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In 1941, an American named Palmer Puttnam built the world's first really big wind turbine on top of a mountain. The turbine had two blades. Each was 175 feet (53 m) from tip to tip and sat on top of a 109-foot (33-m) tower. It worked successfully until March 1945, when one of its massive blades flew off. (Wind Power, 2003)
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Types of Renewable Energy
What is renewable energy?
Renewable energies are energies that can always be replaced over time. Not like burning fossil fuels, renewable energies are always there and have no negative impact on the environment.
The five most common renewable energies:
Hydro Power
What is it?
It is electricity produced from moving water.
How does it work?
The electricity is generated by the power of the moving water. The water used for generating electricity is usually runs down from a dam into penstocks and then get to many turbine generators. When the water runs pass the turbines, the water gives the turbines a push and this then the turbine spins to generate electricity.
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| This kind of renewable energy is very environmental. While using hydro power, there are no waste products and hydro power doesn’t pollute the air or the water. |
Even though hydro power is very environmental, there is still a disadvantage to it. The machine such as the dam changes the fish’s natural habitats. This would result some decrease in the number of fish because those fish cannot adapt to the sudden change in their environment. |
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| Large-Scale Hydropower (Clean Air Primer) | Hoover Dam, located on the Nevada-Arizona border (How Stuff Works) |
Biomass
What is it?
It is electricity produced from burning organic material made from plants and animals.
How does it work?
Electricity is produced by burning wastes from plants and animals just like burning fossil fuels but it is renewable. When the biomass is burned, heat is released. This creates a form of power to produce electricity and steam. Another way of using biomass to produce energy is to convert that biomass into other forms of energy such as methane gas or transportation fuels.
Types of Biomass
The most common biomass is wood, (When you have a fireplace, the wood you burn is the biomass) following crops, manure and some garbage. Not all garbage can be counted is biomass. Some garbage such as plastic, glass and metal are not counted as biomass because they are made from non-renewable products.
Biofuel
Biofuel are transportation fuels such as ethanol and biodiesel. They are renewable fuel that doesn’t pollute the air like fossil fuels. Ethanol is an alcohol fuel made from sugar in grains. It replaces the gasoline used in cars which helps to produce less air pollution. Biodiesel is a fuel made from vegetable oil, fat or grease. It can be used in diesel engines and help to produce fewer pollutants.
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| Biomass is always available as trees and animals keep on producing wastes. So we have an endless supply of biomass. |
One disadvantage that burning biomass have is that it pollutes the air while burning just like burning fossil fuels, yet it does not pollute as much as the fossil fuels. It only releases carbon dioxide while it is burned which causes the greenhouse affect. |
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| Types of biomass that can be changed into energy sources (World of Energy) | Michigan Biomass Curriculum Project (MACD) |
Solar Power
What is it?
Electricity produced by the energy from the sun.
How does it work?
Solar thermal collects sunlight from the sun and changes it directly into electricity.
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| Sunlight always exists on earth and it reaches almost every where on earth. |
The sun doesn’t provide a constant amount of sunlight at the same location, so a large surface area is needed to collect energy at a useful rate. Also, weather, location, time of day and time of year affect the amount of sunlight reaching the earth. |
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| A solar power plant in the Mojave Desert, with panels reflecting light up to a central tower.(ABC News) | The Solar Grove (Kyocera) |
Wind Power
What is it?
Electricity is produced from air in motion.
How does it work?
Machines are built in a form similar to windmills to collect the wind energy. The blades on the machines spin faster when the wind blows stronger. The spinning blades are connected to a drive shaft that turns an electric generator to produce electricity. There are also wind farms where there is a collection of wind machines to produce electricity.
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| Wind energy is a clean energy. It produces no pollution, or any form of wastes. |
The numbers of wind machines have a negative impact on the population of wild birds. Also, it has a visual impact on landscapes. Many wind machines are built on flat landscapes because wind usually blows stronger there, but it ruins the natural image of nature. |
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| Wind Turbines (Li Biz Blog) | New Zealand's Tararua Wind Power project has 48 Danish-built Vestas turbines able to generate 32 megawatts, enough to supply power to 15,000 homes. (The Sydney Morning Herald) |
Geothermal
What is it?
Geothermal energy is heat from within the earth. Volcano, hot springs and fumaroles are examples of geothermal energies that made its way up to the earth’s surface.
How does it work?
Electricity is produced in geothermal power plants. The magma under the earth surface heat up the underground water above it and that water is called hydrothermal resource. A place where hydrothermal resources cover a large area is called geothermal reservoirs. Geothermal power plants are built near those geothermal reservoirs to produce electricity.
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| This form of energy has almost no negative impact on the environment or natural habitat. |
Geothermal power plants do not burn fossil fuels but it still releases carbon dioxide. Yet even though it produces carbon dioxide, it only produces 1% to 3% of the carbon dioxide produced in a fossil fuel plant. |
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| US Geothermal Power Expanding (WattHead) | Geothermal power, Iceland Geothermal activity, geysers, photo by Jill Fehrenbacher (Inhabitat) |
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