Small hydropower. Small hydroelectric power plants - types and designs. Description of the work of hydroelectric power plants

Small hydropower

Description of the work of hydroelectric power plants

Hydroelectric power plants and living environment

Hydropower potential of Russia and its use

Pressure generation and main equipment of the HPP

HPP energy and capacity

Pumped storage power plants

Small hydroelectric power plants

Features of small hydropower plants

Advantages and disadvantages of small hydropower plants

Development regions and technological constraints

Recently, unconventional energy has received close attention all over the world. The interest in the use of renewable energy sources - sun, wind, river water and sea tide - is easy to explain: there is no need to purchase expensive fuel, it is possible to use small stations in order to provide hard-to-reach areas with electricity. This circumstance is especially important for countries where there are mountain ranges or sparsely populated areas where it is economically impractical to lay power grids.

Two thirds of the territory of Russia has no connection to the energy system

In Russia, the areas of decentralized energy supply cover 70% of the country's territory. We still have settlements where electricity has never been available. And these are not always settlements in Siberia or the Far North. Electrification has not reached, for example, some settlements in the Urals - these are regions that cannot be called unfavorable for the energy sector. In addition, electrification of hard-to-reach and remote settlements is not so difficult. In any corner of the country there is a stream or river where you can equip micro hydroelectric power plants.

Micro and small hydropower plants

Small hydropower facilities - small and micro hydropower plants. This area of \u200b\u200benergy production deals with the use of energy from water resources and hydraulic systems using hydropower plants of low power (1-3000 kW). In the world, small-scale energy has begun to develop in recent decades, this is mainly due to the desire to avoid environmental damage caused by the reservoirs of large hydroelectric power plants, with the ability to guarantee energy supply in isolated and hard-to-reach areas, as well as with low capital costs for the construction of plants and a quick return on investment ( up to 5 years).

Where can small hydropower facilities be installed?

The hydroelectric unit of a small hydroelectric power station (MHES) includes a generator, turbines and automatic control systems. According to the type of hydro resources used, the SHPPs are divided into categories: new run-of-river or dam stations with small reservoirs; stations operating at the expense of high-speed energy of the free flow of rivers; stations that use the existing water level differences in the flood water facilities - from water treatment complexes to shipping facilities (today there is experience in the use of drinking water pipelines, sewage and industrial effluents).

The use of the energy of small streams with the help of small hydroelectric power plants is one of the most effective directions for the development of renewable energy in our country. Most of the resources small hydropower in Russia they are concentrated in the Far East, in the North Caucasus, in the North-West (Murmansk, Arkhangelsk, Karelia, Kaliningrad), in Tuva, in Altai, in the Tyumen region and in Yakutia.

Micro hydroelectric power plants (power up to 100 kW) are installed almost anywhere. The hydraulic unit includes a water intake device, a power unit and an automatic control device. Micro hydroelectric power plants are used as sources of electricity for farms, summer cottages, farms and small industries in hard-to-reach areas - where it is unprofitable to lay networks.

Small hydropower is in demand only by 1%

The technical and economic capabilities of small hydropower in our country exceed the capabilities of the following renewable sources: sun, wind, biomass, and all of them combined. Today it is estimated at 60 billion kWh per year. But this potential is used poorly: only by 1%. In the 1950s and 1960s, several thousand small hydroelectric power plants operated. Today - only a few hundred - reflected the consequences of distortions in pricing policy and little attention to improving the quality and professionalism of equipment designs, to the use of advanced technologies and materials.

To the question of ecology

The main advantage of small hydropower is environmental safety. During the construction of facilities in this industry and their further operation, there are no harmful effects on the quality and properties of water. The reservoirs can be used both for fishery activities and as sources of water supply for the population. But besides this, small and micro hydroelectric power plants have many advantages. Modern stations have simple designs and are fully automated, i.e. they do not require human presence during operation.

The electric current generated by them meets the requirements of GOST in terms of voltage and frequency, and the stations are capable of operating autonomously, i.e. outside the power grid of the region or region, and as part of this power grid. The total service life of the station is over 40 years (at least 5 years before overhaul). And the main advantage is that small hydropower facilities do not require the organization of large reservoirs with a corresponding huge material damage and flooding of the territory.

About equipment manufacturing companies

In the 1990s, due to a decrease in the volume of large-scale construction in the domestic hydropower industry, our country partially reoriented production enterprises for the needs of small hydropower, here are some of them: Tyazhmash JSC (the city of Syzran), LMZ JSC and NPO CKTI JSC (the city of St. Petersburg), etc. At the same time, joint stock companies and small enterprises producing equipment for small hydroelectric power plants were formed, including within the framework of conversion. The most famous: NPTs "Rand" and JSC "MNTO Inset" from St. Petersburg, JSC "Energomash", JSC "NIIES" and JSC "Napor" from Moscow. Among the equipment suppliers, we will also note the regional organizations that were once part of the All-Union Institute "Hydroproject".

Today in the domestic market there are complete hydraulic units with automatic regulation and control systems for autonomous and network SHPPs for heads from 1 to 250 meters, as well as lifting, non-standard hydromechanical equipment, pressure pipelines, transformer substations, pre-turbine gates, switchgears and other components that are needed for the construction of small hydropower facilities. For SHPPs with the use of strategic pressure, hydraulic units with radial-axial, bucket, propeller, transverse and oblique-jet, frontal hydraulic turbines with a simplified design are used. Hydraulic turbines of the Wells, Darrieus, Savonius and others types are used for small HPPs with the use of high-speed pressure. Generators for small hydroelectric power plants are produced by JSC Privod (Lysva), JSC Electrosila (St. Petersburg), JSC SEGPO (Sarapul), JSC Ural-Electrotyazhmash, JSC SEZ (Safonovo), etc.

Nature has provided us with the most unpretentious method of obtaining energy. Alas, we practically do not use it. It remains to be hoped that in the future, with the development of small production, there will still be a need to use the energy of a huge number of natural reservoirs in Russia.

Small HPP "Chala"

In St. Petersburg, the Georgian small-scale HPP Chala was commissioned with a capacity of 1,500 kW (three hydraulic units of 500 kW each). This station has been under construction since 1994, and the first hydraulic units were shipped back in 1995-1996. But the completion of the construction on time was prevented by the lack of funds from the customer - the alcoholic beverages manufacturing plant (previously it was the Tears of Lozy plant, known on the domestic market). But the plant was needed not only by the plant: next to the small hydroelectric power station there is a village, where until recently there was no electricity.

The peculiarity of the station is that it operates hydraulic units with bucket turbines, which have not been produced in Russia for about 30 years. They are designed for high pressures of a relatively small amount of water, they should be used in high-mountainous regions: the republics of Kabardino-Balkaria, Transcaucasia, Chechnya, Dagestan, Karachay-Cherkessia. At the Chala SHPP (head 200 meters), 300 liters of water are enough to provide a power of 500 kW.

The plant used precision casting technology to produce turbine buckets. They were produced at the plant. Klimov in St. Petersburg.

Hydropower is the area of \u200b\u200bthe most developed energy on renewable resources today, using the energy of falling water, waves and tides.

The main directions of hydropower development: restoration of old SHPPs by overhaul and partial replacement of equipment; construction of new SHPPs on non-energy (complex) reservoirs, on industrial spillways; construction of damless hydroelectric power plants, which use the kinetic energy of a moving mass of water (flow). Such stations, with a capacity of up to 10 ... 25 kW, do not require large capital expenditures for construction, are environmentally friendly and convenient to use when supplying power to low-power consumers located on the banks of rivers, in the presence of elevation differences in small streams (sleeve hydroelectric power plants), etc. In the presence of water streams, it is also promising to use water rams for water supply purposes, as well as the use of water wheels and low-power turbines to drive compressors of heat pumps.

The source of hydropower is the converted energy of the Sun in the form of stored potential energy of water, which is then converted into mechanical work and electricity.

Indeed, under the influence of solar radiation, water evaporates from the surface of lakes, rivers, seas and oceans. The vapor rises to the upper atmosphere, forming clouds; then it, condensing, falls out in the form of rain, replenishing water supplies in reservoirs.

The transformation of the potential energy of water into electrical energy takes place at a hydroelectric power plant. Maintaining a constant pressure is carried out with the help of platinum, which forms a reservoir that serves as a hydropower accumulator. In this regard, during the construction of a hydroelectric power station, certain requirements are imposed on the terrain, which should make it possible to organize a reservoir and create the required pressure from the dam. All this is associated with significant costs, and the cost of construction work can exceed the cost of equipment for the hydroelectric power station. At the same time, the unit cost of electricity generated by a hydroelectric power station is the lowest compared to the cost of energy produced by other sources. As a rule, the payback period for small hydropower plants does not exceed 10 years.

Fig. 1. Machine station with a hydraulic turbine

Hydraulic turbines are used to convert water energy into mechanical work (Fig. 1).

Distinguish between active and jet turbines.

In an active turbine, the kinetic energy of the flow is converted into mechanical energy. Additional devices for the operation of the turbine are a water conduit and a nozzle. A jet with kinetic energy emerges from the nozzle and is directed to the turbine blades in the air. The force acting on the blades from the side of the jet drives the turbine wheel into rotation, with the shaft of which the electric generator is coupled directly or through the drive. The efficiency of real turbines ranges from 50 to 90%. In water turbines of low power, the efficiency is lower.

The maximum efficiency is 100%. It can be achieved if the jet, after interacting with the blades, moves vertically downward only under the action of gravity.

The efficiency of an active hydraulic turbine can be increased due to a limited increase in the number of nozzles, since with a large number of them, the mutual influence of the jets will affect.

In a jet turbine, the impeller is completely immersed in the flow, which constantly acts on the turbine blades. In the most common Francis turbine, the rotation of the wheel is carried out due to the pressure difference between the flow at the inlet and at the outlet, water enters the impeller radially. The gap between the impeller and the chamber is variable. After the interaction of the stream with the wheel, it turns 90 °. Variable clearance and flow rotation improve turbine efficiency.

There are other design solutions for jet turbines, for example, the Kaplan propeller turbine. However, this type of turbine is less common due to the pressure drop.

HPPs come in a wide variety of capacities - from 3 kW to 12 GW. Small HPPs (also referred to as micro-HPPs and rural HPPs) are HPPs with an installed capacity of less than 500 kW. Their construction is usually carried out as an integral part of the complex, which also provides for the development of agricultural production, water supply and flow regulation.

Speaking about hydroelectric power plants, it should be noted that no other separate engineering structures have such a strong impact on nature as large reservoirs.

The reservoir supplies water not only to people, but also to the entire flora and fauna, which actively responds to new favorable conditions. This contributes to the emergence of new biological communities, the development of which was previously hindered by the lack of water (which is especially evident in small ponds arranged for the development of fisheries).

However, in an objective assessment of changes in environmental conditions, one cannot ignore some negative biochemical and limnological factors.

As is known, oxygen exchange in stagnant water of reservoirs occurs much slower than in watercourses (rivers and streams). Getting into such water, chemical impurities can create such an unfavorable stratigraphy in it (i.e., form stable layers of various compositions) that biological life will become impossible, fish and many other aquatic organisms will die. And when such poisoned water is released into the river, fish may die in the entire watercourse.

Dangerous for the reservoir and algae, which change the chemical composition of the water. The processes of decay in water bodies of industrial areas are especially harmful and environmentally unfavorable.

In general, it can be considered that the reservoirs have an ecologically beneficial effect on the environment, and the negative factors are primarily due to the discharge of industrial waste and (to a lesser extent) the irresponsible behavior of a very large number of tourists and vacationers. As for the direct technological process of generating electricity at hydroelectric power plants, from the point of view of ecology, it is completely safe. The construction of hydropower facilities should be designed with minimal damage to the environment.

When developing construction planning plans, it is necessary to rationally choose careers, the location of roads, etc. By the time the construction is completed, the necessary work should be carried out to recultivate the disturbance of the land and landscaping the territory.

The most effective environmental protection measure for the reservoir is engineering protection. For example, the construction of embankment dams reduces the flooded area and preserves land and mineral deposits for economic use, reduces the area of \u200b\u200bshallow waters and improves the sanitary conditions of the reservoir, preserves natural natural complexes.

If the construction of dams is not economically justified, then shallow waters can be used for breeding birds and for other economic needs. If the required water levels are maintained, shallow waters can be used for fisheries, as a spawning ground and food base.

To prevent or reduce the processing of banks, bank protection is performed. Enterprises, railways, residential and communal buildings, antiquities are removed from the flood zone.

To ensure high water quality, it is necessary to sanitize the reservoir bed before it is flooded with water. For this purpose, agrotechnical measures are taken to reduce polluted surface runoff and treatment facilities are being built.

The construction of large dams with power plants, as a rule, contributes to the conservation and enrichment of nature. Artificial lakes allow the complex use of water resources. The water not only powers the turbines, but also irrigates the vast surrounding land and thus ensures the development of agriculture. Reservoirs soften the sharp contrasts of weather and climate, help fight drought, and thousands of people rest on their shores.

Small hydroelectric power plants were built and successfully operated in specific northern conditions since the end of the 19th century. Since the 1940s, the construction of small and mini-hydroelectric power plants (SHPPs) has been widely practiced in Russia. The lack of sufficient generating capacities in centralized energy systems, as well as the high cost of connecting to them, made the option of building and operating a small HPP quite cost-effective. They basically operated as independent energy producers, isolated from large power systems. By 1959, the number of SHPPs was about 5 thousand, and their total capacity reached 482 MW. In the Krasnoyarsk Territory in 1961, in the Severo-Yenisei region on the river. Enashimo put into operation the Enashiminskaya HPP with a capacity of 5500 kW.

Expansion of the construction of large power plants concurrently with the intensive construction of power lines in the 1960s - 1970s. made the operation of mini-hydroelectric power station unprofitable due to the lack of modern automatic regulation and control systems, as well as the lack of qualified specialists.

Recently, work on the design and construction of small and micro hydropower plants has been resumed in the country.

On the territory of Russia, even in the regions of developed EPS, there are a significant number of small isolated consumers, the power supply of which is carried out from autonomous sources. This category includes remote rural settlements, mining fields, settlements of pastoralists, hunters and fishermen, farms, as well as other small consumers located in hard-to-reach and remote areas. For these areas, it is advisable to use small hydroelectric power plants.

Small HPPs can be implemented as low-pressure and free-flow stations. Free-flow micro hydroelectric power plants of submersible and floating type with a capacity of up to 100 kW have the minimum cost of manufacturing, installation and operation. Submersible micro hydroelectric power plants of year-round operation are convenient for small settlements, farms. They can be used independently or in parallel with diesel power plants. Floating installations can be used in the summer in a party of prospectors, on pastures, etc.

In the conditions of Siberia, a large number of small rivers with the necessary supply of water resources makes it possible to quite economically solve the problem of power supply to low-power consumers.

The choice of the optimal design of a small hydroelectric power plant is a complex task, including the choice of the design parameters of the watercourse and the capacity of one module, the design of the turbine and generator, and the layout of the entire power plant. The use of float micro-hydroelectric power plants is cheaper, the design itself is much simpler. Its disadvantage is the seasonality of work, the requirement for the absence of timber rafting on the river.

Micro HPP with a capacity of 16 kW has been produced by the Tyazhelectromash plant in Bishkek since 1988. The design study of the station, including the hydro turbine, was carried out by the Design and Technological Institute (PKTI) Vodoavtomatika i metrologiya Bishkek.

The autoballast-type voltage and frequency stabilization system was developed in Tomsk and brought to serial production as a result of joint efforts of TPU and PKTI "Vodoavtomatika i metrologiya".

At the Siberian Federal University, under the leadership of professors A.L. Vstovsky and M.P. Golovin, draft designs of end-face synchronous generators with excitation from permanent magnets have been developed, which have a rotation frequency of 75 rpm to 1500 rpm and allow them to be used in installations without a multiplier (the mass and dimensions of these generators are 35 - 40% lower in comparison with the mass-produced ones, taking into account the multiplier mass, and their cost will also be lower in conditions of well-functioning serial production). The speed of the current, the depth and width of some rivers in Siberia, where it is possible to install floating free-flow micro-hydroelectric power plants with a capacity of up to 50 kW in a module, have been determined.

The design of a micro hydroelectric power station developed in SibFU based on an end-face generator driven by an orthogonal turbine made it possible to create an autonomous power supply source, which in terms of quantitative and qualitative indicators has no analogues in world practice. The design of an autonomous power plant, due to the use of the proposed generator in it, is transportable, has a relatively small size and weight, a simplified installation and operation scheme. No specialized equipment is required in the manufacture of the generator.

With the help of hydraulic turbines of various capacities installed on permanent watercourses (most often in river beds). As a rule, the creation of a hydroelectric power plant requires the construction of a dam, in which hydro turbines are installed, but it is also possible to create a damless hydroelectric power plant.

We will consider the possibilities of energy production using small hydropower plants and micro-hydropower plants (SHPPs). In Russian practice, micro-hydroelectric power plants mean plants with a capacity of up to 100 kW, and small ones - with a total installed capacity of up to 30 MW with a single hydroelectric unit capacity of up to 10 MW and a turbine impeller diameter of up to 3 m.

According to experts, such a classification makes it difficult to calculate the gross energy potential of small hydropower, since it does not allow determining the technical parameters of the hydroelectric power plant. At the same time, the gross potential of the EIA is understood as its average annual volume contained in a given resource, with its complete transformation into useful energy. Attention should be paid to this problem, since all calculations of the potential of renewable energy resources are based on models and methods that determine the accuracy of the final result, and therefore the effectiveness of using a particular energy resource in specific conditions.

In the most complete work on the assessment of hydropower resources in the USSR, published in 1967, the category of small hydroelectric power plants included all hydroelectric power plants created on flat rivers with a gross potential of up to 2.0 MW and mountain ones up to 1.7 MW. These classification features are considered optimal because they do not relate to the technical parameters of future HPPs.

In most cases, it is assumed that SHPPs are installed on small rivers and watercourses. Although small rivers are one of the most common types of water bodies, there is currently no unified approach to their definition. Various criteria are applied when defining the concept of a small river (small watercourse).

First of all, quantitative criteria are used. In accordance with GOST 17.1.1.02-77; near a small river, the catchment area does not exceed 2000 km2, and the average long-term runoff during the low-water period (minimum water level I) does not exceed 5 m3 / s. At the same time, according to another taxonomy, the catchment area of \u200b\u200ba small river should not exceed 200 km2, and its length should not exceed 100 km. There are also examples of how the classification takes into account the possibility of economic use of small rivers. But there is no unified, generally accepted approach to defining the concept of "small river" in Russia.

Advantages and disadvantages of small hydropower

Like any other method of energy production, the use of small and mini-hydroelectric power plants has both advantages and disadvantages.

The economic, environmental and social benefits of small hydropower facilities include the following. Their creation increases the energy security of the region, ensures independence from fuel suppliers located in other regions, and saves scarce fossil fuel. The construction of such an energy facility does not require large capital investments, a large amount of energy-intensive building materials and significant labor costs, and it pays off relatively quickly. In addition, there are opportunities to reduce the cost of construction through the unification and certification of equipment.

In the process of generating electricity, the HPP does not produce greenhouse gases and does not pollute the environment with combustion products and toxic waste, which meets the requirements of the Kyoto Protocol. Such objects are not the cause of induced seismicity and are relatively safe in case of natural occurrence of earthquakes. They do not have a negative impact on the lifestyle of the population, on the fauna and local microclimatic conditions.

Possible problems associated with the creation and use of small hydropower facilities are less pronounced, but they should also be mentioned.

Like any localized source of energy, in the case of an isolated application, a small hydropower facility is vulnerable from the point of view of failure, as a result of which consumers are left without power supply (the solution to the problem is the creation of joint or reserve generating capacities - a wind turbine, a cogeneration mini-boiler house on biofuel, photovoltaic installation, etc.).

The most common type of accidents at small hydropower facilities is the destruction of a dam and hydroelectric units as a result of an overflow over the crest of the dam with an unexpected rise in the water level and failure of shut-off devices. In some cases, SHPPs contribute to the silting up of reservoirs and influence the channel-forming processes.

There is a certain seasonality in electricity generation (noticeable recessions in winter and summer), which leads to the fact that in some regions small hydropower is considered as a reserve (duplicate) generating capacity.

Among the factors hindering the development of small hydropower in Russia, most experts say that potential users are not fully informed about the benefits of using small hydropower facilities; insufficient knowledge of the hydrological regime and flow volumes of small streams; low quality of existing methods, recommendations and SNiPs, which is the reason for serious errors in calculations; undeveloped methods for assessing and predicting possible impact on the environment and economic activity; a weak production and repair base of enterprises producing hydropower equipment for small hydropower plants, and the mass construction of small hydropower facilities is possible only in the case of serial production of equipment, refusal of individual design and a qualitatively new approach to the reliability and cost of equipment - in comparison with old facilities decommissioned ...

Hydropotential of Russia, its use

According to estimates made in the early 1960s, the USSR possessed 11.4% of the world's hydropower resources. The average annual capacity of the water resources of the former USSR was estimated at 434 million kWh (3.800 billion kWh of energy output per year). Calculations showed that it is technically possible and economically feasible to receive about 1.700 billion kWh of electricity, which is more than 5 times higher than the generation of all power plants in the country at that time.

The main part of this hydropower (74%) was located in the territory of the Russian Federation. The average annual potential capacity of Russia's hydro resources was estimated at 320 million kWh (production - 2.800 billion kWh per year), of which the generation of more than 1.340 billion kWh was technically possible at that time.

Table 1 Characteristics of some SHPPs operating in Russia
Location / destination	Year of creation		Installed power (kW)	Number of units	general power
Kirov region / agricultural farm		micro-hydroelectric power station-10
Adygea / drinking water supply		micro-hydroelectric power station-10
Adygea / drinking water supply
Kabardino-Balkaria / Akbash
Krasnodar region / Krasnodar CHP
Republic of Tuva / Ush Beldyr		micro-hydroelectric power station-10
Republic of Tuva / settlement Kyzyl Khaya, r. Mochen-Buren		micro-HPP-50PR
Republic of Altai / Kairu
Karelia / Kiwi-Koivu		micro-HPP-50D
Karelia / Landenpohskiy district		micro-hydroelectric power station-10
Leningrad Region / Luga		micro-HPP-50PR micro-hydroelectric power station-10
Bashkiria / Tanalyk reservoir		micro-HPP-50PR
Bashkiria, pos. Tabuldy		micro-hydroelectric power station-10
Bashkiria / Uzyan reservoir		micro-HPP-50PR
Bashkiria / Sokolki		micro-HPP-50PR
Moscow region, lake. Senezh		Vetro-MHES		2 hydraulic units 2 wind turbines
Yaroslavl region R. Nerl-Volzhskaya		Recovery SHPP
When compiling the table, the following sources were used: 1) YI Blyashko, Experience of MNTO INSET on the creation and operation of equipment for micro and small hydroelectric power plants, periodical scientific and technical journal "Malaya energetics" No. 1, 2004; 2) Malik L.K. Problems and prospects of creating small hydroelectric power plants on small rivers, periodical scientific and technical journal "Malaya energetics" No. 1, 2004; 3) Historian B.L., Usachev I.N., Shpolyansky Yu.B., Small non-traditional marine, river and geothermal energy, periodical scientific and technical journal "Malaya energetics" No. 1, 2004.

In terms of their potential, Russia's hydro resources are comparable to the existing volumes of electricity generation by all power plants in the country, but this potential is used by only 15%. Due to the growing costs of fossil fuel extraction and the corresponding increase in its cost, it seems necessary to ensure the maximum possible development of hydropower, which is an environmentally friendly renewable source of electricity.

With optimistic and favorable development scenarios, electricity generation at hydroelectric power plants may increase to 180 billion kWh in 2010 and up to 215 billion kWh in 2020, with a further increase to 350 billion kWh due to the construction of new hydroelectric power plants. It is assumed that hydropower will mainly develop in Siberia and the Far East. In European regions, the construction of SHPPs will be developed in the North Caucasus.

Historical excursion

At present, the hydropower potential is almost fully realized at the expense of large and giant hydroelectric power plants. At the same time, according to the available data, in 1913 the number of hydroelectric power plants operating in Russia was 78 units, with a total capacity of 8.4 MW. The largest of them was the hydroelectric power station on the river. Murghab, with a capacity of 1.35 MW. Thus, according to the modern classification, all hydroelectric power plants operating at that time were small.

Less than 30 years later, in 1941, 660 small rural hydroelectric power plants operated in Russia with a total capacity of 330 MW. The 40s and 50s of the XX century saw the peak of the construction of small hydroelectric power plants, when up to 1000 objects were put into operation every year. According to various estimates, by 1955 there were from 4,000 to 5,000 SHPPs in the European part of Russia. And the total number of SHPPs in the USSR after the end of World War II was 6,500 units.

True, already in the early 50s, due to the transition to the construction of gigantic energy facilities and the connection of rural consumers to centralized power supply, this direction of energy lost state support, which led to almost complete destruction and decline of the previously created infrastructure. The design, construction, manufacture of equipment and spare parts for small hydropower has ceased.

In 1962, there were 2,665 small and micro HPPs in the USSR. In 1980 there were about 100 of them with a total capacity of 25 MW. And by the time of the collapse of the USSR in 1990, there were only 55 operating SHPPs. According to various sources, at present there are from several dozen (60-70) to several hundred (200-300) units operating throughout Russia.

The program for the development of hydropower in the USSR until 2000 provided for an increase in the capacity of existing hydroelectric power plants almost twofold. It was planned to build 93 new hydroelectric power plants, flood 2 million hectares of fertile land and relocate more than 200 thousand people from the flooded territories. (Small hydroelectric power stations did not find a place in these plans.) The collapse of the USSR and the economic crisis did not allow the implementation of these grandiose plans.

Over the past 10 years, the share of electricity generated at hydropower plants in the total energy balance of Russia has been declining. In 1995 it was 21%, in 1996 - 18%, in 1997 - 16%. This is due both to the obsolescence and wear and tear of equipment at the hydropower giants of the past, and to the increase in the country's energy balance of the share of a more convenient energy resource - natural gas.

According to experts, in the near future, power generation at hydroelectric power plants will increase. This will take place mainly in regions with decentralized power supply due to the commissioning of new small hydroelectric power plants, which will replace obsolete and uneconomical diesel power plants.

Place of small hydropower among other VIZ

In the production of electricity, small hydropower in Russia shares the lead with thermal power plants using biofuel. According to available data for 2002 and 2003, SHPPs and bio-TPPs produced approximately equal amounts of electricity - 2.4 billion kWh each (2002) and 2.5-2.6 billion kWh each (2003). That is, the contribution of each of these resources to electricity generation in Russia was less than 0.3%.

The total installed capacity of 59 SHPPs, information about which we have, was 610 MW in 2001. According to expert estimates, this figure is currently higher. At the same time, the average ICUF values \u200b\u200bfor operating small HPPs were 38-53%, and such an important indicator for calculating the efficiency of a power plant, such as electricity consumption for auxiliary needs, did not exceed 1.5%.

The Federal Target Program “Fuel and Energy”, adopted in 1997, provided for the acceleration of the creation of small hydroelectric power plants, but weak budgetary funding did not allow its full implementation.

Despite the financial problems, the construction of new and restoration of the previously operating, but stopped and partially destroyed small hydroelectric power plants is underway. In most cases, their construction and commissioning is carried out without the participation of federal budget funds. For this, funds are attracted from local budgets, funds from sponsors and investors.

New construction is dominated by micro-hydroelectric power plants with a unit capacity of units from 10 to 50 kW, combined into systems of 2-5 units. Small hydroelectric power plants with a unit capacity of units from 200 to 550 kW, combined into systems of 2-7 units, are being built.

As a rule, SHPPs are created in remote areas where there is a problem with the delivery of fossil fuel (in most cases - diesel fuel, less often - coal). In Adygea, 2 small HPPs with a capacity of 50 and 200 kW were built, used for supplying drinking water. A small hydroelectric power station with a capacity of 1100 kW was built in Kabardino-Balkaria. In 2003, 7 hydraulic units of 350 kW each were installed in the Krasnodar Territory. In the Republic of Tyva and Altai, 3 small hydroelectric power plants with units of 10, 50 and 200 kW, combined by 2-3 units, have been built. In Karelia and the Leningrad region. - 4 mini-hydroelectric power plants with units from 10 to 50 kW. There are also 4 mini-hydroelectric power plants in Bashkiria with units from 10 to 50 kW. In addition, other small HPPs were built or rebuilt.

Expected shifts in the energy balance

According to experts, the main purpose of the SHPP in the coming years will be to replace organic fuel (primarily diesel) imported to remote regions of Russia in order to reduce federal budget expenditures and increase the efficiency and energy security of energy-deficient regions. The construction of SHPPs is carried out in protected natural areas and in places with a fairly stable water regime in small streams.

It is planned to create 5 small HPPs on the rivers of the Koryak Autonomous Okrug. This will make it possible to replace up to 18 thousand tons of diesel fuel in the energy balance, which is 30% of the total volume imported to the region annually.

More than 3000 diesel power plants (DPP) with a capacity of up to 500 kW are currently operating in the Far East region. The power supply of the region depends entirely on the stability of the supply of diesel fuel and the quality of equipment for its combustion. The cost of both diesel fuel itself and its delivery is currently so high that there is an urgent need to replace it with other energy resources. In addition, the wear and tear of the equipment of most diesel power plants is so great that it is necessary to urgently address the issue of stability of the region's power supply.

Under these conditions, organizations that design SHPPs and carry out relevant surveys of small watercourses have identified more than 200 sites for the construction of SHPPs, which, according to rough estimates, will produce up to 1.5 billion kWh of electricity per year. According to later studies, the power supply of a number of settlements in the Far East and Primorye can be optimized through the construction of 7-8 SHPPs located near consumers and integrated into the local power system.

The implementation of these projects will help to reduce the volume of diesel fuel imported to the region by 28 thousand tons per year, which will free up vehicles and reduce the load on local ports. All this will significantly increase the energy independence of the Far East and Primorye.

Possibilities for the restoration of destroyed SHPPs

In different regions of Russia, to this day, there are ruins of small hydroelectric power stations, which in the middle of the 20th century supplied settlements and agricultural enterprises with electricity. The engineering surveys of the destroyed SHPPs carried out in recent years have shown that concrete structures have survived at many facilities, the restoration of which can be economically justified.

Among the advantages of reconstruction and restoration of destroyed SHPPs, experts name the following: autonomous supply of local consumers with electricity, independence from the networks of RAO UES of Russia; reducing the cost of creating local power lines; reducing the load on the local electric networks of RAO UES of Russia; reducing the cost of expensive fossil fuels; ecological cleanliness of hydropower.

Since 1995, the Research Institute for Power Engineering has been working on creating a database of hydraulic structures and small hydroelectric power plants on small rivers of the European part of Russia. At present, the database contains information about 200 similar objects on the rivers of the upper and middle Volga basin, as well as in the northwest of Russia. Engineering survey of structures was carried out for 100 objects. A number of objects have design documentation. Almost all hydraulic engineering facilities included in the database included hydroelectric installations. Cascades of 2-6 small hydroelectric power stations were built on the rivers, which formed the economic coastal infrastructure. In addition, the cascades provided flood protection.

NIIES specialists have examined some partially destroyed SHPPs and carried out feasibility studies for their restoration. Among the surveyed objects are Veselovskaya SHPP (Rostov region), Kopylkovskaya SHPP (river Velikaya, Pskov region), Petrovskaya and Mirslavlskaya SHPP (river Nerl, Ivanovskaya region).

To search for optimal engineering and technical solutions for the restoration of small hydroelectric power plants, the Khorobrovskaya small hydroelectric power station was built in 2003 (the Nerl-Volzhskaya river, Yaroslavl region) with a capacity of 160 kW, generating 840 thousand kWh of electricity. It was restored as a permanent experimental base of JSC NIIES RAO "UES of Russia" for field testing of new technologies and equipment for the technical re-equipment of hydropower - incl. small. This SHPP operates in a fully automatic mode both in terms of power generation and flood control. Experimental automatic gates and Hydroplus were installed at the spillway dam of the MHPP, made with the participation of French specialists.

In 2004, on the lake. The restored small hydropower plant of the 19th century by Baron Knopp, built on the basis of hydropower facilities of the mid-18th century, was commissioned in Senezh (Moscow Region). The hydroelectric equipment of the restored SHPP is an orthogonal hydroturbine that makes it possible to effectively use low-pressure dams manufactured at the Prometey enterprise in Chekhov near Moscow. In addition to the SHPP, orthogonal power wind turbines with a new design of aerodynamic braking have been installed on its dam. The combination of SHPP and wind turbine operation will optimize the production of electrical power supplied to the local grid.

The total capacity of the hydro-wind farm is 70 kW. It consists of two 10 kW wind turbines and two 45 and 5 kW hydroelectric units. During the tests, it is planned to test the ability of the integrated system to operate on the network and on the local load, which will allow the use of such power complexes for power supply to consumers in remote regions.

In general, we can say that small hydropower in its development is experiencing the same problems as energy technologies for other renewable energy sources. If only a few percent of the subsidies allocated from the federal budget to support thermal or nuclear energy, or the so-called "northern fuel delivery", were directed by state structures to the development of renewable energy, our country could look into the future with much greater optimism ...

Small hydropower is understood as the production of electricity using hydro turbines of various capacities installed on permanent watercourses. As a rule, the creation of a hydroelectric power station (HPP) requires the construction of a dam in which hydro turbines are installed, but it is also possible to create a damless hydroelectric power station.

Micro-hydroelectric power stations mean stations with a capacity of up to 100 kW, and under small ones (SHPPs) - with a total installed capacity of up to 30 MW with a single hydroelectric unit capacity of up to 10 MW and a turbine runner diameter of up to 3 m. In most cases, it is assumed that small hydroelectric power plants are installed on small rivers and streams. SHPPs can operate on a regulated runoff or without backwater on a natural runoff. For small hydroelectric power plants, idle discharges through the dams of large hydroelectric complexes and sluices, level drops of large masses of water at industrial enterprises, water discharges from mining and processing plants, thermal power plants, state district power plants, nuclear power plants, etc. are also used. Small hydroelectric power plants are also built on irrigation canals.

Like any other method of energy production, the use of small and micro-hydroelectric power plants has both advantages and disadvantages.

The problem of small hydropower plants is their vulnerability in terms of failure, as a result of which consumers are left without energy supply. The solution to the problem is the creation of reserve generating capacities - a wind turbine, a cogeneration mini-boiler house, a photovoltaic installation, etc.

There is a certain seasonality in electricity generation, when in winter and summer periods, due to a decrease in consumption on the watercourse, the capacity of the SHPP significantly decreases.

The factors that hinder the development of small hydropower in Russia are:

lack of information from potential users about the benefits of using SHPP;
poor knowledge of the hydrological regime of small streams;
lack of scientifically based methods for assessing and predicting possible impact on the environment and economic activity;
low production and repair base of enterprises producing equipment for SHPPs;
lack of serial equipment for the mass construction of SHPPs.

Even in ancient times, man drew attention to rivers as an accessible source of energy. To harness this energy, people learned to build water wheels that were turned by water. These wheels set in motion millstones and other installations. The water mill is a striking example of the oldest hydropower plant, which has survived in many countries to this day almost in its original form. Before the invention of the steam engine, water energy was the main driving force in production. As the water wheels improved, the power of the hydraulic units that set the machine tools in motion increased. In the first half of the 19th century, the water turbine was invented, which opened up new possibilities for the use of hydropower resources. With the invention of the electric machine and the method of transmitting electricity over long distances, the development of water energy began by converting it into electrical energy at hydroelectric power plants (HPPs).

Small and micro hydroelectric power plants are small hydropower facilities. This part of the energy production deals with the use of energy from water resources and hydraulic systems with the help of hydropower plants of low power (from 1 to 3000 kW). Small-scale energy has developed in the world in recent decades, mainly due to the desire to avoid environmental damage caused by the reservoirs of large hydroelectric power plants, due to the ability to provide energy supply in remote and isolated areas, as well as due to low capital costs during the construction of power plants and fast return on investment. The construction of SHPPs also has broad development prospects in various regions of the world with transboundary river basins.

At present, there is no concept of a small hydroelectric power station generally accepted for all countries. However, in many countries, its installed capacity is taken as the main characteristic of such a hydroelectric power plant. Small, as a rule, include hydroelectric power plants with a capacity of up to 30 MW. Small hydropower is free from many of the disadvantages of large hydroelectric power plants and is recognized as one of the most economical and environmentally friendly methods of generating electricity, especially when using small watercourses. Small, micro or nano HPPs combine the advantages of a large HPP on the one hand and the possibility of a decentralized power supply on the other.

In recent years, the practice of installing small hydroelectric power plants has become widespread. A power plant of this type is an installation, all types of equipment of which are hydroelectric devices. Depending on the capacity of the installations, they are calibrated at mini-hydroelectric power plants with a capacity not exceeding 10 MW, micro-hydroelectric power plants with a capacity not exceeding 0.1 MW, and small hydroelectric power plants with a capacity of 10 to 30 MW. The diagram of the hydroelectric power plant is shown in Fig. 2.1.

Figure: 2.1. Diagram of the hydroelectric power plant: 1 - reservoir; 2 - shutter; 3 - transformer substation with switchgear; 4 - hydrogenerator; 5 - hydraulic turbine

The hydroelectric unit of a small hydroelectric power plant consists of a power unit, a water intake unit and control elements. By the type of hydro resources that are used in the operation of small hydroelectric power plants, they can be divided into:

river-bed or dam-type stations with small reservoirs;
stationary mini-stations, which use the energy of the free flow of rivers;
hydroelectric power plants that use energy from existing water level differences.

Turbines for small hydroelectric power plants exist:

axial type;
radial-axial execution;
bucket construction;
with rotary vane devices.

Turbines are used depending on the water pressure used by the hydroelectric power plant. So, bucket and radial-axial turbines are designed and used for high-pressure mini-stations. Turbines with rotary vane and radial-axial devices are used at medium-pressure hydroelectric power plants. At low-pressure, low-power plants, rotary-blade turbines are installed.

The principle of operation of all types of turbines is the same, under the pressure of the water entering the blades, they carry out rotational movements. The power of all hydroelectric mini-stations depends on the water pressure and its consumption, on the efficiency of the installed generators and turbines.

When choosing a low-power HPP, it is necessary to take into account that all equipment must be adapted for specific conditions, meet the needs and purpose of the facility and meet certain aspects. All equipment should be equipped with automatic control and monitoring systems with the ability to switch to manual control in cases of emergency and sudden power outages. Small hydropower plants must be equipped with reliable protection and safety systems.

One of the main advantages of small hydropower facilities is environmental safety. In the process of their construction and subsequent operation, there are no harmful effects on the properties and quality of water. The reservoirs can be used both for fishery activities and as sources of water supply for the population. However, besides this, micro and small hydroelectric power plants have many advantages. Modern stations are simple in design and fully automated. The electric current generated by them meets the requirements of GOST in terms of frequency and voltage, and the stations can operate both autonomously and as part of the power grid. Small-scale energy facilities do not require the organization of large reservoirs with corresponding flooding of the territory and colossal material damage.

During the construction and operation of the SHPP, the natural landscape is preserved, there is practically no load on the ecosystem. The advantages of small hydropower, compared to power plants using fossil fuels, can also include: low cost of electricity and operating costs, relatively inexpensive replacement of equipment, a longer service life of hydroelectric power plants (40-50 years), complex use of water resources (electricity, water supply, melioration, water protection, fisheries).

Many of the small hydropower plants do not always provide guaranteed energy production, being seasonal power plants. In winter, their energy output drops sharply, snow cover and ice phenomena (ice and sludge), as well as summer low water and drying up of rivers, can stop their work altogether. The seasonality of small hydroelectric power plants requires duplicate energy sources; a large number of them can lead to a loss of reliability of power supply. Therefore, in many regions, the capacity of small hydropower plants is considered not as the main one, but as a redundant one.

In the reservoirs of small hydroelectric power plants, especially in mountainous and foothill regions, there is a very acute problem of their siltation and the related problem of rising water levels, flooding and flooding, reducing the hydropower potential of rivers and generating electricity.

The construction and reconstruction of small hydroelectric power plants will allow not only to receive environmentally friendly electricity, but also to provide electricity to energy-deficient areas where there is no centralized power supply. The development of small hydropower contributes to the decentralization of the overall energy system, which makes it possible to consistently provide hard-to-reach regions with electricity. The energy generated by small hydroelectric power plants is used by nearby consumers. At the same time, expenses for its transportation are reduced, and the reliability of power supply increases.

Small hydropower is one of the most understandable directions for the development of renewable energy sources for investors. The development of small hydropower is now promising in areas with a high density of hydropower resources, especially in regions where there is no centralized power supply and capacity shortages (Fig. 2.2).

Figure: 2.2. Hydropower resources of the regions of the Russian Federation

The most promising regions of the Russian Federation for the development of small hydropower are the Republics of the North Caucasus: Dagestan, Chechnya, Ingushetia, Karachay-Cherkessia, Kabardino-Balkaria, North Ossetia, Adygea, as well as Stavropol and Krasnodar Territories, Karelia, Murmansk Region, South Siberia and the Baikal region regions of the Far East.

Hydropower potential, like other natural resources, is assessed in several categories to reflect natural-physical, technical and socio-economic aspects. Three categories of assessment are defined:

gross hydropower potential, i.e. full supply of energy carried by rivers;
technical hydropower potential - a part of the gross, the development of which is, in principle, feasible with the help of known technical means;
economic hydropower potential is a technical part, the development of which seems to be economically efficient and expedient.

Gross potential (theoretical or potential hydropower resources) is determined by the formula

where E - energy, kWh; Q i - the average annual discharge of the river for i-m considered area, m 3 / s; H i - drop in the river level in this section, m; n is the number of sites; 8760 is the number of hours in a year.

They are calculated on the assumption that the entire effluent will be used to generate electricity without losses by converting hydraulic energy into electrical energy.

The world's potential hydropower resources are estimated at 35,000 billion kWh per year, Russia's potential resources amount to 2,896 billion kWh.

Technical hydropower resources are always less than theoretical, since they take into account losses:

hydraulic heads in water conduits, ponds, on unused sections of watercourses;
water consumption for evaporation from reservoirs, filtration, idle discharges, etc .;
energy in various hydropower equipment.

Technical resources characterize the possibility of obtaining energy at the present stage.

Technical hydropower resources in Russia amount to 1,670 billion kWh per year, including 382 billion kWh per year for small hydro power plants.

Electricity generation at the existing hydroelectric power plants in Russia in 2002 amounted to 170.4 billion kWh, including 2.2 billion kWh at small HPPs.

Economic hydropower resources significantly depend on progress in the energy sector, the remoteness of the hydroelectric power station from the place of connection to the power system, the provision of the region under consideration with other energy resources, their cost, quality, etc.

Table 4.1 shows the values \u200b\u200bof the economically efficient hydropower potential of Russia.

Table 4.1 Economically effective hydropower potential of Russia, TWh s / year

In 2003, Russia’s SHPPs generated about 2.5 billion kWh of electricity, which was less than 0.3% of the total electricity generation in Russia. For comparison, at the end of the 1980s, small hydroelectric power plants in the United States and China, respectively, generated 28 and 11 billion kWh of electricity.

In terms of their potential, Russia's hydro resources are comparable to the existing volumes of electricity generation by all power plants in the country, but this potential is used by only 15%. In connection with the growing costs of fossil fuel extraction and the corresponding increase in its cost, it seems necessary to ensure the maximum possible development of hydropower. It is assumed that hydropower will mainly develop in Siberia and the Far East. In European regions, the construction of SHPPs will be developed in the North Caucasus.

Small rivers account for about 17% of the country's total hydropower potential. The full energy potential of these rivers is estimated at 360 million tons of fuel equivalent. per year, of which technical - 125 million tons of fuel equivalent. (35%), economic - 65 million tons of fuel equivalent. (18%). It can be realized through the construction of small hydropower plants.

About 40% of the hydroelectric potential of the rivers of the North Caucasus falls on Dagestan, which in the total energy potential is 50.8 billion kWh per year. Until the 1990s. the economically feasible potential of the rivers of Dagestan was estimated at 16 billion kWh. Of these, 12 billion kWh was supposed to be developed by large and medium-sized hydroelectric power plants, and 4 billion kWh - by small hydroelectric power plants. Currently, there is a reassessment of the economically feasible potential of the rivers of Dagestan, towards its increase, including the share of small hydroelectric power plants.

For the 1940-1950s. the peak of the construction of small hydroelectric power plants occurred, when up to 1000 objects were commissioned annually. According to various estimates, by 1955, there were from 4,000 to 5,000 SHPPs in the European part of Russia. And the total number of SHPPs in the USSR after the end of World War II was 6,500 units.

In the early 1950s, in connection with the transition to the construction of large energy facilities and the connection of rural consumers to the centralized power supply, this direction of the energy sector lost state support, which led to almost complete destruction and decline of the previously created infrastructure. The design, construction, manufacture of equipment and spare parts for small hydropower has ceased.

By the time of the collapse of the USSR in 1990, only 55 SHPPs remained in operation. According to various sources, there are currently from 70 to 350 SHPPs operating throughout Russia.

In recent years, the share of electricity generated at hydropower plants in the total energy balance of Russia has been declining. In 1995, it was 21%, in 1996 - 18%, 1997 - 16%. This is due both to the obsolescence and wear and tear of equipment at the hydropower giants of the past, and to the increase in the country's energy balance of the share of a more convenient energy resource - natural gas.

According to experts, in the near future, power generation at hydroelectric power plants will increase. This will happen mainly in regions with decentralized power supply due to the commissioning of new SHPPs, which will replace obsolete and uneconomical diesel power plants.

The main purpose of the SHPP in the coming years will be to replace organic fuel imported to remote regions of Russia in order to reduce federal budget expenditures and increase the efficiency and energy security of energy-deficient regions.

More than 3000 diesel power plants operate in the Far East region. The power supply of the region is completely dependent on the stability of diesel fuel supplies. Due to the high cost of diesel fuel and its delivery, it became necessary to replace it with other energy resources. The power supply of the region can be optimized through the construction of a small hydroelectric power station.

In recent years, schemes for the use of hydro resources have been developed and priority projects for possible construction have been identified, taking into account the needs of consumers. On the Kamchatka Peninsula, it is planned to build 20 SHPPs. First of all, it is planned to commission six HPPs with a total installed capacity of 50.2 MW. These power plants will be built on rivers where commercial fish farming is not developed, or they will be built without dams. In the second phase, another 11 HPPs with a total capacity of 132.8 MW will be commissioned. By 2015, the construction of three more HPPs will be completed, with a total capacity of 300 MW.

The North Caucasus also belongs to the energy-deficient regions. In recent years, small HPPs have been built in Adygea (250 kW), Kabardino-Balkaria (1100 kW), Krasnodar Territory (2450 kW).

Under the program for the construction of small hydropower plants in Dagestan, 20 most promising projects in the basin of the river were selected. Sulak with a total capacity of 46,200 kW, electricity generation of 274.4 million kWh and 12 most promising small HPPs in Southern Dagestan with a total capacity of 11,700 kW, with a total average annual electricity generation of 68 million kWh. Akhtinskaya SHPP (1800 kW), Agulskaya SHPP (600 kW), Arakulskaya SHPP (1200 kW), Amsar SHPP (1000 kW), Kurushskaya SHPP (480 kW), Bavtugayskaya SHPP (600 kW), Gunibskaya SHPP (15,000 kW) ), Maginskaya SHPP (1200 kW), Shinazskaya SHPP (1400 kW).

The program of JSC HydroOGK for the construction and rehabilitation of small hydroelectric power plants provides for the commissioning of 300 MW capacities at small hydropower plants by 2010 and 3000 MW capacities by 2020 (mainly in the North Caucasus).

The expansion of the SHPP network will allow supplying mountainous areas with electricity in full, which will lead to a sharp improvement in the social conditions of highlanders, the expansion of existing and creation of new industries (irrigation systems, workshops for the production of building materials, water supply and sanitation systems, agro-industrial complexes, etc. ) and, accordingly, to the creation of additional jobs. Ultimately, the supply of electricity to mountain areas based on the use of renewable and environmentally friendly hydraulic energy will contribute to the revival and development of remote mountain villages and the consolidation of the indigenous population.

The following schemes can be used to create a pressure at a hydroelectric power station:

dam, in which the head is created by the dam;
derivational, when the pressure is created by means of derivation (diversion, deviation), performed in the form of a channel, tunnel or pipeline;
combined, in which the head is created by a dam and a derivation.

The dam scheme provides for the creation of a backwater of the watercourse level by constructing a dam. The resulting reservoir can be used as a regulating tank, which allows periodically accumulating water reserves and more fully using the energy of the watercourse.

In the diversion scheme, water is withdrawn from the natural bed through an artificial water conduit with a smaller longitudinal slope. The water level at the end of such a conduit turns out to be higher than the water level in the river, and this level difference is the head of the hydroelectric power station. The greater the slope of the river and the longer the derivation, the greater the head can be obtained. The derivation can be free-flow - channel, chute, free-flow tunnel or pressure - pressure tunnel, pipeline. In practice, there are mixed hydroelectric power plants: dam-diversion, in which the pressure is created both by the dam and by the derivation, and mixed diversion, in which there are both pressure and non-pressure water conduits.

Derivation hydroelectric power plants are built on mountain rivers and foothill areas where there are significant slopes. With the help of derivation, heads of 1000 m and more can be obtained.

Hydro-turbines and generators are the main power equipment of HPPs.

A hydraulic turbine converts the energy of water movement into mechanical energy of rotation of its impeller. Depending on the principle of energy conversion, hydro turbines are divided into active and reactive.

Active turbines use the kinetic part of the flow energy (velocity head).

Jet turbines (Figure 4.1) use mainly the potential energy of the flow (pressure energy).

Figure: 4.1. Reactive axial turbine

At a hydroelectric power station, the turbine and generator are connected by a common shaft. The frequencies of their rotation depend on the number of pairs of poles of the generator rotor and the frequency of the alternating current, which must correspond to the standard. To obtain the speeds of the units close to the optimal ones, at high heads, turbines with low values \u200b\u200bof the speed coefficient are used, and at high heads, with large values \u200b\u200bof this coefficient.

The INSET Association (St. Petersburg) produces hydroelectric units for small HPPs with a unit capacity of up to 5000 kW and for micro-HPPs with a capacity of 3 to 100 kW. The hydraulic units are designed for operation in a wide range of heads and flow rates with high energy characteristics and are produced with propeller, radial-axial and bucket turbines. The delivery set includes, as a rule, a turbine, a generator and an automatic control system for the hydraulic unit.

JSC "Tyazhmash" (Syzran) supplies hydraulic turbines with a capacity of 15,000 for small hydroelectric power plants, and also carries out repair and restoration of individual units, installation and adjustment of equipment.

Hydropower equipment for small hydroelectric power plants is being developed by NPO RAND (St. Petersburg). Hydraulic turbines have been designed that make it possible to effectively use low heads. The capacity of such installations ranges from 6–20 to 2500 kW.

In recent years, free-flow submersible hydro turbines have been developed that use the speed of water flow in watercourses to obtain power and do not require the construction of dams. For the placement of submersible hydro turbines, watercourses can be used that have a sufficient width and depth, as well as a water flow velocity of the order of 3 m / s.

Portable submersible water turbines can be widely used when you need to quickly generate electricity with minimal time and financial costs.

Micro-hydroelectric power plants (up to 100 kW) can be installed almost anywhere. The hydraulic unit consists of a power unit, a water intake device and an automatic control device (Figure 4.2).

Figure: 4.2. Micro-hydroelectric power station

Micro-hydroelectric power plants are simple. They are reliable, environmentally friendly, compact, and quickly pay off. First of all, micro-hydroelectric power plants are in demand as sources of electricity for villages, farms, summer cottages, farms; mills, small industries in remote, mountainous and hard-to-reach areas where there are no power lines nearby (and building such lines now takes longer and more expensive than purchasing and installing micro-hydroelectric power plants).

A large number of micro-hydroelectric power plants can be built on water supply and irrigation hydropower facilities. In water supply systems on sections of the route with a large difference in surface marks, instead of various types of energy absorbers (pressure), micro-hydroelectric power plants can be built. With water flow rates ranging from 5 to 100 l / s, their power can reach from 20 to 200 kW.

Some foreign firms are implementing interesting design solutions. Figure 4.3 shows the design of an inflatable spillway dam offered by Dyrhoff. Instead of materials traditional for dams: concrete, steel and wood, the company uses a "bubble" made of reinforced rubber. To create pressure, the dam is inflated with air or filled with water at a pressure of 20–30% greater pressure (h).

Figure: 4.3. Inflatable spillway dam

On the concrete base, the bubble is held in place with anchors. The compressor or pump is connected to the inner cavity of the dam through a pipeline located in the concrete base. The convenience of this design lies in the fact that, if necessary, you can quickly and easily release air from the cavity and the "bubble" will sink to the bottom, allowing the water to pass unhindered downstream. This property of the dam can be used in the best way on rivers with rapidly increasing high-water floods for transit water passage. It is possible to use these dams for seasonal passage of fish and ice. The advantages of this dam, according to the manufacturer, are low cost, ease of operation and minimal operating costs.

Figure: 4.4. Coanda Screen Dam

Another, no less interesting project is the Coanda screen water intake dam (Figure 4.4). Today, more than 40 water intakes of small hydroelectric power plants in Europe are equipped with such screens. These screens are self-cleaning and therefore require little maintenance. Essentially, the water intake consists of a weir, through the crest of which water overflows and on the lower side of which there is an inclined profiled surface of a screen made of corrosion-resistant material. Through the lattice structure of the screen, water falls down and enters a pipeline or channel that supplies water to the hydroelectric power station. Due to the special configuration of the lattice rods, floating debris, sediments and fish slide down the screen with some part of the water. The Coanda screen is capable of eliminating 90% of particles as small as 0.5 mm.

The accelerated development of small hydropower can be prompted by accidents that have become more frequent in the country's energy system, since hydroelectric units can be sources of autonomous power supply. Another acceleration factor is the environmental requirements for the generated energy, which has become even more urgent in connection with the introduction of the Kyoto Protocol.

Today, small hydroelectric power plants (micro-hydroelectric power plants) have already become widespread in many countries of the world. They are characterized by large hours of operation, significant design reserves and high reliability, do not require the constant presence of service personnel. The environmental impacts from the construction and operation of SHPPs are minimal. Small hydropower is practically independent of weather conditions and is able to provide a stable supply of electricity to the consumer. SHPPs generate cheap electricity, and their payback period does not exceed 3-5 years.

Power (kW) at the turbine shaft is defined as

where Q t - water flow rate through the turbine m 3 / s; H - turbine head, taking into account losses, m; η t is the coefficient of efficiency (efficiency) of the turbine (η t \u003d 0.93–0.96).

Electric power of the generator

where η gene is the efficiency of the hydrogenerator, usually equal to 0.97.

The power of the unit is controlled by changing the flow rate of water passing through the hydraulic turbine. HPP capacity in i-th moment of time is

where Q g i, H g i, η g i - flow rate, head and efficiency of the HPP in ith moment in time.

Electricity generation by HPPs (kWh) for a period of time T (h) is determined by the formula

The annual electricity generation by a hydroelectric power station is not a constant value, but varies depending on the volume of runoff entering the reservoir, the degree of its regulation and the operating conditions of the hydroelectric power station.

The electrical power supplied to the consumer is less than the power produced by the HPP. The sum of all losses during the transmission of electricity from the hydroelectric power station to the consumer is estimated using the efficiency of the transmission and conversion system η trans \u003d 0.92–0.93.

The installed capacity of the HPP N mouth is determined as the sum of the nominal (passport) capacities of the generators installed on it. It corresponds to the maximum capacity that a hydroelectric power plant can develop.

table 2

Some characteristics of SHPPs operating in Russia

Installations (by years)

Total installed capacity (by years) (MW)

Total available capacity (by years) (MW)

KIUM * (by years) (%)

KIRM ** (by years) (%)

Electricity consumption for own needs (% of generation)

Small HPPs owned by JSC Energo

Small HPPs not included in JSC Energo

* KIUM - coefficient of installed capacity utilization.

** KIRM - utilization factor of available power.

When compiling the table, sources of information were used:

1) Problems and prospects for the development of renewable energy sources in Russia (materials of the round table), the Russian Union of Scientific and Engineering Societies, the Committee of the Russian Scientific Research Institute on the Problems of the Use of Renewable Energy Sources. Moscow, 2003.

2) Vashkevich K.P., Maslov L.A., Nikolaev V.G. Experience and prospects for the development of wind energy in Russia, periodical scientific and technical journal "Small Energy", No. 1-2, 2005.

A pumped storage power plant (PSPP) is designed for the time redistribution of energy and power in the power system. During hours of reduced loads, the PSP works as a pumping station. Due to the consumed energy, it pumps water from the downstream to the upstream and creates reserves of hydropower (Fig. 4.5).

Figure: 4.5. Schematic diagram of pumped storage power plant

During the hours of maximum load, the PSP works as a hydroelectric power station. Water from the headwater is passed through turbines to the downstream, and the pumped storage plant generates and delivers electricity to the power system. In the course of operation, the PSPP, due to the difference in tariffs, consumes cheap electricity, and produces more expensive electricity during the peak load period (at night the cost of electricity is lower due to low demand, and during the day there is not enough electricity). Filling the load gaps in the power system, the PSPP allows operating thermal and nuclear power plants in the most economical and safe mode, while sharply reducing the specific fuel consumption for the production of 1 kWh of electricity in the power system.

Thus, the PSP does not generate energy, but only redistributes it in time by pumping water from the lower basin to the upper one at night and using the stored energy during periods of maximum load by passing water from the upper basin to the lower one through the PSPP turbines.

The advantage of the PSPP is the small volume of required specific capital investments and the number of maintenance personnel. They do not require the presence of large rivers, have a lower impact on the environment compared to other energy sources, work well and are widely used in the synchronous compensator mode, generating reactive power.

At pumped storage power plants, mainly reversible hydraulic machines are used, operating in both pumping and turbine modes, and reversible electric machines operating as a generator or an electric motor. Reversible hydraulic machines are designed for heads up to 1000 m.

The efficiency of a PSPP largely depends on the amount of head used: the higher it is, the more efficient the PSPP, which is primarily associated with a decrease in the capacity of the pools. Thus, specific capital investments in pumped storage power plants with an increase in head from 100 to 500 m decrease by 20-25%.

In industrialized countries, the intensive commissioning of new hydropower facilities is provided, as a rule, by the construction of pumped storage power plants.

Zagorskaya PSPP-1 is the first and so far the only PSPP in Russia. The PSPP-1 is located 100 km north of Moscow on the Kunya River, which feeds the lower reservoir of the PSPP. During its construction, the natural height difference between the upper and lower basins, reaching 100 m, was used. With the commissioning of the last unit in 2000, PSHPP-1 reached its design capacity of 1200 MW. To solve the power supply of the Central region of Russia, it is necessary to build four more similar stations.

Unlike hydroelectric power plants, pumped storage power plants use water in a closed cycle to generate electricity and cause minimal damage to the environment. To replenish water losses due to evaporation and seepage into the ground, the water circulating between both basins is replenished. Make-up is carried out from an open source and its flow rate is much lower than the circulation flow rate.

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