Where Do We Get Energy?
Most frequently, we get energy from burning fossil flues, but it can also come from nuclear and hydroelectric power. All three methods pose environmental problems. Solar and wind energy, however, are among more eco-friendly, renewable energy resources – that means we can’t use them up. Major sources of energy depletion are transportation, home heating, air conditioning, hot water, and inefficient appliances, motors and lighting.
1. Fossil Fuels
Fossil fuels are made when organic matter is compressed under the earth’s crust for millions of years. We extract this matter and burn it as energy at a rate much faster than it can rebuild (Thus, it’s non-renewable.) Over 75 percent of the world’s electricity comes from burning fossil fuels. In addition to the pollution caused by oil extraction and transportation, fossil fuels spew out pollutants like carbon dioxide, carbon monoxide, nitrogen oxide, hydrogen sulfide, and sulfur dioxide.
2. Nuclear Energy
Splitting (fission) or joining (fusion) two atomic nuclei creates nuclear energy. The heat from fission is controlled in a reactor to heat pressurized water that drives a generator to create electricity. Unfortunately, the process of splitting atoms creates highly radioactive products that are hazardous to living creatures. Scientists have not figured out how to get rid of this waste practically and safely, as most has a half-life ranging from decades to thousands of years. (that means only half of it will have broken down in decades or thousands of years).
3. Hydroelectric Energy
Hydroelectric energy is created by controlling the amount of water that flows out of a man-made dam and over a turbine. The farther the water falls, the more energy we get. Unfortunately, creating dams can devastate entire ecosystems; naturally flowing rivers fuel the lives of animals and fish populations. When a river is dammed, life depending on the river further downstream suffers tremendously. In addition, creatures like salmon that depend on free rivers get stuck at the dam and cannot spawn or perform other necessary functions. Hydroelectric energy also contributes to deforestation and erosion.
4. Solar Energy
The suns rays can be transformed into electricity and heating in several ways. One popular method employs the use of photovoltaics (PVS). PVs use cells that absorb light and convert it into electricity by emitting electrons. “Solar mats” can also be used to heat water in solar water heaters. The angle and location of the sun at all times of the year is calculated and a house is built to maximize heat gain in winter and heat loss, or evasion in summer. Solar energy is considered one of the cleanest and safest sources of energy. The American Solar Energy Society>
5. Wind Energy
We can get energy from the wind by setting up turbines that look like large fans. When the wind blows through them, it causes their blades to spin. The spinning turbines drive electricity generators. Individual homeowners can use small turbines for smaller energy needs, but greater energy requires larger and more numerous turbines. Though wind turbines have a tendency to kill some birds of prey, scientists are working on technology to minimize bird life loss. Wind Energy Association.
At Sustainable energy you can learn sustainable energy sources such as geothermal, fuel cells, and
by Hilary Stamper, Care2.com's product manager and director of promotions