensate.

Therefore, engineers are developing new schemes, each station has its own design features.

Notes

1. ↑ Kirill Degtyarev. (unavailable link). Russian Geographical Society (October 24, 2011). Retrieved November 1, 2012.
2. , With. 18, 98.
3. , With. 16-17.
4. ↑
5. ↑
6. . Habrahabr (30.04.2018). Retrieved 3 September 2019.
7. L. A. Ogurechnikov. . №11 (31). Alternative Energy and Ecology (2005). Retrieved November 1, 2012.
8. . Energosvet magazine. Retrieved November 1, 2012.
9. V. A. Butuzov, G. V. Tomarov, V. Kh. Shetov. . magazine "Energy Saving" (No. 3 2008). Retrieved November 1, 2012.
10. VSN 56-87 "Geothermal heat and cold supply of residential and public buildings and structures"

Geothermal stations in Russia

Geothermal energy, along with other types of "green" energy, is steadily developing on the territory of our state. According to scientists, the internal energy of the planet is thousands of times greater than the amount of energy contained in natural reserves of traditional fuels (oil, gas).

In Russia, geothermal stations are successfully operating, these are:

Pauzhetskaya GeoPP

Located near the village of Pauzhetka on the Kamchatka Peninsula. Put into operation in 1966.
Specifications:

1. Electric power - 12.0 MW;
2. The annual volume of generated electrical energy is 124.0 million kWh;
3. Number of power units - 2.

Reconstruction works are underway, as a result of which the electric power will increase to 17.0 MW.

Verkhne-Mutnovskaya Pilot GeoPP

Located in the Kamchatka Territory. It was put into operation in 1999.
Specifications:

1. Electric power - 12.0 MW;
2. The annual volume of generated electrical energy is 63.0 million kWh;
3. Number of power units - 3.

Mutnovskaya GeoPP

The largest power plant of its kind. Located in the Kamchatka Territory. It was put into operation in 2003.
Specifications:

1. Electric power - 50.0 MW;
2. The annual volume of generated electrical energy is 350.0 million kWh;
3. Number of power units - 2.

Ocean GeoPP

Located in the Sakhalin region. Put into operation in 2007.
Specifications:

1. Electric power - 2.5 MW;
2. Number of power modules - 2.

Mendeleevskaya GeoTPP

Located on the island of Kunashir. Put into operation in 2000.

Specifications:

1. Electric power - 3.6 MW;
2. Thermal power - 17 Gcal / hour;
3. Number of power modules - 2.

The station is currently being upgraded, after which the capacity will be 7.4 MW.

What are the main advantages and disadvantages of geothermal energy

This method of obtaining energy has a number of obvious advantages.

1. GeoPPs do not need fuel, the reserves of which are limited.
2. All operating costs are reduced to the costs of regulated work on the planned replacement of components.
3. Do not require additional energy for technological needs. Additional equipment is fed from the extracted resources.
4. It is possible to desalinate sea water along the way (If the station is located on the sea coast)
5. Conditionally considered environmentally friendly. Because the bulk of the shortcomings is tied to the environmental friendliness of objects.

If you carefully look at the photos of the Mutnovskaya hydrothermal station, you will be surprised. No dirt and soot, neat clean hulls with puffs of white steam. But not everything is so wonderful. Geothermal power plants have their drawbacks.

1. When located near settlements, residents are worried about the noise produced by the enterprise.
2. Building the station itself is expensive. And this affects the cost of the final product.
3. It is difficult to predict in advance what will come out of the well in the deep layers: mineral water (not necessarily healing), oil or toxic gas. And these are public safety issues. Of course, it's great if geologists stumble upon a mineral layer while drilling. But this discovery can completely change the way of life of the population. Therefore, local authorities are reluctant to give permission even for survey work.
4. There are difficulties with choosing a location for the future GeoPP. After all, if the heat source loses its energy potential over time, the money will be wasted. In addition, soil failures are possible in the area of ​​the station.

In Russia

Mutnovskaya GeoPP

In the USSR, the first geothermal power plant was built in 1966 in Kamchatka, in the valley of the Pauzhetka River. Its power is 12 MW.

On December 29, 1999, the Verkhne-Mutnovskaya GeoPP was put into operation at the Mutnovsky thermal water deposit with an installed capacity of 12 MW (for 2004).

On April 10, 2003, the first stage of the Mutnovskaya GeoPP was put into operation, the installed capacity for 2007 is 50 MW, the planned capacity of the station is 80 MW, and the generation in 2007 is 360.687 million kWh. The station is fully automated.

2002 - the first start-up complex Mendeleevskaya GeoTPP with a capacity of 3.6 MW was put into operation as part of the Tuman-2A power module and station infrastructure.

2007 - commissioning of the Ocean GeoTPP, located at the foot of the Baransky volcano on Iturup Island in the Sakhalin Region, with a capacity of 2.5 MW. The name of this power plant is associated with close proximity to the Pacific Ocean. In 2013, an accident occurred at the station, in 2015 the station was finally closed.

GeoPP name	Installed capacity at the end of 2010, MW	Generation in 2010, mln kWh	Year of input of the first block	Year of entry of the last block	Owner	Location
Mutnovskaya	50,0	360.7 (2007)	2003	2003	OJSC "Geoterm"	Kamchatka Krai
Pauzhetskaya	12,0	42,544	1966	2006	OJSC "Geoterm"	Kamchatka Krai
Verkhne-Mutnovskaya	12,0	63.01 (2006)	1999	2000	OJSC "Geoterm"	Kamchatka Krai
Mendeleevskaya	3,6	?	2002	2007	CJSC Energia Yuzhno-Kurilskaya	O. Kunashir
Sum	77,6	>466,3

What is geothermal energy

According to geophysicists, the temperature of the Earth's core is between 3,000 and 6,000°C. It is believed that at the bottom of the earth's crust at a depth of 10-15 km, the temperature drops to 600-800°C, in the oceans only 150-200°C. But these temperatures are enough to do the job. The main sources of subsoil heating are uranium, thorium and radioactive potassium. Earthquakes, eruptions of hundreds of volcanoes, geysers testify to the power of internal energy.

Geothermal refers to the heat energy that is released from the interior of the Earth to the surface. It can be used in areas of seismic and volcanic activity. Where the heat of the earth rises in the form of hot water and steam, breaking out in gushing springs (geysers). Geothermal energy is effectively used in the following countries: Hungary, Iceland, Italy, Mexico, New Zealand, Russia, El Salvador, USA, Philippines, Japan. Geothermal sources are classified into emitting

• dry hot steam
• wet hot steam
• hot water.

According to experts, from 1993 to 2000, the production of electricity using geothermal energy has more than doubled in the world. In the western part of the United States, almost 200 houses and farms are heated by hot water from the bowels of the Earth. In Iceland, almost 80% of the housing stock is warmed by water extracted from geothermal wells near the town of Reykjavik.

Advantages and disadvantages

Advantages

The main advantage of geothermal energy is its practical inexhaustibility and complete independence from environmental conditions, time of day and year. The installed capacity utilization factor of GeoTPP can reach 80%, which is unattainable for any other alternative energy.

Economic feasibility of wells

In order to convert thermal energy into electrical energy using some kind of heat engine (for example, a steam turbine), it is necessary that the temperature of the geothermal waters be high enough, otherwise the efficiency of the heat engine will be too low (for example, at a water temperature of 40 ° C and ambient temperature of 20°C, the efficiency of an ideal heat engine will be only 6%, and the efficiency of real machines is even lower, in addition, part of the energy will be spent on the plant’s own needs, for example, on the operation of pumps that pump coolant out of the well and pump the spent coolant back ). To generate electricity, it is advisable to use geothermal water with a temperature of 150 ° C and above. Even for heating and hot water, a temperature of at least 50°C is required. However, the temperature of the Earth increases rather slowly with depth, usually the geothermal gradient is only 30°C per 1 km, i.e. even for hot water supply, a well more than a kilometer deep would be required, and for electricity generation, several kilometers. Drilling such deep wells is expensive, in addition, pumping the coolant through them also requires energy, so the use of geothermal energy is far from advisable everywhere. Almost all large GeoPPs are located in places of increased volcanism - Kamchatka, Iceland, the Philippines, Kenya, California, etc., where the geothermal gradient is much higher, and geothermal waters are close to the surface.

Heat carrier ecology

One of the problems that arise when using underground thermal waters is the need for a renewable cycle of inflow (injection) of water (usually exhausted) into the underground aquifer, which requires energy consumption. Thermal waters contain a large amount of salts of various toxic metals (for example, lead, zinc, cadmium), non-metals (for example, boron, arsenic) and chemical compounds (ammonia, phenols), which excludes the discharge of these waters into natural water systems located on the surface . The injection of waste water is also necessary so that the pressure in the aquifer does not fall, which will lead to a decrease in the production of a geothermal station or its complete inoperability.

Of greatest interest are high-temperature thermal waters or steam outlets that can be used for electricity generation and heat supply.

Provoking earthquakes

2017 Pohang earthquake

The economic feasibility of drilling and well infrastructure makes it necessary to choose locations with a large geothermal gradient. Such places are usually located in seismically active zones. In addition, during the construction of the GCC station, hydraulic stimulation of the rocks is carried out, which makes it possible to increase the heat transfer of the coolant with the rocks due to additional cracks. However, according to the results of the study of the 2017 Pohang earthquake (Korean, English), it turned out that even regulation using measurements from additional seismographic stations is not enough to exclude induced earthquakes. Provoked by the operation of a geothermal station, the Pohang earthquake occurred on November 15, 2017, with a magnitude of 5.4 units, 135 people were injured and 1,700 were left homeless.

How the Mutnovskaya GeoPP was built

And how are the possibilities of geothermal energy used in Russia? Back in the sixties of the last century, the main problem of the USSR was not a lack of resources, but the difficulty of delivering energy across vast territories. Soviet scientists proposed bold and unexpected projects: turning the northern rivers south, using the energy of sea tides and active volcanoes.

The first successful solution for the use of alternative energy was the construction of the Pauzhetskaya geothermal station in Kamchatka. Its capacity was enough to serve the nearby villages: Ozernovsky, Shumny, Pauzhetka and fish canning plants in the area. The energy sources were the Kambalny and Koshelev volcanoes.

Further more. In 1987, the Decree of the Central Committee of the CPSU “On the integrated development of the Far Eastern Economic Region” was issued. The document spells out the importance of Kamchatka's geothermal resources. A decision is made to build and put into operation by 1997 the Mutnovskaya GeoTPP with a capacity of 50,000 kW. It is planned to increase the station's capacity by 1998 to 200,000 kW.

The plans did not come true. The Soviet Union collapsed. In order to implement the project for the construction of a geothermal station in Kamchatka in 1994, Geoterm OJSC was created. The first phase of the Mutnovskaya GeoPP was put into operation only in 2001. After the launch of the second block in 2002, the station reached an operating capacity of 50 MW. To date, three stages of power units, five turbines have been put into operation, which allows the plant to operate stably and generate cheap electricity.

In total, about 90 wells have been drilled on the territory of MGES-1. To maintain capacity in 2008, a working well Geo-1 was put into operation. Together with the Verkhne-Mutnovskaya GTPP, the stations supply electricity to more than a third of the Kamchatka Territory.

Flaws

• flooding
  arable land

• building
  conducted only where there are large
  water energy reserves

• on the
  mountain rivers are dangerous because of the high
  seismicity of areas

• abbreviated
  and unregulated releases of water from
  reservoirs for 10-15 days (up to their
  absence), lead to the restructuring
  unique floodplain ecosystems
  throughout the riverbed, as a result, pollution
  rivers, reduction of food chains,
  decline in fish numbers, elimination
  invertebrate aquatic animals,
  increasing the aggressiveness of the components
  midges (midges) due to malnutrition on
  larval stages, disappearance of places
  breeding grounds for many species of migratory
  birds, insufficient moistening of the floodplain
  soils, negative plant successions
  (phytomass depletion), flux reduction
  nutrients into the oceans.

Sunny
power station —
engineering building serving
converting solar radiation into
electrical energy. Ways
conversion of solar radiation
are different and depend on the design
power plants

Where is the Mutnovskaya geothermal station

Mutnovskaya Sopka is a complex volcanic massif. Its height is 2323 m above sea level. On the slopes there are various forms of modern gas-hydrothermal activity. Here, at the foot of the volcano, 116 km from the city of Petropavlovsk-Kamchatsky, the Mutnovskaya GeoPP is located. According to geological exploration, there is a rich geothermal deposit here, its reserves are estimated at about 300 MW.

What mode does it work in?

A high level of automation allows the equipment to be operated by a minimum number of personnel. The control center maintains 24-hour monitoring of instruments that accurately indicate the quantity and quality of water, steam and energy output.

Employees work on a rotational basis. The change lasts 15 days. The road to the station lies through the Mutnovsky Pass, sometimes covered with snow even in July, so there are personnel delays for a couple of days on the way.

A comfortable hostel has been built for workers within a twenty-minute walk. There is a relaxation room, gym, library, sauna, swimming pool. Interesting facts about Mutnovskaya GeoPP

Why are the surroundings of Mutnovskaya Sopka attractive?

Kamchatka is a tourist paradise, the places are little traveled and insanely beautiful. The surroundings of Mutnovsky volcano are especially popular among tourists. Travelers are attracted here by a convenient location 120 km from Petropavlovsk-Kamchatsky and the road, surrounded by picturesque hills and volcanoes, dense forests and fast rivers. Several viewing platforms offer excellent views of the Vilyuchinskaya Sopka, the height of which is 2175 meters.

Local ground squirrels, torbagans, foxes scurry around here, and on the slopes of the hills, the outlines of brown bears are often visible. There are bears and along the banks of the rivers, they feast on fish!

Story

In 1817, Count François de Larderel developed a technology for collecting steam from natural geothermal sources.
In the 20th century, the demand for electricity led to the emergence of power plant projects that use the internal heat of the Earth.
The person who tested the first geothermal generator was Piero Ginori Conti. It happened on July 4, 1904 in the Italian city of Larderello. The generator was able to successfully light four electric light bulbs. Later, in 1911, the world's first geothermal power plant was built in the same village, and it is still in operation. In the 1920s, experimental generators were built in Beppu (Japan) and California geysers, but Italy was the world's only industrial producer of geothermal electricity until 1958.

Top five countries in geothermal energy production, 1980–2012 (US EIA)

GeoPP capacity growth by years

In 1958, when the Wairakei power plant was commissioned, New Zealand became the second major industrial producer of geothermal electricity. Wairakei was the first station of the indirect type. In 1960, Pacific Gas and Electric began operating the first successful geothermal power plant in the United States on geysers in California.
The first binary geothermal power plant was first demonstrated in 1967 in the Soviet Union and then introduced to the US in 1981, following the energy crisis of the 1970s and major changes in regulatory policy. This technology makes it possible to use a much lower temperature for electricity generation than before. In 2006, China Hot Springs, Alaska, launched a binary cycle plant producing electricity at a record low liquid temperature of 57°C.
Until recently, geothermal power plants were built exclusively where there were high-temperature geothermal sources near the surface. The advent of binary cycle power plants and improvements in drilling and production technology could lead to the emergence of geothermal power plants over a much wider geographic range.Demonstration power plants are located in the German city of Landau in der Pfalz and the French city of Soultz-sous-Foret, while earlier work in Basel, Switzerland, was shut down after it triggered earthquakes. Other demonstration projects are under development in Australia, the United Kingdom and the United States of America.

The thermal efficiency of geothermal power plants is low - about 7-10%, since geothermal fluids have a lower temperature than steam from boilers. According to the laws of thermodynamics, this low temperature limits the efficiency of heat engines in extracting usable energy to generate electricity. Waste heat is wasted unless it can be used directly, such as in greenhouses or district heating. System efficiency does not affect operating costs as it would for a coal or other fossil fuel plant, but it is a factor in plant viability. To produce more energy than the pumps consume, high-temperature geothermal sources and specialized thermal cycles are required to generate electricity. Since geothermal energy is constant over time, unlike, for example, wind or solar energy, its power factor can be quite large - up to 96%.