Michael Faraday conducted early research on electricity generation in the 1820s and early 1830s. His method, which is still employed today, involves using magnetic poles to generate electricity by moving a loop of wire or copper disc. [1] This technique serves as the initial stage for electric utilities to distribute electricity to consumers.
The electrical power industry commonly deals with tasks like electric power transmission, electricity distribution, and electrical power storage/recovery using pumped storage methods. Power stations typically produce electric power by utilizing electromechanical generators fueled mainly by heat engines powered by chemical combustion or nuclear fission. However, alternative sources such as the kinetic energy of flowing water and wind can also be harnessed.
Electricity generation utilizes various technologies, such as solar photovoltaics and geothermal power. In France, nuclear power was the main source of electricity in 2006.[3] The use of alternating current power lines facilitated efficient long-distance electricity transportation through power transformers, which helped advance centralized power generation.
Since 1881, electricity has been generated at central stations. Initially, these power plants were operated using water power or coal. However, today we primarily depend on coal, nuclear, natural gas, hydroelectric, and petroleum for generating electricity. Additionally, a small portion of our energy comes from solar energy, tidal harnesses, wind generators, and geothermal sources. [edit] Methods of generating electricity
There are seven primary ways to directly convert other forms of energy into electrical energy. These include static electricity, which involves the physical separation and movement of electric charge, such as the triboelectric effect and lightning. Electromagnetic induction is another method, in which kinetic energy is transformed into electricity through devices like generators and alternators. Electrochemistry converts chemical energy into electricity, seen in batteries, fuel cells, and nerve impulses. The photoelectric effect changes light into electrical energy, as seen in solar cells. The thermoelectric effect converts temperature differences into electricity using thermocouples and thermopiles. The piezoelectric effect transforms mechanical strain from electrically anisotropic molecules or crystals. Nuclear transformation involves creating and accelerating charged particles, such as betavoltaics or alpha particle emission.
The discovery of static electricity was the first and it remains used today in devices like the Van de Graaff generator and MHD generators. In this process, electrons are mechanically separated and transported to increase their electric potential. Electromagnetic induction is the most common method in commercial electrical generation, where mechanical energy forces a generator to rotate. Different methods are used to develop this mechanical energy, including heat engines, hydroelectric power , wind power ,tidal power .
The conversion of nuclear energy to electricity through beta decay is only used on a small scale. In a full-size nuclear power plant, the heat from a nuclear reaction powers a heat engine that drives a generator. This generator converts mechanical energy into electricity using magnetic induction. Heat engines are the primary drivers of electric generation, with most of the heat originating from burning fossil fuels. Some heat is obtained from nuclear fission and renewable sources. The modern steam turbine, invented by Sir Charles Parsons in 1884, now generates approximately 80% of global electric power by utilizing various heat sources.
China’s Three Gorges Dam, one of the largest dams in the world, is capable of producing a substantial amount of hydroelectric power with a capacity of 22.5 GW. Another power plant known as Susquehanna Steam Electric Station is situated near Orem, Utah and operates as a nuclear facility. Additionally, there is also a combined cycle natural gas power plant in the same vicinity. These power plants utilize turbines that are powered by an intermediate energy carrier fluid. Various types of turbines can be employed, such as those driven by wind or falling water. The sources of power for these turbines consist of steam generated through nuclear fission and the burning of fossil fuels like coal, natural gas, or petroleum. Gas turbine power plants directly employ gases produced from burning natural gas or oil to drive the turbines. Combined cycle gas turbine plants utilize both steam and natural gas to operate their turbines.
They generate power by burning natural gas in a gas turbine and use residual heat to generate additional electricity from steam. These plants offer efficiencies of up to 60%.
Renewables. The steam generated by:
– Biomass
– The sun as the heat source: solar parabolic troughs and solar power towers concentrate sunlight to heat a heat transfer fluid, which is then used to produce steam.
– Geothermal power. Either steam under pressure emerges from the ground and drives a turbine or hot water evaporates a low boiling liquid to create vapor to drive a turbine.
– Other renewable sources: Water (hydroelectric) – Turbine blades are acted upon by flowing water, produced by hydroelectric dams or tidal forces. Wind – Most wind turbines generate electricity from naturally occurring wind.
Solar updraft towers utilize sunlight to heat the air inside the chimney, artificially creating wind and functioning as a type of solar thermal energy. Small electric generators commonly rely on reciprocating engines that burn diesel, biogas, or natural gas. Diesel engines are typically used for backup power generation, particularly at lower voltages. Larger power grids also employ Diesel generators, originally intended for emergency backup purposes at specific facilities like hospitals, to supply electricity to the grid during certain situations. Biogas is often combusted at its production site, such as a landfill or wastewater treatment plant, using a reciprocating engine or a microturbine, which is a small gas turbine. In Laughlin, Nevada, USA, there is a coal-fired power plant.
The plant owners ceased operations as they refused to invest in pollution control equipment to comply with regulations. Photovoltaic panels directly convert sunlight into electricity, unlike solar heat concentrators. Although solar electricity generation is more expensive than mechanically produced power due to the panel cost, sunlight is abundant and free. However, the price of low-efficiency silicon solar cells has decreased, and commercially available multijunction cells can now achieve nearly 30% conversion efficiency. Experimental systems have demonstrated efficiency levels exceeding 40%.
Previously, photovoltaics were mainly used in remote areas without access to a commercial power grid or as an additional source of electricity for homes and businesses. However, recent advancements in manufacturing efficiency and photovoltaic technology, along with environmental subsidies, have significantly increased panel usage. Panel installations are growing at a rate of 40% per year driven by increases in Germany, Japan, California, and New Jersey. Wind-powered turbines are commonly utilized alongside other methods of power generation while various other technologies have been researched and developed for power generation.
Solid-state power generation is commonly used in portable applications, where there are no moving parts. This field primarily relies on thermoelectric (TE) devices, although thermionic (TI) and thermophotovoltaic (TPV) systems have also been developed. It should be noted that TE devices operate at lower temperatures compared to TI and TPV systems.
Aside from TE devices, piezoelectric devices also play a role in power generation by converting mechanical strain into electricity. They are particularly useful for power harvesting. Another type of solid-state power generator is betavoltaics, which generates electricity through radioactive decay.
Moreover, fluid-based magnetohydrodynamic (MHD) power generation has been explored as a means of extracting electrical power from nuclear reactors and conventional fuel combustion systems.
Osmotic power is an additional option that can be used in places where salt and sweet water converge, such as deltas. Electrochemical electricity generation is also significant in the field of portable and mobile applications. Currently, most electrochemical power comes from closed electrochemical cells, commonly known as batteries [7]. These cells are often used more for storage than for generation. However, fuel cells, which are open electrochemical systems, have been extensively researched and developed in recent years. Fuel cells have the ability to extract power from natural fuels or synthesized fuels like electrolytic hydrogen. As a result, they can be considered either generation systems or storage systems depending on their intended purpose.
