Power generation is the process of generating electricity from primary energy sources. For electric utilities in the power industry, it is the first stage in the delivery of electricity to end users, the other stage is the transmission, distribution, energy storage and recovery, using pumped storage method.
The electrical characteristic is that it is not the primary energy that is freely present in nature in tremendous quantities and it must be produced. Production is done in power plants. Electricity is most often generated at power plants by electromechanical generators, driven primarily by heat engines triggered by burning or nuclear fission but also in other ways such as kinetic energy from running water and wind. Other energy sources include solar photovoltaic and geothermal power.
Video Electricity generation
History
The basic principles of power generation were discovered in the 1820s and early 1830s by the English scientist Michael Faraday. The method, which is still used today, is for the electricity generated by the circular motion of the wire, or the copper disk between the magnetic poles. The power plant became economically viable with the development of an AC power transmission, using a power transformer to transmit power at high voltage and with low losses.
In 1870, commercial power production began with a dynamo coupling to a hydraulic turbine. In 1870, mechanical production of electric power began the Second Industrial Revolution and created the invention using energy, whose main contributors were Thomas Alva Edison and Nikola Tesla. Previously the only way to generate electricity was by chemical reaction or using battery cells, and the only practical use of electricity was for telegraph.
Power generation at the central power station began in 1882, when a steam engine that drives the dynamo at Pearl Street Station produces a DC current that lights a public light on Pearl Street, New York. This new technology is quickly adopted by many cities around the world, which adopt their gas-fueled street lamps for electric power, and as soon as electric lights will be used in public buildings, in business, and to drive public transport, such as trams and train.
The first power plant uses hydro power or coal; and currently various energy sources are used, such as coal, nuclear, natural gas, hydroelectricity, wind generators, and oil, as well as solar energy, tidal power, and geothermal resources. The use of power lines and power lines is very important in the distribution of electricity.
Maps Electricity generation
Method generate electricity
There are several fundamental methods for converting other forms of energy into electrical energy. The triboelectric effect, the piezoelectric effect, and even directly capture the Betavoltaics nuclear decay energy used in niche applications, such as direct conversion from heat to electric power in the thermoelectric effect. The scale of the utility scale is done by turning the electric generator, or by a photovoltaic system. A small portion of the electric power distributed by the utility is provided by the battery.
Generator
Electric generators convert kinetic energy into electricity. This is the most commonly used form to generate electricity and is based on Faraday's law. This can be seen experimentally by rotating the magnet in a closed loop of a conducting material (eg a copper wire). Almost all commercial power plants are conducted using electromagnetic induction, where mechanical energy forces the generator to rotate.
Electrochemical
Electrochemistry is the direct transformation of chemical energy into electricity, as in battery. Electrochemical power plants are important in portable and mobile applications. Currently, most of the electrochemical power comes from the battery. Primary cells, such as common zinc-carbon batteries, act as power sources directly, but secondary cells (ie rechargeable batteries) are used for storage systems rather than primary generation systems. The open electrochemical system, known as fuel cell, can be used to extract electricity from either natural fuel or from synthesized fuel. Osmotic power is likely in places where salt and fresh water converge.
Photovoltaic effects
The photovoltaic effect is the transformation of light into electrical energy, as in solar cells. The photovoltaic panel converts sunlight directly into electricity. Although sunlight is free and abundant, solar electricity is usually still more expensive to produce than mechanically generated power on a large scale due to panel costs. The low-efficiency silicon solar cells have decreased in cost and multijunction cells with nearly 30% conversion efficiency now commercially available. More than 40% efficiency has been demonstrated in the experimental system. To date, photovoltaic is most often used in remote locations where there is no access to commercial power grids, or as an additional source of electricity for individual homes and businesses. Recent advances in manufacturing efficiency and photovoltaic technology, combined with environmentally driven subsidies, have dramatically accelerated the deployment of solar panels. The installed capacity grew by 40% per year led by an increase in Germany, Japan, and the United States.
Power generation and production economics
The selection of the mode of electricity production and economic feasibility varies according to demand and region. Economies vary widely around the world, resulting in widespread selling prices, eg. the price in Venezuela is 3 cents per kWh while in Denmark it is 40 cents per kWh. Hydroelectric power plants, nuclear power plants, thermal power plants and renewable resources have their pros and cons, and the selection is based on local power requirements and demand fluctuations. All power lines have varying loads but daily minimums are basic loads, supplied by continuous running plants. Nuclear, coal, oil and gas plants can supply basic loads.
Thermal energy is economical in areas with high industrial density, because high demand can not be fulfilled by renewable sources. Local pollution effects are also minimized because the industry is usually located away from residential areas. This plant can also withstand load and consumption variations by adding more units or temporarily decreasing the production of several units. Nuclear power plants can generate large amounts of power from one unit. However, recent disasters in Japan have raised concerns over nuclear power security, and the capital cost of nuclear plants is very high. The hydroelectric power station is located in an area where the potential energy of falling water can be utilized to drive turbines and power plants. It is not an economically viable source of production where the load varies too much during the annual production cycle and the ability to store limited water flow.
Due to technological advances, and with mass production, renewable sources in addition to hydropower (solar power, wind energy, tidal power, etc.) are experiencing a decrease in production costs, and energy is now in many cases a cost comparison with fossil fuels. Many governments around the world are subsidizing to keep up with the higher cost of new power production, and to make the installation of an economically viable renewable energy system. However, its use is often limited by its intermittent nature. If the price of natural gas is below $ 3 per million UK thermal units, generating electricity from natural gas is cheaper than generating electricity by burning coal.
Generate equipment
Turbine
Nearly all of the commercial electricity power on Earth is generated with turbines, driven by wind, water, steam or gas combustion. The turbine drives the generator, thus converting mechanical energy into electrical energy by electromagnetic induction. There are many different methods for developing mechanical energy, including heat engines, hydropower, wind power and tidal. Most power plants are driven by hot engines. Fossil fuel combustion supplies most of the energy to this machine, with a significant fraction of nuclear fission and some from renewable sources. Modern steam turbines (invented by Sir Charles Parsons in 1884) currently produce about 80% of the world's electricity using a variety of heat sources. Types of turbines include:
- Steam
- Water is boiled by burned coal in a thermal power plant, about 41% of all electricity is generated in this way.
- The heat of nuclear fission made in nuclear reactors creates steam. Less than 15% of electricity is generated in this way.
- Renewable. Steam is produced by Biomass, the solar thermal energy in which the parabolic troughs of the sun and solar towers concentrate sunlight to heat the heat transfer fluid, which is then used to produce steam, or geothermal power.
- Natural gas: turbines are driven directly by the gas produced by combustion. The combined cycle is driven by steam and natural gas. They generate power by burning natural gas in a gas turbine and using residual heat to produce steam. At least 20% of the world's electricity is generated by natural gas.
- Water energy is captured from water movement. From falling water, ups and downs of tidal currents or thermal currents of the oceans. Each riding a water turbine generates about 16% of the world's electricity.
- The windmill is a very early wind turbine. In the solar updraft tower winds are produced artificially. Before 2010 less than 2% of the world's electricity is generated from the wind.
Although the most common turbines in commercial power plants, smaller generators can be powered by gasoline or diesel engines. This can be used to support an isolated generation or village.
Generator
Electrical generators are known in the simplest form of the invention of electrically magnetic induction in the 1830s. In general, some of the major driving shapes such as the engine or turbine described above, propel the magnetic field to rotate through the stationary coil of the wire thereby converting mechanical energy into electricity. The enormous 2000 MW (2,682,000 horsepower) unit designed by Siemens was built for unit 3 in the Olkiluoto Nuclear Power Plant. The only scale of commercial electricity production that does not use a generator is solar PV.
Production
Electricity production in 2013 is 23.322TWh. Power source is coal and peat 41%, natural gas 22%, hydroelectric 16%, nuclear power 11%, oil 4%, biomass and waste 2% and other sources 4%. Other sources include wind, geothermal, solar photovoltaic, and solar thermal.
- IEA/OECD data source
Total energy consumed in all power plants for power generation is 4,398,768 ktoe (kilo ton of oil equivalent) which is 36% of total primary energy source (TPES) in 2008.
The output of electricity (gross) is 1,735,579 ktoe (20,185 TWh), efficiency is 39%, and the remaining 61% is generated by heat. A small portion (145,141 ktoe, which represents 3% of total input) of heat is used on thermal power plants and thermal power plants. Electricity consumption and electrical transmission losses at home are 289,681 ktoe. The amount supplied to final consumers is 1,445,285 ktoe (16,430 TWh), which accounts for 33% of the total energy consumed in power plants and thermal power generation and power generation (CHP).
Historical results of electricity production
Production by country
The United States has long been the largest producer and consumer of electricity, with its global share in 2005 at least 25%, followed by China, Japan, Russia and India. In January-2010, the total power plants for the 2 largest generators are as follows: US: 3992 billion kWh (3992 TWh) and China: 3715 billion kWh (3715 TWh).
List of countries with 2008 power sources
The data source value (electric power generated) is the IEA/OECD. The listed countries are the top 20 by population or top 20 according to GDP (PPP) and Saudi Arabia based on CIA World Factbook 2009.
Solar PV * is Photovoltaics Other Bio * = 198TWh (Biomass) 69TWh (Waste) 4TWh (other)
Environmental issues
Variations between countries produce electrical power affecting environmental concerns. In France only 10% of electricity generated from fossil fuels, the US is higher at 70% and China 80%. Electrical cleanliness depends on the source. Most scientists agree that pollutant emissions and greenhouse gases from fossil fuel power plants are responsible for most of the world's greenhouse gas emissions; in the United States, power generation accounts for nearly 40% of emissions, the largest of any source. Transport emissions are behind, accounting for about a third of US carbon dioxide production. In the United States, the burning of fossil fuels for power generation is responsible for 65% of all emissions of sulfur dioxide, a major component of acid rain. Power generation is the combined source of NOx, carbon monoxide, and the fourth highest particulate material in the US. In July 2011, the British parliament filed a motion that "the level of carbon emissions from nuclear power is about three times lower per kilowatt hour compared to diesel, four times lower than clean coal and 36 times lower than conventional coal."
See also
References
Source of the article : Wikipedia
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