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Unit of Learning Electricity and generation of electricity

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Unit of Learning Electricity and generation of electricity

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Unit of Learning Electric current and generation of electricity

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Electricity calculations Lesson plan (Autosaved)

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Quick Info

Born

16 March 1789
Erlangen, Bavaria (now Germany)

Died

6 July 1854
Munich, Bavaria, Germany

Summary

Georg Simon Ohm was a German mathematician best known for Ohm's Law on electrical resistance.

Biography

Georg Simon Ohm came from a Protestant family. His father, Johann Wolfgang Ohm, was a locksmith while his mother, Maria Elizabeth Beck, was the daughter of a tailor. Although his parents had not been formally educated, Ohm's father was a rather remarkable man who had educated himself to a high level and was able to give his sons an excellent education through his own teachings. Had Ohm's brothers and sisters all survived he would have been one of a large family but, as was common in those times, several of the children died in their childhood. Of the seven children born to Johann and Maria Ohm only three survived, Georg Simon, his brother Martin who went on to become a well-known mathematician, and his sister Elizabeth Barbara.

When they were children, Georg Simon and Martin were taught by their father who brought them to a high standard in mathematics, physics, chemistry and philosophy. This was in stark contrast to their school education. Georg Simon entered Erlangen Gymnasium at the age of eleven but there he received little in the way of scientific training. In fact this formal part of his schooling was uninspired stressing learning by rote and interpreting texts. This contrasted strongly with the inspired instruction that both Georg Simon and Martin received from their father who brought them to a level in mathematics which led the professor at the University of Erlangen, Karl Christian von Langsdorf, to compare them to the Bernoulli family. It is worth stressing again the remarkable achievement of Johann Wolfgang Ohm, an entirely self-taught man, to have been able to give his sons such a fine mathematical and scientific education.

In 1805 Ohm entered the University of Erlangen but he became rather carried away with student life. Rather than concentrate on his studies he spent much time dancing, ice skating and playing billiards. Ohm's father, angry that his son was wasting the educational opportunity that he himself had never been fortunate enough to experience, demanded that Ohm leave the university after three semesters. Ohm went (or more accurately, was sent) to Switzerland where, in September 1806, he took up a post as a mathematics teacher in a school in Gottstadt bei Nydau.

Karl Christian von Langsdorf left the University of Erlangen in early 1809 to take up a post in the University of Heidelberg and Ohm would have liked to have gone with him to Heidelberg to restart his mathematical studies. Langsdorf, however, advised Ohm to continue with his studies of mathematics on his own, advising Ohm to read the works of Euler, Laplace and Lacroix. Rather reluctantly Ohm took his advice but he left his teaching post in Gottstadt bei Nydau in March 1809 to become a private tutor in Neuchâtel. For two years he carried out his duties as a tutor while he followed Langsdorf's advice and continued his private study of mathematics. Then in April 1811 he returned to the University of Erlangen.

His private studies had stood him in good stead for he received a doctorate from Erlangen on 25 October 1811 and immediately joined the staff as a mathematics lecturer. After three semesters Ohm gave up his university post. He could not see how he could attain a better status at Erlangen as prospects there were poor while he essentially lived in poverty in the lecturing post. The Bavarian government offered him a post as a teacher of mathematics and physics at a poor quality school in Bamberg and he took up the post there in January 1813.

This was not the successful career envisaged by Ohm and he decided that he would have to show that he was worth much more than a teacher in a poor school. He worked on writing an elementary book on the teaching of geometry while remaining desperately unhappy in his job. After Ohm had endured the school for three years it was closed down in February 1816. The Bavarian government then sent him to an overcrowded school in Bamberg to help out with the mathematics teaching.

On 11 September 1817 Ohm received an offer of the post of teacher of mathematics and physics at the Jesuit Gymnasium of Cologne. This was a better school than any that Ohm had taught in previously and it had a well equipped physics laboratory. As he had done for so much of his life, Ohm continued his private studies reading the texts of the leading French mathematicians Lagrange, Legendre, Laplace, Biot and Poisson. He moved on to reading the works of Fourier and Fresnel and he began his own experimental work in the school physics laboratory after he had learnt of Oersted's discovery of electromagnetism in 1820. At first his experiments were conducted for his own educational benefit as were the private studies he made of the works of the leading mathematicians.

The Jesuit Gymnasium of Cologne failed to continue to keep up the high standards that it had when Ohm began to work there so, by 1825, he decided that he would try again to attain the job he really wanted, namely a post in a university. Realising that the way into such a post would have to be through research publications, he changed his attitude towards the experimental work he was undertaking and began to systematically work towards the publication of his results :-

Overburdened with students, finding little appreciation for his conscientious efforts, and realising that he would never marry, he turned to science both to prove himself to the world and to have something solid on which to base his petition for a position in a more stimulating environment.
In fact he had already convinced himself of the truth of what we call today "Ohm's law" namely the relationship that the current through most materials is directly proportional to the potential difference applied across the material. The result was not contained in Ohm's firsts paper published in 1825, however, for this paper examines the decrease in the electromagnetic force produced by a wire as the length of the wire increased. The paper deduced mathematical relationships based purely on the experimental evidence that Ohm had tabulated.

In two important papers in 1826, Ohm gave a mathematical description of conduction in circuits modelled on Fourier's study of heat conduction. These papers continue Ohm's deduction of results from experimental evidence and, particularly in the second, he was able to propose laws which went a long way to explaining results of others working on galvanic electricity. The second paper certainly is the first step in a comprehensive theory which Ohm was able to give in his famous book published in the following year.

What is now known as Ohm's law appears in this famous book Die galvanische Kette, mathematisch bearbeitet (1827) in which he gave his complete theory of electricity. The book begins with the mathematical background necessary for an understanding of the rest of the work. We should remark here that such a mathematical background was necessary for even the leading German physicists to understand the work, for the emphasis at this time was on a non-mathematical approach to physics. We should also remark that, despite Ohm's attempts in this introduction, he was not really successful in convincing the older German physicists that the mathematical approach was the right one. To some extent, as Caneva explains in , this was Ohm's own fault:-
... in neither the introduction nor the body of the work, which contained the more rigorous development of the theory, did Ohm bring decisively home either the underlying unity of the whole or the connections between fundamental assumptions and major deductions. For example, although his theory was conceived as a strict deductive system based on three fundamental laws, he nowhere indicated precisely which of their several mathematical and verbal expressions he wished to be taken as the canonical form.
It is interesting that Ohm's presents his theory as one of contiguous action, a theory which opposed the concept of action at a distance. Ohm believed that the communication of electricity occurred between "contiguous particles" which is the term Ohm himself uses. The paper is concerned with this idea, and in particular with illustrating the differences in scientific approach between Ohm and that of Fourier and Navier. A detailed study of the conceptual framework used by Ohm in formulating Ohm's law is given in .

As we described above, Ohm was at the Jesuit Gymnasium of Cologne when he began his important publications in 1825. He was given a year off work in which to concentrate on his research beginning in August 1826 and although he only received the less than generous offer of half pay, he was able to spend the year in Berlin working on his publications. Ohm had believed that his publications would lead to his receiving an offer of a university post before having to return to Cologne but by the time he was due to begin teaching again in September 1827 he was still without such an offer.

Although Ohm's work strongly influenced theory, it was received with little enthusiasm. Ohm's feeling were hurt, he decided to remain in Berlin and, in March 1828, he formally resigned his position at Cologne. He took some temporary work teaching mathematics in schools in Berlin.

He accepted a position at Nüremberg in 1833 and although this gave him the title of professor, it was still not the university post for which he had strived all his life. His work was eventually recognised by the Royal Society with its award of the Copley Medal in Ⓣ( The galvanic chain, processed mathematically ) 1841. He became a foreign member of the Royal Society in 1842. Other academies such as those in Berlin and Turin elected him a corresponding member, and in 1845 he became a full member of the Bavarian Academy.

This belated recognition was welcome but there remains the question of why someone who today is a household name for his important contribution struggled for so long to gain acknowledgement. This may have no simple explanation but rather be the result of a number of different contributary factors. One factor may have been the inwardness of Ohm's character while another was certainly his mathematical approach to topics which at that time were studied in his country a non-mathematical way. There was undoubtedly also personal disputes with the men in power which did Ohm no good at all. He certainly did not find favour with Johannes Schultz who was an influential figure in the ministry of education in Berlin, and with Georg Friedrich Pohl, a professor of physics in that city.

Electricity was not the only topic on which Ohm undertook research, and not the only topic in which he ended up in controversy. In 1843 he stated the fundamental principle of physiological acoustics, concerned with the way in which one hears combination tones. However the assumptions which he made in his mathematical derivation were not totally justified and this resulted in a bitter dispute with the physicist August Seebeck. He succeeded in discrediting Ohm's hypothesis and Ohm had to acknowledge his error. See for details of the dispute between Ohm and Seebeck.

In 1849 Ohm took up a post in Munich as curator of the Bavarian Academy's physical cabinet and began to lecture at the University of Munich. Only in 1852, two years before his death, did Ohm achieve his lifelong ambition of being appointed to the chair of physics at the University of Munich.

Written by J J O'Connor and E F Robertson
Last Update January 2000

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Born 16 March 1789 Erlangen, Bavaria (now Germany) Died 6 July 1854 Munich, Bavaria, Germany Summary Georg Simon Ohm was a German mathematician best known for Ohm's Law on electrical resistance. Georg Simon Ohm came from a Protestant family. His father, Johann Wolfgang Ohm, was a locksmith while his mother, Maria Elizabeth Beck, was the daughter of a tailor.

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An electric generator is a device that converts a form of energy into electricity. There are many different types of electricity generators. Most electricity generation is from generators that are based on scientist Michael Faraday's discovery in 1831. He found that moving a magnet inside a coil of wire makes (induces) an electric current flow through the wire. He made the first electricity generator, called a Faraday disk, which operates on the relationship between magnetism and electricity and led to the design of the electromagnetic generators we use today.

Electromagnetic generators use an electromagnet-a magnet produced by electricity-not a traditional magnet. A basic electromagnetic generator has a series of insulated wire coils that form a stationary cylinder-called a stator-surrounding an electromagnetic shaft-called a rotor. Turning the rotor makes an electric current flow in each section of the wire coil, and each section becomes a separate electric conductor. The currents in the individual sections combine to form one large current. This current is the electricity that moves from generators through power lines to consumers. Electromagnetic generators driven by kinetic (mechanical) prime movers account for nearly all U.S. electricity generation.

Turbine driven generators

Most U.S. and world electricity generation is from electric power plants that use a to drive electricity generators. In a turbine generator, a moving fluid-water, steam, combustion gases, or air-pushes a series of blades mounted on a rotor shaft. The force of the fluid on the blades spins (rotates) the rotor shaft of a generator. The generator, in turn, converts the mechanical (kinetic) energy of the rotor to electrical energy. Different types of turbines include steam turbines, combustion (gas) turbines, hydroelectric turbines, and wind turbines.

Steam turbines are used to generate most of the world's electricity, and they accounted for about 42% of U.S. electricity generation in 2022. Most steam turbines have a boiler where fuel is burned to produce hot water and steam in a heat exchanger, and the steam powers a turbine that drives a generator. Nuclear power reactors use nuclear fuel rods to produce steam. Solar thermal power plants and most geothermal power plants use steam turbines. Most of the largest U.S. electric power plants use steam turbines.

Combustion gas turbines, which are similar to jet engines, burn gaseous or liquid fuels to produce hot gases to turn the blades in the turbine.

Steam and combustion turbines can be operated as stand-alone generators in a single-cycle or combined in a sequential, combined-cycle. Combined-cycle systems use combustion gases from one turbine to generate more electricity in another turbine. Most combined-cycle systems have separate generators for each turbine. In single-shaft combined cycle systems, both turbines may drive a single generator. In 2022, combined-cycle power plants supplied about 34% of U.S. net electricity generation.

Combined-heat-and-power plants (CHP) and cogenerators, use the heat that is not directly converted to electricity in a steam turbine, combustion turbine, or an internal combustion engine generator for industrial process heat or for space and water heating. Most of the largest CHP plants in the United States are at industrial facilities such as pulp and paper mills, but they are also used at many colleges, universities, and government facilities. CHP and combined-cycle power plants are among the most efficient ways to convert a combustible fuel into useful energy.

Hydroelectric turbines use the force of moving water to spin turbine blades to power a generator. Most hydroelectric power plants use water stored in a reservoir or diverted from a river or stream. These conventional hydroelectric power plants accounted for about 6% of U.S. electricity generation in 2022. Pumped-storage hydropower plants use the same types of hydro turbines that conventional hydropower plants use, but they are considered energy storage systems. Other types of hydroelectric turbines called hydrokinetic turbines are used in tidal power and wave power systems.

Wind turbines use the power in wind to move the blades of a rotor to power a generator. There are two general types of wind turbines: horizontal axis (the most common) and vertical-axis turbines. Wind turbines were the source of about 10% of U.S. electricity generation in 2022.

Ocean thermal energy conversion (OTEC) systems use a temperature difference between ocean water at different depths to power a turbine to produce electricity.

Other types of generators

Many different types of electricity generators do not use turbines to generate electricity. The most common in use today are solar photovoltaic (PV) systems and internal-combustion engines.

Solar photovoltaic cells convert sunlight directly into electricity. These cells may be used to power devices as small as wrist watches. They are also connected together in modules (or panels), which can be connected together in multi-module arrays to power individual homes or form large power plants. Photovoltaic power plants are now one of the fastest growing sources of electricity generation around the world. In the United States, PV power plants were the source of about 3% of total utility-scale electricity generation in 2022.

Internal=combustion engines, such as diesel engines, are used all around the world for electricity generation, including in many remote villages in Alaska. They are also widely used for mobile power supply at construction sites and for emergency or backup power supply for buildings and power plants. Diesel-engine generators can use a variety of fuels, including petroleum diesel, biomass-based liquid fuels and biogas, natural gas, and propane. Small internal-combustion-engine generators fueled with gasoline, natural gas, or propane are commonly used by construction crews and tradespeople and for emergency power supply for homes.

Other types of electricity generators include fuel cells, Stirling engines (used in solar thermal parabolic-dish generators), and thermoelectric generators.

Energy storage systems for electricity generation include hydro-pumped storage, compressed-air storage, electrochemical batters, and flywheels. These energy storage systems use electricity to charge a storage facility or device, and the amount of electricity they can supply is less than the amount they use for charging. Therefore, the net electricity generation from storage systems is counted as negative in EIA reports (Electric Power Monthly and Electric Power Annual) to avoid double counting electricity use for charging the storage system.

Data source: U.S. Energy Information Administration (EIA), Form EIA-923 Power Plant Operations Report, final data for 2022
Note: Sum of subtotals may not equal totals because of independent rounding of individual data series.
¹ Includes generators at power plants with at least one megawatt electricity generation capacity
² Natural gas accounted for 99% of energy sources in combined-cycle power plants and for 95% of energy sources in single-cycle combustion gas turbines.
³ Other sources include internal combustion engines, fuel cells, and binary-cycle turbines.
⁴ Storage systems include hydro-pumped storage, electrochemical batteries, compressed-air storage, and flywheels. The percentage share of total utility-scale electricity net generation from energy storage systems for electricity generation is shown as positive in the table above. However, generation from storage systems is published as negative net generation in EIA reports (Electric Power Monthly and Electric Power Annual) to avoid double counting of energy storage charging sources.
Last updated: October 27, 2023, with data available at the time of update.

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How electricity is generated - U.S. Energy Information Administration (EIA)

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How electricity is generated by various types of electricity generation technologies and power plants.

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The amount of electrical energy changed to other forms of energy in one second

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Challenge; overcoming use of fossil fuels to generate electricity

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Challenge; overcoming use of fossil fuels to generate electricity

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Can governments give up using fossil fuels to save the climate? | Inside Story

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Electromagnet invented 1825 by William Sturgeon
In 1825, Lancastrian electrician, William Sturgeon, revealed his invention of the electromagnet. This enabled electrical energy to be used in the design of controllable machinery. Sturgeon was an amazing man
He had a difficult start to life, his mother died when he was quite young and his father sent him away to become apprenticed to a boot maker. Life didn't become much easier when he joined the army.

He was sent to the Royal Artillery base in Woolwich and married a widow who kept a local shoe menders. But sadness followed him and all three of his children and his wife died. He immersed himself in self education, teaching himself mathematics and a range of languages including Greek. He also studied science and philosophy and honed his practical mechanical skills.

The army sent him to Newfoundland and whilst there observed many thunderstorms which inspired a fascination with electricity.

Although he left the army, William Sturgeon had made connections with many people who thought like him, the Greenwich Royal Observatory was only a stones throw away and the Royal Military Academy trained the Royal Artillery and the Royal Engineers.

Electromagnetism, discovered by Hans Christian Oersted, was already well known about and William Sturgeon became very interested in it's effects.

In 1824 he was appointed lecturer in Science and Philosophy at the East India Royal Military College and lecturer in science at the Royal Military College and by 1825 was able to show his first working electromagnet but he didn't stop there. In 1832 he built an electric motor and invented the commutator, an integral part of most modern electric motors. He lectured at the Adelaide gallery for practical science, patronized by people such as Thomas Telford. He also invented the first suspended coil galvanometer, a device for measuring current. As a result of his work, the American inventor, Joseph Henry, produced a far more powerful magnet which led to the development of an electronic communication system, the telegraph.
William Sturgeon died in 1850 in Prestwich Lancashire.

The mixing of scientific talents at clubs and galleries such as the Adelaide, helped to promote a general interest in sciences and Sturgeon was keen that science and entertainment should go hand in hand to bring it to the general public

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Electromagnet Invented 1825 by William Sturgeon

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In 1825, Lancastrian electrician, William Sturgeon, revealed his invention of the electromagnet. This enabled electrical energy to be used in the design of controllable machinery. Sturgeon was an amazing man He had a difficult start to life, his mother died when he was quite young and his father sent him away to become apprenticed to a boot maker.

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By Elizabeth Morse

Thursday, February 21, 2013

The wind, the sun, and Earth are sources of renewable energy. These energy sources naturally renew, or replenish themselves.

Wind, sunlight, and the planet have energy that transforms in ways we can see and feel. We can see and feel evidence of the transfer of energy from the sun to Earth in the sunlight shining on the ground and the warmth we feel when sunlight shines on our skin. We can see and feel evidence of the transfer of energy in wind's ability to pull kites higher into the sky and shake the leaves on trees. We can see and feel evidence of the transfer of energy in the geothermal energy of steam vents and geyser s.

People have created different ways to capture the energy from these renewable sources.

Active solar energy uses special technology to capture the sun's rays. The two main types of equipment are photovoltaic cells (also called PV cells or solar cells) and mirrors that focus sunlight in a specific spot. These active solar technologies use sunlight to generate electricity, which we use to power lights, heating systems, computers, and televisions.

Passive solar energy does not use any equipment. Instead, it gets energy from the way sunlight naturally changes throughout the day. For example, people can build houses so their windows face the path of the sun. This means the house will get more heat from the sun. It will take less energy from other sources to heat the house.

Other examples of passive solar technology are green roofs, cool roofs, and radiant barriers. Green roofs are completely covered with plants. Plants can get rid of pollutants in rainwater and air. They help make the local environment cleaner.

Cool roofs are painted white to better reflect sunlight. Radiant barriers are made of a reflective covering, such as aluminum. They both reflect the sun's heat instead of absorbing it. All these types of roofs help lower the amount of energy needed to cool the building.

There are many advantages to using solar energy. PV cells last for a long time, about 20 years.

However, there are reasons why solar power cannot be used as the only power source in a community. It can be expensive to install PV cells or build a building using passive solar technology.

Sunshine can also be hard to predict. It can be blocked by clouds, and the sun doesn't shine at night. Different parts of Earth receive different amounts of sunlight based on location, the time of year, and the time of day.

People have been harnessing the wind's energy for a long, long time. Five-thousand years ago, ancient Egyptians made boats powered by the wind. In 200 B.C.E., people used windmills to grind grain in the Middle East and pump water in China.

Today, we capture the wind's energy with wind turbines. A turbine is similar to a windmill; it has a very tall tower with two or three propeller-like blades at the top. These blades are turned by the wind. The blades turn a generator (located inside the tower), which creates electricity.

Groups of wind turbines are known as wind farms. Wind farms can be found near farmland, in narrow mountain passes, and even in the ocean, where there are steadier and stronger winds. Wind turbines anchored in the ocean are called " offshore wind farms."

Wind farms create electricity for nearby homes, schools, and other buildings.

Wind energy can be very efficient. In places like the Midwest in the United States and along coasts, steady winds can provide cheap, reliable electricity.

Another great advantage of wind power is that it is a "clean" form of energy. Wind turbines do not burn fuel or emit any pollutants into the air.

Wind is not always a steady source of energy, however. Wind speed changes constantly, depending on the time of day, weather, and geographic location. Currently, it cannot be used to provide electricity for all our power needs.

Wind turbines can also be dangerous for bats and birds. These animals cannot always judge how fast the blades are moving and crash into them.

Deep beneath the surface is Earth's core. The center of Earth is extremely hot-thought to be over 6,000 °C (about 10,800 °F). The heat is constantly moving toward the surface.

We can see some of Earth's heat when it bubbles to the surface. Geothermal energy can melt underground rocks into magma and cause the magma to bubble to the surface as lava. Geothermal energy can also heat underground sources of water and force it to spew out from the surface. This stream of water is called a geyser.

However, most of Earth's heat stays underground and makes its way out very, very slowly.

We can access underground geothermal heat in different ways. One way of using geothermal energy is with "geothermal heat pumps." A pipe of water loops between a building and holes dug deep underground. The water is warmed by the geothermal energy underground and brings the warmth aboveground to the building. Geothermal heat pumps can be used to heat houses, sidewalks, and even parking lots.

Another way to use geothermal energy is with steam. In some areas of the world, there is underground steam that naturally rises to the surface. The steam can be piped straight to a power plant. However, in other parts of the world, the ground is dry. Water must be injected underground to create steam. When the steam comes to the surface, it is used to turn a generator and create electricity.

In Iceland, there are large reservoirs of underground water. Almost 90% of people in Iceland use geothermal as an energy source to heat their homes and businesses.

An advantage of geothermal energy is that it is clean. It does not require any fuel or emit any harmful pollutants into the air.

Geothermal energy is only avaiable in certain parts of the world. Another disadvantage of using geothermal energy is that in areas of the world where there is only dry heat underground, large quantities of freshwater are used to make steam. There may not be a lot of freshwater. People need water for drinking, cooking, and bathing.

Biomass is any material that comes from plants or microorganisms that were recently living. Plants create energy from the sun through photosynthesis. This energy is stored in the plants even after they die.

Trees, branches, scraps of bark, and recycled paper are common sources of biomass energy. Manure, garbage, and crops, such as corn, soy, and sugar cane, can also be used as biomass feedstock s.

We get energy from biomass by burning it. Wood chips, manure, and garbage are dried out and compressed into squares called "briquettes." These briquettes are so dry that they do not absorb water. They can be stored and burned to create heat or generate electricity.

Biomass can also be converted into biofuel. Biofuels are mixed with regular gasoline and can be used to power cars and trucks. Biofuels release less harmful pollutants than pure gasoline.

A major advantage of biomass is that it can be stored and then used when it is needed.

Growing crops for biofuels, however, requires large amounts of land and pesticides. Land could be used for food instead of biofuels. Some pesticides could pollute the air and water.

Biomass energy can also be a non-renewable energy source. Biomass energy relies on biomass feedstocks-plants that are processed and burned to create electricity. Biomass feedstocks can include crops, such as corn or soy, as well as wood. If people do not replant biomass feedstocks as fast as they use them, biomass energy becomes a non-renewable energy source.

Hydroelectric energy is made by flowing water. Most hydroelectric power plants are located on large dams, which control the flow of a river.

Dams block the river and create an artificial lake, or reservoir. A controlled amount of water is forced through tunnels in the dam. As water flows through the tunnels, it turns huge turbines and generates electricity.

Hydroelectric energy is fairly inexpensive to harness. Dams do not need to be complex, and the resources to build them are not difficult to obtain. Rivers flow all over the world, so the energy source is available to millions of people.

Hydroelectric energy is also fairly reliable. Engineers control the flow of water through the dam, so the flow does not depend on the weather (the way solar and wind energies do).

However, hydroelectric power plants are damaging to the environment. When a river is dammed, it creates a large lake behind the dam. This lake (sometimes called a reservoir) drowns the original river habitat deep underwater. Sometimes, people build dams that can drown entire towns underwater. The people who live in the town or village must move to a new area.

Hydroelectric power plants don't work for a very long time: Some can only supply power for 20 or 30 years. Silt, or dirt from a riverbed, builds up behind the dam and slows the flow of water.
Other Renewable Energy Sources
Scientists and engineers are constantly working to harness other renewable energy sources. Three of the most promising are tidal energy, wave energy, and algal (or algae) fuel.

Tidal energy harnesses the power of ocean tide s to generate electricity. Some tidal energy projects use the moving tides to turn the blades of a turbine. Other projects use small dams to continually fill reservoirs at high tide and slowly release the water (and turn turbines) at low tide.

Wave energy harnesses waves from the ocean, lakes, or rivers. Some wave energy projects use the same equipment that tidal energy projects do-dams and standing turbines. Other wave energy projects float directly on waves. The water's constant movement over and through these floating pieces of equipment turns turbines and creates electricity.

Algal fuel is a type of biomass energy that uses the unique chemicals in seaweed to create a clean and renewable biofuel. Algal fuel does not need the acres of cropland that other biofuel feedstocks do.

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By Elizabeth Morse Thursday, February 21, 2013 The wind, the sun, and Earth are sources of renewable energy. These energy sources naturally renew, or replenish themselves. Wind, sunlight, and the planet have energy that transforms in ways we can see and feel.

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mind map issues that arise from generation of electricity