ENERGY

Energy is the capacity to do work. Potential and kinetic energy are considered types of energy. Kinetic energy is the energy of motion. Potential energy is the energy associated with forces that depend on the position or configuration of a body and the surroundings.

A renewable energy source is considered a permanent energy source, that can be replenished as it is used (such as solar, wind, tidal). A non-renewable energy source is considered to be a temporary source; one which is depleted as it is used such as coal, oil and natural gas.

ENERGY SOURCES

Characteristics of Energy Sources According to the second law of thermodynamics, whenever energy is used, some is always lost into the environment as a less useful form of energy. In order for energy sources to be useful, these must involve processes which move towards lower energy states and release energy at reasonable rates (neither too fast nor too slow).

They should be easily accessible. If possible, their use should be harmless to the environment. They should be cheap and plentiful.

Current and Potential Energy Source chemical energy electric power fossil fuels nuclear energy solar energy wind energy

geothermal energy biomass energy hydropower energy ocean energy tidal energy

Chemical Energy Chemical energy is released during a chemical reaction. Chemical energy can also be converted to electrical energy in electrochemical cells (batteries) and fuel cells.

Electric Power Most of the world are becoming increasingly electrified. Today, more than half of the electricity generated in the world comes from coal. For the foreseeable future, coal will continue to be the dominant fuel used for electric power production. The low cost and abundance of coal is one of the primary reasons why consumers in the world benefit from some of the lowest electricity rates of any free-market economy.

Fossil Fuels Fossil fuels – coal, oil and natural gas -- currently provide more than 40% of all the energy consumed in the world, nearly two- thirds of the electricity, and virtually all of the transportation fuels. Moreover, it is likely that the nation’s reliance on fossil fuels to power an expanding economy will actually increase over at least the next two decades even with aggressive development and deployment of new renewable and nuclear technologies.

Coal Coal is one of the true measures of the energy strength of the world. One quarter of the world’s coal reserves are found within the United States, and the energy content of the nation’s coal resources exceeds that of all the world’s known recoverable oil. Coal is also the workhorse of the nation’s electric power industry.

Petroleum is a thick, dark liquid composed mostly of compounds called hydrocarbons that contain carbon and hydrogen. Natural Gas, usually associated with petroleum deposits, consists mostly of methane, but it also contains significant amounts of ethane, propane and butane.

Nuclear Energy Nuclear Energy is produced either by splitting (fission) or combining (fusion) of atoms. Fission: Splitting a heavy nucleus into two nuclei with smaller mass numbers. Fusion: Combining two light nuclei to form a heavier, more stable nucleus.

In the last three decades, nuclear power has played a significant role in electricity generation. Currently nuclear power supplies more than 10% of the world’s total electricity. It produces little pollution and virtually no greenhouse gases. Well-designed, constructed and operated nuclear power plants have proven to be reliable, safe, economical and environmentally benign.

Solar Energy Developing technologies that take advantage of the clean abundant energy of the sun is important to reducing greenhouse gasses and helps stimulate the economy. Examples of solar technologies are Photovoltaic cells, concentrating solar power technologies and low temperature solar collectors.Photovoltaic cells concentrating solar power technologies low temperature solar collectors

Photovoltaic cells convert sunlight directly into electricity. Photovoltaic cells provide tiny amounts of power for watches, large amounts for the electric grid, and everything in between. Concentrating solar power technologies use reflective materials to concentrate the sun's heat energy, which ultimately drives a generator to produce electricity. These technologies include dish/engine systems and central power towers. Low-temperature solar collectors also absorb the sun's heat energy, but the heat is used directly for hot water or space heating for residential, commercial, and industrial facilities.

Wind Energy Wind energy uses the energy in the wind for practical purposes like generating electricity, charging batteries, pumping water, or grinding grain. Wind turbines convert the kinetic energy of the wind into other forms of energy. Large, modern wind turbines operate together in wind farms to produce electricity for utilities. Small turbines are used by homeowners and remote villages to help meet energy needs.

Geothermal Energy Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.

Biomass Energy The term "biomass" means any plant derived organic matter available on a renewable basis, including dedicated energy crops and trees, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, animal wastes, municipal wastes, and other waste materials.

Biomass offers world tremendous opportunity to use domestic and sustainable resources to provide its fuel, power, and chemical needs from plants and plant-derived materials. Some departments and offices include major programs for developing and improving technology for biomass power; for making bio-fuels such as ethanol and renewable diesel; and for making plastics and chemicals from renewable, bio-based materials.

Hydropower Energy Although hydropower (also called hydroelectric power) currently provides about one fifth of the world’s electricity supply, development of the world’s remaining technical potential could, by no means, cover the growth in future demand. However, carefully planned hydropower development can, and does, make a great contribution to improving electrical system reliability and stability throughout the world. Also, future development will play an important role in the improvement of living standards in the developing world, where the greatest hydropower potential still exists.

Ocean Energy Ocean Thermal Energy Conversion (OTEC) is a means of converting into useful energy the temperature difference between surface water of the oceans in tropical and sub- tropical areas, and water at a depth of approximately meters which comes from the polar regions.

Tidal Energy Tidal power is a potential source of energy. One disadvantage is that it is not a continuos source of energy since electricity can only be generated when the tides are coming in or going out, thus requiring energy storage.

Questions 1. What is the meaning of “renewable energy source”? A renewable energy source is considered a permanent energy source, that can be replenished as it is used.

2. Give examples for renewable energy sources and non-renewable energy sources. Renewable energy sources: solar,wind,tidal energy sources Non-renewable energy sources: coal, oil and natural gas

3. What are current and potential energy sources? Chemical energy, electic power, fossil fuels, nuclear energy, solar energy, wind energy, geothermal energy, biomass energy, hydropower energy, ocean energy, tidal energy

4. What are the characteristics of energy sources? According to the second law of thermodynamics, whenever energy is used, some is always lost into the environment as a less useful form of energy. In order for energy sources to be useful, these must involve processes which move towards lower energy states and release energy at reasonable rates (neither too fast nor too slow).

They should be easily accessible. If possible, their use should be harmless to the environment. They should be cheap and plentiful.

5. Give examples for fossil fuels. Natural gas, oil and coal

6. What is the meaning of “fission of a nucleus”? Fission: Splitting a heavy nucleus into two nuclei with smaller mass numbers

7. What is the meaning of “nuclear fusion”? Fusion: Combining two light nuclei to form a heavier, more stable nucleus

8. What do you think about the energy sources that are found in Turkey and are not used very much? Sodal energy, tidal energy, wind energy, geothermal energy

9. What can be made by using biomass energy? Biomass offers world tremendous opportunity to use domestic and sustainable resources to provide its fuel, power, and chemical needs from plants and plant-derived materials. Some departments and offices include major programs for developing and improving technology for biomass power; for making bio-fuels such as ethanol and renewable diesel; and for making plastics and chemicals from renewable, bio-based materials.

10. What is the meaning of “Ocean Thermal Energy Conversion”? Ocean Thermal Energy Conversion (OTEC) is a means of converting into useful energy from the temperature difference between surface water of the oceans in tropical and sub-tropical areas, and water at a depth of approximately meters which comes from the polar regions.

I think that my presentation was not bad. I was so excited. Because of that, I could not present it very well. Self Evaluation

Peer Evaluation One of my friends said that my presentation was lack of visual knowledge. One of my friends said that I must write the key words on the slides and talk about them.

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