The power system consists of plants from various energy sources, transmission lines, and distribution lines. Each of these components may have environmental impacts at various stages of development and use within their construction, during the generation of electricity, and in its decommissioning and disposal. We can divide this impact into operational impacts (fuel sources, global and local atmospheric pollution) and construction impacts (manufacturing, installation, decommissioning and disposal). This page only sees the operational environmental impact of a power plant . This page is governed by energy sources and includes impacts such as water use, emissions, local pollution, and wildlife migration.
More detailed information on the impact of electricity generation for specific technologies and other environmental impacts of electrical power systems can generally be found under Category: Environmental impacts of the energy industry.
Video Environmental impact of electricity generation
Water use
The use of water is one of the most obvious environmental impacts of electricity generation. All thermal cycles (coal, natural gas, nuclear, geothermal, and biomass) use water as a coolant to induce a thermodynamic cycle that allows electricity to be extracted from heat energy. Other energy sources such as wind and solar use water to clean the equipment, while hydroelectrics have water use from the evaporation of the reservoir. The amount of water use is often a big concern for power generation systems as population increases and drought is a concern. In addition, changes in water resources can affect the reliability of power plants. The electricity sector in the United States attracts more water than other sectors and is heavily dependent on available water resources. According to the US Geological Survey, in 2005, withdrawal of geothermal power plants accounted for 41 percent (201 BILL/d) of all freshwater withdrawals. Almost all water drawn for thermoelectric power is surface water that is used for once-through cooling in power plants. Withdrawals for irrigation and public supply in 2005 were 37% and 13% of all freshwater withdrawals. Possible future trends in water consumption are discussed here.
Discussion of water use of power plants distinguishes between water withdrawal and water consumption. According to the USGS, "withdrawal" is defined as the amount of water discharged from the ground or diverted from a water source to be used, while "consumption" refers to the amount of water vaporized, occurring, incorporated into the product or plant, or otherwise removed from the direct water environment. Both water consumption and consumption are important environmental impacts to be evaluated.
The common numbers for the use of fresh water from different resources are shown below.
Steam power plants (nuclear, coal, NG, solar thermal) require plenty of water for cooling, to remove heat on the condenser vapor. The amount of water required relative to the output of the plant will decrease as the boiler temperature increases. Coal and gas-fired boilers can produce high and more efficient steam temperatures, and require less cooling water relative to output. The nuclear boiler is limited in the temperature of the vapor by material constraints, and the sun is limited by the concentration of the energy source.
Thermal cycling plants near the ocean have the option of using seawater. Such sites will not have cooling towers and will be much less constrained by environmental problems than exhaust temperatures because heat dissipation will have very little effect on water temperatures. It also will not spend the water available for other uses. Nuclear power in Japan for example, does not use cooling towers at all because all the plants are located on the beach. If a dry cooling system is used, significant water from the water table will not be used. Other, newer, existing cooling solutions exist, such as waste cooling at the Palo Verde Nuclear Generating Station.
The main cause of hydroelectric water use is evaporation and seepage into the water table.
References: Nuclear Energy Institute fact sheets use EPRI data and other sources.
Source (s): Adapted from the US Department of Energy, Energy Demand on Water Resources. Report to Congress on Energy and Water Interdependence, December 2006 (except where noted) * Cambridge Energy Research Associates (CERA) estimates. Estimated #Educated.
Water requirements for existing and emerging termoelectric plant technologies. US Department of Energy, National Energy Technology Laboratory, August 2008 Note (s): 3.6 GJ = gigajoule (s) == 1 MWÃ, Â · h = megawatt-hour (s), so 1 L/GJ = 3.6 L/MWÃ, Â · h. BÃ ¢ = Ã, Coal black (supercritical) - (new subcritical), BrÃ, = Coal brown (new subcritical), HÃ, = HardÃ, coal, LÃ, = Lignite, cc = combined cycle, ocÃ, = Ã, open cycle, T L Ã, = low temperature/closed circuit (geothermal doublet), T H Ã, = high temperature/open circuit.
Maps Environmental impact of electricity generation
Fossil fuels
Most of today's electricity is generated by burning fossil fuels and producing steam which is then used to drive a steam turbine which, in turn, drives an electric generator.
Such systems allow electricity to be generated where needed, since fossil fuels can be easily transported. They also utilize a large infrastructure designed to support consumer cars. The supply of world fossil fuels is large, but limited. Low cost fossil fuel exhaust will have significant consequences for energy sources as well as for plastics manufacturing and many other things. Various estimates have been calculated when exactly will be exhausted (see Peak oil). New sources of fossil fuels continue to be discovered, although discovery rates slow as temporary difficulties of extraction simultaneously increase.
More serious is the concern about emissions resulting from burning fossil fuels. Fossil fuels form a significant repository of carbon buried deep underground. Burning them results in converting this carbon into carbon dioxide, which is then released into the atmosphere. Estimated CO2 emissions from the world's electric power industry is 10 billion tons per year. This results in an increase in atmospheric carbon dioxide levels on Earth, which increases the greenhouse effect and contributes to global warming. The link between increased carbon dioxide and global warming is well received, although fossil fuel producers are eagerly opposed to this finding.
Depending on certain fossil fuels and combustion methods, other emissions may be generated as well. Ozone, sulfur dioxide, NO 2 and other gases are often released, as well as particles. Sulfur and nitrous oxide contribute to smog and acid rain. In the past, plant owners overcame this problem by building a very high exhaust pile, so pollutants would be diluted in the atmosphere. While this helps reduce local contamination, it does not help at all with global issues.
Fossil fuels, especially coal, also contain aqueous radioactive material, and burn enormous amounts of this material release into the environment, leading to low levels of local and global radioactive contamination, which, ironically, is higher than station nuclear power as a contaminant Their radioactivity is controlled and stored.
Coal also contains traces of toxic heavy elements such as mercury, arsenic and others. Mercury evaporated in a power plant boiler can remain suspended in the atmosphere and circulate around the world. While large quantities of mercury are present in the environment, as other manmade mercury emissions become more controlled, the emission of power generation becomes a significant part of the remaining emissions. Mercury power generation in the United States is estimated at about 50 tons per year in 2003, and several hundred tons per year in China. Power plant designers can adapt the equipment to a power plant to reduce emissions.
Menurut Environment Canada:
"The power sector is unique among industry sectors in the enormous contribution to emissions associated with virtually any air problem.Power generates large parts of Canadian nitrogen oxide and sulfur dioxide emissions, which contribute to smog and acid rain and the formation of fines. particles are the largest source of uncontrolled industrial mercury emissions in Canada. Fossil fuel-fueled fuels also emit carbon dioxide, which can contribute to climate change. In addition, the sector has a significant impact on water and habitats and species. , hydro dams and transmission lines have a significant impact on water and biodiversity. "
The practice of coal mining in the United States also includes strip mining and removal of mountain peaks. Tailings tailings are dumped and disposed of into local rivers and produce most or all of the rivers in coal-producing areas to walk throughout the red year with sulfuric acid that kills all life in the river.
The efficiency of some of these systems can be improved by cogeneration and geothermal methods (combined heat and power). The steam process can be extracted from a steam turbine. The heat wastes generated by thermal generating stations can be used for heating the rooms of nearby buildings. By combining the production of electricity and heating, less fuel is consumed, thereby reducing the environmental effects compared to separate heat and power systems.
Switch from fuel to electricity
The electric car does not burn petroleum, thus shifting any environmental impact from car users to electric utilities. In South Africa electric cars, will be powered by coal-generated electricity and damage the environment. In Norway electric cars will be powered by hydroelectric and harmless. The electric car itself is not profitable or dangerous, it depends how your area generates electricity.
Homeowners can get 90% efficiency using natural gas to heat their homes. Heat pumps are very efficient and do not burn natural gas, shifting the environmental impact from homeowners to electric utilities. Switching from natural gas to electricity in Alberta Canada burns natural gas and coal with an efficiency of about 40% to supply heat pumps. In Quebec Canada where heating of electrical resistance is common, heat pumps will use 70 percent fewer hydroelectric power plants. Heat pumps may be beneficial to the environment or not, it depends on how your region generates electricity.
Nuclear power
Nuclear power plants do not burn fossil fuels so they do not directly emit carbon dioxide; because of the high energy output of nuclear fuel, the carbon dioxide emitted during mining, enrichment, fabrication and transport of fuel is small compared to the carbon dioxide emitted by fossil fuels from the same energy yield.
Large nuclear power plants can resist heat wasted into natural water bodies; this may cause an increase in undesirable water temperature with adverse effects on aquatic life.
Radioactivity emissions from nuclear plants are controlled by regulation. Abnormal surgery can cause the release of radioactive material on a scale ranging from mild to severe, although this scenario is very rare.
The mining of uranium ore could disrupt the environment around the mine. The disposal of controversial fuel, with many of the proposed long-term storage schemes under intense scrutiny and criticism. The transfer of new or used fuels to weapons production represents the risk of nuclear proliferation. Finally, the reactor structure itself becomes radioactive and will require decades of storage before it can be economically dismantled and in turn disposed of as waste.
Renewable energy
Renewable power technologies can have significant environmental benefits. Unlike coal and natural gas, they can generate electricity and fuel without releasing large amounts of CO2 and other greenhouse gases that contribute to climate change, but greenhouse gas savings from a number of biofuels have been found far less than anticipated, as discussed in the article The impact of indirect land use change from biofuels.
The sun and wind have been criticized from an aesthetic point of view. However, the methods and opportunities exist for spreading this renewable technology efficiently and unobtrusively: solar collectors can still double as noise barriers along the highway, and large roads, parking lots, and roof areas are currently available; Amorphous photovoltaic cells can also be used to color the windows and generate energy. Renewable energy advocates also argue that current infrastructure is less aesthetic than alternatives, but lies farther from the views of most critics.
Hydroelectric
The main advantage of conventional hydroelectric dams with reservoirs is their ability to store potential power for later electricity production. The combination of energy supply and natural production on demand has made hydro power the largest source of renewable energy so far. Other benefits include longer lifespan than fuel-generated plants, lower operating costs, and provision of facilities for water sports. Some dams also operate as pump-storage plants balancing supply and demand in the generation system. Overall, hydroelectric power can be cheaper than electricity generated from fossil fuels or nuclear energy, and areas with abundant hydropower attract industry.
However, in addition to the above advantages, there are some disadvantages to the dam that make large reservoirs. These may include: dislocation of people living where reservoirs are planned, release of large amounts of carbon dioxide in construction and flooding of reservoirs, disruption of aquatic ecosystems and bird life, adverse impacts on river environments, potential risk of sabotage and terrorism. , and in rare cases of catastrophic failure from dam walls.
Some dams only generate electricity and serve no other purpose, but in many places, large reservoirs are needed for flood control and/or irrigation, adding hydroelectric parts is a common way to pay for new reservoirs. Flood control protects life/property and irrigation supports agricultural enhancement. Without an electric turbine, the downstream river environment will improve in some way, but dams and reservoir concerns will remain unchanged.
Small hydro and run-of-the-river are two low impact alternatives to hydroelectric reservoirs, although they can generate intermittent power due to lack of stored water.
Tidal
Tidal turbines
Constricting land such as straits or inlets can create high speeds in certain locations, which can be captured using turbines. This turbine can be horizontal, vertical, open, or channeled and usually placed near the bottom of the water column.
The main concern of the environment with tidal energy is associated with knife attacks and entanglement of marine organisms because high-speed water increases the risk of organisms being pushed near or through this device. Like all offshore renewable energy, there are also concerns about how EMF creation and acoustic output can affect marine organisms. Since the device is in water, the acoustic output can be greater than that created with offshore wind energy. Depending on the frequency and amplitude of sound generated by tidal energy devices, these acoustic outputs can have varying effects on marine mammals (especially those that echolocate to communicate and navigate in marine environments such as dolphins and whales). Elimination of receding energy can also cause environmental problems such as lowering the quality of farfield water and disrupting the sediment process. Depending on the size of the project, this effect can range from small traces of sediments built near tidal devices to greatly affect coastal ecosystems and processes.
Tidal storm
Tidal storms are dams built at entrances to bays or estuaries that capture the potential of tidal energy with turbines similar to conventional hydrokinetic dams. Energy is collected while differences in altitude on both sides of the largest dam, at low tide or high. A minimum height fluctuation of 5 meters is required to justify the construction, so that only 40 locations around the world have been identified feasible.
Dam installation can change the shoreline inside the bay or estuary, affecting large ecosystems that depend on tidal plains. Inhibiting the flow of water into and out of the bay, there may also be a little flushing of the bay or estuary, causing additional turbidity (less suspended solids) and less salt water, which can result in the death of fish acting as an important food source. for birds and mammals. Fish migrations also can not access breeding flows, and may try to bypass the turbines. The same acoustic problem applies to tidal dams. A reduction in shipping accessibility can be a socio-economic problem, although keys can be added to allow for slower roads. However, dams can improve local economies by increasing access to land as bridges. Calmer water also allows better recreation in the bay or estuary.
Biomass
Electricity can be generated by burning anything that will burn. Some of the electricity generated by the burning of plants grown specifically for the purpose. Usually this is done by fermenting plant material to produce ethanol, which is then burned. This can also be done by letting organic matter decay, producing biogas, which is then burned. Also, when burned, wood is a form of biomass fuel.
Biomass burning generates much of the same emissions as burning fossil fuels. However, biomass growth captures carbon dioxide from the air, resulting in a net contribution to the small global atmospheric carbon dioxide level.
The biomass growth process is subject to the same environmental problems as every type of farm. It uses a large amount of land, and fertilizers and pesticides may be necessary for cost-effective growth. The biomass produced as a by-product of agriculture shows some promise, but most of the biomass is currently used, to plow back to the soil as fertilizer if nothing else.
Wind power
Ground wind
Wind power utilizes mechanical energy from the constant flow of air above the earth's surface. Wind power plants generally consist of wind farms, the field of wind turbines in locations with relatively high winds. The main publicity issue about wind turbines is their older predecessors, such as the Altamont Pass Mountain Field in California. The older and smaller wind turbines are rather noisy and crowded, making them very unattractive to the locals. The windward side against the wind from the turbine does not disrupt the local low-level winds. Modern large wind turbines have reduced this concern, and have become a commercially important source of energy. Many homeowners in areas with high winds and expensive electricity set up small wind turbines to reduce their electricity bills.
Modern wind farming, when installed on farmland, has one of the lowest environmental impacts of all energy sources:
- It occupies less space per kilowatt-hour (kWh) of electricity generated than other renewable energy conversion systems, and is compatible with grazing and crops.
- Generates energy used in its construction in just a few months of operation.
- The greenhouse gas emissions and the air pollution generated by the construction are small and declining. No emissions or pollution generated by its operation.
- Modern wind turbines spin very slowly (in terms of rounds per minute) that they are rarely harmful to birds.
Landscaping and legacy issues can be a significant problem for certain wind farms. However, when proper planning procedures are followed, the risk of heritage and landscape should be minimal. Some may still object to wind farms, perhaps on aesthetic basis, but there are still supportive opinions from the wider community and the need to address the threat posed by climate change.
Offshore wind
Offshore winds are similar to terrestrial wind technologies, such as large wind turbines located in freshwater or saltwater environments. The wind causes the blade to spin, which then turns into electricity and is connected to the grid by cable. The advantage of offshore winds is that the wind is stronger and more consistent, allowing turbines of a much larger size to be built by ships. The disadvantage is the difficulty of placing structures in a dynamic marine environment.
Turbines are often a wider version of existing land technologies. However, the foundations are unique to offshore wind and are listed below:
Monopile foundation
The monopile foundation is used in shallow depth applications (0-30 m) and consists of piles that are pushed to various depths to the seabed (10-40 m) depending on soil conditions. The piling buildup process is an environmental problem because the noise generated is very loud and propagates deep in water, even after mitigation strategies such as bubble shield, slow start, and acoustic coating. The tracks are relatively small, but may still cause scouring or artificial corals. The transmission line also produces electromagnetic fields that may be harmful to some marine organisms.
Under fixed tripod
The bottom base of the tripod is used in transitional depth applications (20-80 m) and consists of three legs connecting to the central shaft supporting the turbine base. Each leg has a pile pushed to the seafloor, though less depth is required due to the vast foundation. The environmental impact is a combination of them for monopoly and gravity foundations.
Gravity Foundation
The gravity foundation is used in shallow depth applications (0-30 m) and consists of large and heavy bases made of steel or concrete to rest on the seafloor. The tracks are relatively large and can cause scouring, artificial reefs, or physical destruction of the habitat at the time of introduction. The transmission line also produces electromagnetic fields that may be harmful to some marine organisms.
Gravity tripod
The gravity tripod foundation is used in transitional depth applications (10-40 m) and consists of two heavy concrete structures connected by three feet, one seated structure on the seabed while the other is above the water. In 2013, there is no offshore windfarm currently using this foundation. Environmental concerns are identical to gravity foundations, although scouring effects may be less significant depending on the design.
Floating structure
The foundation of the buoyant structure is used in deep application (40-900 m) and consists of a balanced floating structure moored to the seabed with fixed wires. Floating structures can be stabilized using buoyancy, mooring lines, or ballasts. Mooring lines can cause small scours or potential collisions. The transmission line also produces electromagnetic fields that may be harmful to some marine organisms.
Geothermal power
Geothermal energy is Earth's heat, which can be utilized to generate electricity in power plants. Warm water generated from geothermal sources can be used for industry, agriculture, bathing and cleaning. Where the source of underground steam can be tapped, steam is used to run steam turbines. The source of geothermal steam has a limited life because the underground water has run out. Settings that circulate surface water through rock formations to produce hot water or steam, on a time scale relevant to humans, can be updated.
While a geothermal power plant does not burn any fuel, it will still have emissions due to substances other than steam emerging from geothermal wells. These may include hydrogen sulfide, and carbon dioxide. Some geothermal steam sources contain an insoluble mineral that must be removed from the vapor before being used for generation; this material should be disposed of properly. Steam power plants (closed cycle) require cooling water for condensers; the transfer of cooling water from natural sources, and rising temperatures when returning to rivers or lakes, may have a significant impact on local ecosystems.
Eliminating groundwater and accelerating the cooling of rock formations can cause earth tremor. Improved geothermal system (EGS) underground rock fracture to produce more steam; Such projects can cause earthquakes. Certain geothermal projects (such as one near Basel, Switzerland in 2006) have been suspended or canceled due to unpleasant earthquakes caused by geothermal recovery. However, the risks associated with "hydrofracturing induced crunch are low compared to natural earthquakes, and can be mitigated by careful management and monitoring" and "should not be considered a barrier to further development of Rock Hot geothermal energy sources".
Solar power
Currently photovoltaic solar power is used mainly in Germany and Spain where the government offers financial incentives. In the US, the State of Washington also provides financial incentives. Photovoltaic power is also more common, as expected, in areas where sunlight is abundant.
It works by converting solar radiation into direct current power (DC) by using photovoltaic cells. This power can then be converted into a more common AC power and fed to the power grid.
Solar photovoltaic solar offers a viable alternative to fossil fuels for cleanliness and supplies, albeit at high production costs. Future technological improvements are expected to bring these costs into a more competitive range.
The negative impact on the environment lies in the creation of solar cells made primarily of silica (from sand) and silicon extraction from silica may require the use of fossil fuels, although newer manufacturing processes have eliminated CO 2 production. Solar power brings the initial cost to the environment through production, but offers clean energy over the life span of solar cells.
Large-scale power plants using photovoltaic power require very large land, due to low photovoltaic power density. Land use can be reduced by installing on buildings and other constructed areas, although this reduces efficiency.
Solar power is concentrated
Also known as solar thermal, this technology uses different types of mirrors to concentrate sunlight and generate heat. This heat is used to generate electricity in standard Rankine cycle turbines. Like most thermoelectric power plants, it consumes water. This can be a problem, as most solar power plants are in desert environments because of the huge amount of sun and land needs. Many concentrated solar systems also use exotic fluid to absorb and collect heat while remaining at low pressure. This liquid can be dangerous if spilled.
Power
The strength of negawatts refers to investments to reduce electricity consumption rather than invest to increase supply capacity. In this way, investment in Negawatt can be considered as an alternative to new power plants and the costs and environmental problems can be compared.
Alternative investments negawatt to reduce consumption by increasing efficiency include:
- Provide customers with energy-efficient lighting - low environmental impact
- Increased heat insulation and airtight for buildings - low environmental impact
- Replacing old industrial plants - low environmental impacts. Can have a positive impact due to reduced emissions.
Alternative investments negawatt to reduce the peak electrical load with a shift in demand time include:
- Heater storage - old system has asbestos. The newer systems have a low environmental impact.
- A demand response control system in which an electrical board can control a particular customer's burden - minimal environmental impact
- Thermal storage systems such as ice storage systems to make ice at night and store them for use in air conditioning during the day - minimal environmental impacts
- Hydroelectricity hydroelectric pumped - can have significant environmental impact - see Hydroelectric
- other Grid energy storage technologies - impacts vary
Note that the time transfer does not reduce total energy consumption or system efficiency; However, it can be used to avoid the need to build new power plants to cope with peak loads.
See also
- Air pollution
- Alta Controversy
- Carbon Principles
- Cost of electricity by source - including environmental and health costs
- EKOenergy - ecolabel for electricity managed by environmental NGO
- Environmental impacts of the energy industry
- Eugene Green Energy Standard
- Flue gas desulfurization
- Exhaust emissions from burning fossil fuels
- Fossil fuel power plants
- Life-cycle greenhouse gas emissions from energy sources
- List of countries with electricity production from renewable sources
- List of energy storage projects
- Nuclear power
- The nuclear reporter
- Power plant
- Scientific opinion on climate change
References
External links
- Who's Afraid of Nuclear Power? - ABC Australia - 4 Corners - Historical International Nuclear Energy Policy, Trends & amp; Debate
Source of the article : Wikipedia
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