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Renewable energy is energy that comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished.)
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Renewable energy is an alternative to fossil fuels and nuclear power, and was commonly called alternative energy in the 1970s and 1980s.
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In 2008, about 19% of global final energy consumption came from renewables, with 13% coming from traditional biomass, which is mainly used for heating, and 3.2% from hydroelectricity.
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New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.7% and are growing very rapidly.
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The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewables.
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| EMU solar panels |
by functoruser on Flickr |
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Solar Power
Solar energy is one the most resourceful sources of energy for the future. One of the reasons for this is that the total energy we get each year from the sun is around 35,000 times the total energy used by man. However, about 1/3 of this energy is either absorbed by the outer atmosphere or reflected back into space (a process called albedo).Right now, solar energy is being used on a smaller scale in furnaces for homes and to heat up swimming pools. On a larger scale use, solar energy could be used to run cars, power plants, and space ships.
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| Windmills |
by Monica's Dad on Flickr |
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Wind Power
Wind power is another alternative energy source that could be used without producing by-products that are harmful to nature. Like solar power, harnessing the wind is highly dependent upon weather and location. The average wind velocity of Earth is around 9 m/sec. And the power that could be produced when a wind mill is facing the wind of 10 mi/hr. is around 50 watts.
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| [IDAHO-G-0004] Salmon Power Plant |
by waterarchives on Flickr |
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Hydroelectric Power
This is the old hydroelectric plant on the Salmon River in Idaho. Hydroelectricity comes from the damming of rivers and utilizing the potential energy stored in the water. As the water stored behind a dam is released at high pressure, its kinetic energy is transferred onto turbine blades and used to generate electricity. This system has enormous costs up front, but has relatively low maintenance costs and provides power quite cheaply. In the United States approximately 180,000 MW of hydroelectric power potential is available, and about a third of that is currently being harnessed.
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| Geothermal Dome |
by rwhgould on Flickr |
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Geothermal Power
This is a Geothermal dome. Geothermal energy is an alternative energy source, although it is not resourceful enough to replace more than a minor amount of the future's energy needs. Geothermal energy is obtained from the internal heat of the planet and can be used to generate steam to run a steam turbine. This in turn generates electricity, which is a very useful form of energy.
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| Waves over San José |
by Ani Carrington on Flickr |
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Tidal Power
Similar to the more conventional hydroelectric dams, the tidal process utilizes the natural motion of the tides to fill reservoirs, which are then slowly discharged through electricity-producing turbines. The former USSR produced 300 MW in its Lumkara plant using this method.
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| Power Girl |
by levork on Flickr |
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Lets Save Energy
- turn off lights
- shut off computers
- turn off entertainment devices
- use natural light, heat, and cooling
- use Energy Star appliances
- use programmable digital thermastats
- replace old windows, doors, roofs,etc.
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