Electricity generation is the process of generating electrical energy from primary energy sources. For electricity companies, it is the first process in the delivery of electricity to consumers. Other processes, such as transmission, distribution, energy storage and recovery using pumped storage methods, are usually carried out by the electrical industry. Electricity is most often generated in a power plant by electromechanical generators, mainly driven by thermal motors fed by nuclear fission or combustion, but also by other means such as the kinetic energy of running water and wind. Other sources of energy are photovoltaic solar energy and geothermal energy.
The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by British scientist Michael Faraday. This method is still used today: electricity is generated by the movement of a wire loop, or copper disk between the poles of a magnet. Power plants became economically practical with the development of AC power transmission, using power transformers to transmit power at high voltage and low loss. Electricity has been generated at the central stations since 1882. The first power plants run on hydraulic power or coal, and today rely mainly on coal, nuclear, natural gas, hydroelectric, wind generators, and oil, with quantities Supplementary solar energy, tide Energy and geothermal sources. The use of power lines and power poles has been very important in the distribution of electricity.
The selection of modes of electricity production and their economic viability varies according to demand and the region. The economy varies considerably across the world, resulting in generalized selling prices, eg. The price in Venezuela is 3 cents per kWh while in Denmark it is 40 cents per kWh. Hydroelectric plants, nuclear power plants, thermal power stations and renewable sources have their own pros and cons, and the selection is based on local energy demand and fluctuations in demand. All electrical grids have varying loads on them but the daily minimum is the base load, supplied by continuously operating plants. Nuclear, coal, oil and gas plants can supply base load.
Thermal energy is economical in areas of high industrial density, as high demand can not be met by renewable sources. The effect of localized contamination is also minimized, as industries are often located away from residential areas. These plants can also withstand variations in load and consumption by adding more units or temporarily decreasing the production of some units. Nuclear power plants can produce an enormous amount of energy from a single unit. However, recent disasters in Japan have raised concerns about the safety of nuclear energy, and the cost of capital of nuclear plants is very high. Hydroelectric power plants are located in areas where potential energy from water fall can be harnessed for moving turbines and power generation. It is not an economically viable source of production where the load varies greatly during the annual production cycle and the capacity to store the water flow is limited.
Due to advances in technology, and with mass production, renewable sources other than hydroelectricity (solar energy, wind energy, tidal power, etc.) experienced decreases in the cost of production and energy is now in Many cases comparing costs with fossil fuels. Many governments around the world provide subsidies to offset the higher cost of any new energy production and to make the installation of renewable energy systems economically possible. However, their use is often limited by their intermittent nature. If natural gas prices are less than $ 3 per million British thermal units, the generation of electricity from natural gas is cheaper than the generation of energy by burning coal.