How Electricity Is Generated
There are many ways to generate electricity. Let’s discuss how electricity is produced. Hydro plants, windmills, thermal plants, and nuclear plants all utilize turbines to generate electricity. In each case, the turbine operates in the same manner to produce electricity, with the only difference being the type of energy that drives the turbine. For example wind turbines convert the kinetic energy of wind into mechanical energy, hydro plants convert the pressure of water into mechanical energy, and thermal plants use steam energy to do the same.
Electricity generation can be understood through the functioning of turbines. When energy strikes the blades of a turbine, they begin to rotate transforming that energy into mechanical energy. The blades of the turbine are connected to a shaft, which also starts to rotate.
This rotating shaft is connected to a generator, which contains an alternator motor with electromagnets. These electromagnets are created by winding copper wire around stacks of magnetic steel laminations, also known as field poles.
As the shaft rotates the rotor attached to the field poles moves close to the conductors in the stator which creates a magnetic field which in turn generates electricity. This electricity is measured in kilowatts (kW) with 1 megawatt (MW) equaling 1,000 kW. A turbine can generate more than 1.54 kW in a day depending on various factors.
The generated electricity is then sent through output grids which deliver it directly to substations and, eventually, to homes, offices, or industrial areas via transmission lines.
History
The history of power generation is extensive and complex, featuring numerous technological milestones and contributors. This narrative often begins with English scientist Stephen Gray’s demonstrations of electric conduction, which led to the invention of glass friction generators in 1740 in Leyden, Germany. This development inspired Benjamin Franklin’s experiments and prompted Alessandro Volta of Italy to invent the battery in 1800.
In 1820, Michael Faraday and Joseph Henry invented a primitive electric motor and, in 1831, demonstrated that movement near a magnet could produce electric current—this principle is fundamental to generators.
The invention of the first rudimentary dynamo is credited to French scientist Hippolyte Pixii in 1832. Antonio Pacinotti improved it in 1860, providing continuous direct current (DC) power. Varley devised the “self-exciting dynamo-electric generator.” The most significant advancement came in 1870 when Belgian inventor Zenobe Gramme created a dynamo that produced a steady DC source suitable for powering motors. This discovery ignited a new enthusiasm for using electricity for lighting and power.
By 1877, many cities were illuminated with arc lighting (though these lights were too bright for ordinary rooms). In 1877, Charles F. Brush from Ohio developed the most reliable dynamo design and began selling it. Thomas Edison invented a less powerful incandescent lamp in 1879 and established a central generating station on Pearl Street in Manhattan just a month before the inaugural issue of POWER magazine in September 1882.
The Birth of Wind Turbines
In 1888, inventor Charles Brush built a 60-foot wind turbine in his backyard that could generate electricity. This marked the beginning of wind turbine development. Over time, interest in wind-powered turbines spread worldwide particularly in the American Midwest where they powered irrigation pumps. In 1941, a 1.25-MW turbine named “Grandpa’s Knob” was connected to the grid in Castleton, Vermont this was the world’s first grid-connected wind turbine.
The oil crisis of the 1970s reignited interest in wind power boosting research and development. In the U.S., wind power received policy support when President Jimmy Carter signed the Public Utility Regulatory Policies Act in 1978, requiring companies to purchase a certain amount of electricity from renewable energy sources including wind.
By the 1980s, California began constructing the first utility-scale wind farms while Europe took the lead in offshore wind, with the first offshore wind farm installed in Denmark in 1991. According to Wind Europe, by the end of 2021, Europe had an installed wind capacity of 236 GW, significantly up from 12.6 GW over the previous five years.
In late 2016, the first offshore wind farm in the U.S. a project of five turbines with a capacity of 30 MW, became operational in the waters off Block Island, Rhode Island. However, by 2022, only one more offshore wind project—the Coastal Virginia Offshore Wind pilot project, with two turbines and a capacity of 12 MW—had been added to the U.S. grid. Onshore wind installations performed better, with over 139 GW of onshore wind capacity connected to the grid by mid-2022, according to American Clean Power.
Development of Solar Power
Compared to other commercially available renewable energy sources, solar power is still in its infancy, but its commercial use has roots dating back 200 years. In 1839, French scientist Edmond Becquerel came to know about the photovoltaic effect while experimenting with an electrolytic cell containing two metal electrodes and a conducting solution. Becquerel observed that exposure to light increased electricity generation.
Three decades later, English electrical engineer Willoughby Smith discovered the photoconductivity of selenium. By 1882, New York inventor Charles Fritts created the first solar cell, which featured a layer of selenium coated with gold, achieving an energy conversion rate of only 1–2%.
By the 1950s, silicon solar cells entered commercial production. Physicists at Bell Laboratories found silicon to be more efficient than selenium. The cells developed by Bell Labs were the first solar cells capable of generating sufficient energy to power everyday electrical equipment, according to the U.S. Department of Energy (DOE).
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