Like any other method of energy production, the use of small and mini hydroelectric power plants has both advantages and disadvantages.
Among the economic, environmental and social advantages of small hydropower facilities are the following. Their creation increases the energy security of the region, ensures independence from fuel suppliers located in other regions, and saves scarce organic 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 pays off relatively quickly. It should be noted that the reconstruction of a previously decommissioned small hydroelectric power station will cost 1.5-2 times less. Small-scale energy facilities do not require the organization of large reservoirs with corresponding flooding of the territory and colossal material damage.
In addition, there are opportunities to reduce construction costs through unification and certification of equipment. Modern stations are simple in design and fully automated, i.e. do not require human presence during operation. The electric current they generate meets GOST requirements for frequency and voltage, and the stations can operate in autonomous mode, i.e. outside the power grid of the region's energy system, and as part of this power grid. And the full service life of the station is at least 40 years (at least 5 years before major repairs).
One of the main advantages of small hydropower facilities is environmental safety. During their construction and subsequent operation there are no harmful effects on the properties and quality of water. Reservoirs can be used for fishing activities and as sources of water supply for the population. In the process of generating electricity, the hydroelectric power station 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 do not cause induced seismicity and are relatively safe during the natural occurrence of earthquakes. They do not have a negative impact on the lifestyle of the population, on the animal world and local microclimatic conditions.
A significant advantage is also the absence of disturbance to the natural landscape and environment during the construction process and during the operation stage, as well as almost complete independence from weather conditions. The supply of cheap electricity to the consumer is ensured at any time of the year. ??????????????? ????????????? ???????
In addition, mini-hydroelectric turbines can also be used as energy absorbers at differences in heights of drinking and other pipelines intended for pumping various types of liquid products.
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 isolated use, a small hydropower facility is vulnerable to 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 using biofuel, photovoltaic installation, etc.).
The most common type of accident at small hydropower facilities is the destruction of the dam and hydraulic units as a result of overflow over the dam crest due to an unexpected rise in water level and failure of shut-off devices. In some cases, SHPPs contribute to the siltation of reservoirs and influence channel-forming processes.
There is a certain seasonality in electricity generation (noticeable declines in winter and summer), leading to the fact that in some regions small hydropower is considered as reserve (duplicate) generating capacity.
Among the factors hindering the development of small hydropower, most experts cite incomplete awareness of potential users about the benefits of using small hydropower facilities; insufficient knowledge of the hydrological regime and flow volumes of small watercourses; low quality of existing methods, recommendations and SNiPs, which causes serious errors in calculations; undeveloped methods for assessing and predicting possible impacts on the environment and economic activities; weak production and repair base of enterprises producing hydropower equipment for small hydropower plants, and mass construction of small hydropower facilities is possible only in the case of mass production of equipment, refusal of individual design and a qualitatively new approach to the reliability and cost of equipment - in comparison with old facilities withdrawn from operation.
Energy sources
Energy sources for small hydropower are:
* small rivers, streams,
* natural differences in heights on lake spillways and on irrigation canals of irrigation systems,
* technological watercourses (industrial and sewer discharges),
* differences in heights of drinking pipelines, water treatment systems and other pipelines designed for pumping various types of liquid products.
Easily. 1. TPP. Thermal Energy (electric) Stations. They are based on the processing (combustion) of solid fuel carriers, such as coal. Pros: 1. Large volume of electricity generation. 2. Most easy to operate. 3. The very principle of operation and their construction are very simple. 4. Cheap, easily available. 5. They provide jobs. Disadvantages: 1. They provide less electricity than hydroelectric power plants and nuclear power plants 2. They are environmentally dangerous - environmental pollution, the greenhouse effect, require the consumption of non-renewable resources (like coal). 3. Due to their primitivism, they are simply morally obsolete. HPP - Hydro Electric Station. Based on the use of water resources, rivers, tidal cycles. Pros: 1. Relatively environmentally friendly. 2. They provide many times more electricity than thermal power plants. 3. They can provide additional sub-production structures. 4. Workplaces. 5. Easier to operate than nuclear power plants. . Cons: 1. Again, environmental safety is relative (dam explosion, water pollution in the absence of a purification cycle, imbalance). 2. High construction costs. 3. They provide less energy than nuclear power plants. NPP - Nuclear Power Plants. The most advanced ES at the moment in terms of power level. Uranium rods of the uranium isotope -278 and the energy of an atomic reaction are used. Pros: 1. Relatively low resource consumption. The most important one is uranium. 2. The most powerful electricity generating plants. One power supply system can supply entire cities and megalopolises; the surrounding areas, in general, cover vast territories. 3. More modern than thermal power plants. 4. They provide a large number of jobs. 5. Open the way to creating more advanced electronic systems. Cons: 1. Constant pollution of the environment. Smog, radiation. 2. Consumption of rare resources - uranium. 3. Water use and pollution. 4. Possible threat of an ecological super catastrophe. In case of loss of control over nuclear reactions, violations of the cooling cycle (the clearest example of both errors is Chernobyl; the nuclear power plant is still closed with a sarcophagus, the worst environmental disaster in the history of mankind), external influence (earthquake, example - Fukushima), military attack or explosion by terrorists - an environmental catastrophe is very likely (or almost one hundred percent), and the threat of an explosion of a nuclear power plant is also very likely - this is an explosion, a shock wave, and most importantly, radioactive contamination of a vast territory, the echoes of such a catastrophe can hit the whole world. Therefore, a nuclear power plant is, along with WMD (Weapons of Mass Destruction), one of the most dangerous achievements of humanity, although a nuclear power plant is a Peaceful Atom. The first nuclear power plant was created in the USSR. The energy industry needs to be developed not only in the direction of using renewable resources, but also to develop more advanced types of energy systems, which will be fundamentally new in their basis and type of operation. Hypothetically, space exploration will soon begin, as well as penetration into other secrets of the microworld and, in general, physicists can give amazing results. Bringing nuclear power plants to maximum perfection is also a promising path for energy development. At this stage, of course, the most probable and feasible option is the development of wind turbine complexes, solar panels and IMPROVING hydroelectric power stations and nuclear power plants to maximum perfection.
Recently, as an alternative to classic medium-high-pressure dam hydroelectric power stations, low-pressure hydroelectric power stations operating on natural flow, which are quite widespread in Western Europe, have been actively proposed. Let's try to figure out what these hydroelectric power plants are and what their pros and cons are.
An example of a low-pressure run-of-the-river hydroelectric power plant is the Iffezheim hydroelectric power station on the Rhine, commissioned in 1978. Photo from here
The concept of a low-pressure run-of-river hydroelectric complex involves the creation of a hydroelectric power station on a flat river with a head of several meters, whose reservoir is usually located in the natural flood zone of the floodplain during heavy floods. Such waterworks have the following advantages:
* A small flood area, which usually does not include (or almost does not include) built-up lands. Consequently, no one needs to be resettled, and the impact on ecosystems is much less significant.
* It is much easier to integrate fish passages into low-pressure dams, and fish pass down through the turbines with less injury.
The Saratov hydroelectric power station is the lowest pressure one in the Volga-Kama cascade.
Now let's move on to the disadvantages:
* Such hydroelectric power stations form small reservoirs, suitable at best for daily flow regulation, or even operating on a watercourse. As a result, the production of such hydroelectric power plants is highly dependent on the season and weather conditions - during low-water periods it drops sharply.
* The efficiency of using the runoff of such hydroelectric power plants is much less than that of classical ones - not being able to accumulate runoff during high waters and floods, they are forced to empty a lot of water.
* Without a capacious reservoir, such hydroelectric systems cannot combat floods.
* From the point of view of navigation, the construction of several low-pressure hydroelectric complexes instead of one large one leads to an increase in time for locking - instead of one lock, you need to go through several.
* Low-pressure hydroelectric power plants have a significantly higher unit cost (calculated per kW of power and kWh of generated electricity). The lower the pressure, the larger the dimensions and, accordingly, the metal consumption of the equipment; the inability to accumulate runoff in the reservoir leads to the need to create more powerful culvert structures; several sluices are more expensive than one, etc. For comparison, we can cite the low-pressure Polotsk hydroelectric power station in Belarus and the high-pressure Boguchanskaya hydroelectric power station. The first costs approximately $4500 per kW, the second - about $1000 per kW. The difference, as we see, is 4.5 times.
Hydroelectric power station Tucurui in Brazil. In the Amazonian jungle, as in the Siberian taiga, large hydroelectric power plants are more efficient.
Let's summarize. The advantages of low-pressure hydroelectric power plants are most significant in densely populated areas, where the high cost of land and the large amount of work involved in relocating people, removing structures and infrastructure make large hydroelectric power stations with large reservoirs unacceptable. That is why low-pressure hydroelectric power plants are most widespread in Europe, where the population density is high and there are few own energy resources, which forces the use of all available hydro potential, albeit in expensive ways.
At the same time, in relatively sparsely populated regions, the advantages of large hydroelectric power stations are obvious - in fact, they are mostly being built there now all over the world (although the criteria for sparse population in different countries vary significantly, for China, with its billion-strong population, the resettlement of several tens of thousands of people is quite acceptable) .
Low-pressure run-of-river hydroelectric power plants do not compete with medium- and high-pressure hydroelectric power stations - each type of hydroelectric power station has its own “ecological niche” in which they are most effective. And references to run-of-the-river hydroelectric power stations in Western Europe when discussing hydropower projects in Eastern Siberia are a comparison of the incomparable.
Disadvantages of hydroelectric power plants
- Large reservoirs flood large areas of land that could be used for other purposes. Entire cities fell victim to reservoirs, causing mass displacement, discontent and economic hardship.
- The destruction or failure of a large hydroelectric dam almost inevitably causes a catastrophic flood downstream of the river.
- The construction of hydroelectric power stations is ineffective in lowland areas.
- Extended drought reduces and may even interrupt electricity production. Hydroelectric power station.
- The water level in artificial reservoirs is constantly and dramatically changing. There is no point in building country houses on their banks!
- The dam reduces the level of dissolved oxygen in the water because the normal flow of the river virtually stops. This can lead to the death of fish in the artificial reservoir and threaten plant life in and around the reservoir.
- The dam can disrupt the spawning cycle of fish. This problem can be combated by constructing fish ladders and fish lifts in the dam, or by moving fish to spawning grounds using traps and nets. However, this leads to an increase in the cost of construction and operation of hydroelectric power stations.
Question
Given all the problems of using fossil fuels and nuclear energy to produce electricity, why not build more hydroelectric power plants? There are a huge number of rivers in the world. Isn't it worth building as many hydroelectric power plants as possible?
Answer
Most of the sites for hydroelectric power plants are already in use. The number of dams and reservoirs that can be built on a river is limited. The energy taken by the power plant from the river can no longer be used downstream. If too many power plants are built on the river, economic conflicts related to energy distribution are inevitable.