There are many reasons the world is looking for alternative energy sources in an effort to reduce pollutants and greenhouse gases. Alternative or renewable energy sources show significant promise in helping to reduce the number of toxins that are by-products of energy use and help preserve many of the natural resources that we currently use as sources of energy.
To understand how alternative energy use can help preserve the delicate ecological balance of the planet and help us conserve the non-renewable energy sources like fossil fuels, it is important to know what type of alternative energy is out there. Let's take a look at some of the most common sources available.
Wind energy harnesses the power of the wind to propel the blades of wind turbines. The rotation of turbine blades is converted into electrical current by means of an electrical generator. In the older windmills, wind energy was used to turn mechanical machinery to do physical work, like crushing grain or pumping water. Wind towers are usually built together on wind farms.
Now, electrical currents are harnessed by large-scale wind farms that are used by national electrical grids as well as small individual turbines used for providing electricity to isolated locations or individual homes. In 2005, worldwide capacity of wind-powered generators was 58,982 megawatts, their production making up less than 1 percent of worldwide electricity use.
The Pros of Wind Power
- Wind power produces no pollution that can contaminate the environment. Since no chemical processes take place, as in the burning of fossil fuels, there are no harmful by-products left over.
- Since wind generation is a renewable source of energy, we will never run out of it.
- Farming and grazing can still take place on land occupied by wind turbines, which can help in the production of biofuels.
- Wind farms can be built off-shore.
The Cons of Wind Power
- Wind power is intermittent. Consistent wind is needed for continuous power generation. If wind speed decreases, the turbine lingers and less electricity is generated.
- Large wind farms can have a negative effect on the scenery.
Solar energy is used commonly for heating, cooking, the production of electricity and even in the desalination of seawater. Solar power works by trapping the sun's rays into solar cells where this sunlight is then converted into electricity. Additionally, solar power uses sunlight that hits solar thermal panels to convert sunlight to heat water or air. Other methods include using sunlight that hits parabolic mirrors to heat water (producing steam) or simply opening a room's blinds or window shades to allow entering sunlight to passively heat a room.
The Pros of Solar Power
- Solar power is a renewable resource. As long as the Sun exists, its energy will reach Earth.
- Solar power generation releases no water or air pollution because there is no chemical reaction from the combustion of fuels.
- Solar energy can be used very efficiently for practical uses such as heating and lighting.
- The benefits of solar power are seen frequently to heat pools, spas, and water tanks all over.
The Cons of Solar Power
- Solar power does not produce energy if the sun is not shining. Nighttime and cloudy days seriously limit the amount of energy produced.
- Solar power stations can be very expensive to build.
Geothermal literally means "earth heat." Geothermal energy harnesses the heat energy present underneath the earth. Hot rocks under the ground heat water to produce steam. When holes are drilled in the region, the steam that shoots up is purified and is used to drive turbines, which power electric generators.
The Pros of Geothermal Energy
- If done correctly, geothermal energy produces no harmful by-products.
- Once a geothermal plant is built, it is generally self-sufficient energy wise.
- Geothermal power plants are usually small and have little effect on the natural landscape.
The Cons of Geothermal Energy
- If done incorrectly, geothermal energy can produce pollutants.
- Improper drilling into the earth can release hazardous minerals and gases.
- Geothermal sites are prone to running out of steam.
Hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. Another variation is to make use of water's kinetic energy or undammed sources such as tidal power. Hydropower works by harnessing the gravitational descent of a river that is compressed from a long run to a single location with a dam or a flume. This creates a location where concentrated pressure and flow of water can be used to turn turbines or water wheels to drive an electric generator. Electric generators powered by hydropower can be run backward as a motor to pump water back up for later use.
The Pros of Hydroelectric Energy
- Water can be accumulated above the dam and released to coincide with peaks in demand. So unlike other types of power stations, hydroelectric power stations can promptly increase to full capacity.
- Electricity can be generated constantly because there are no outside forces, unlike other forms of alternative energy, which affect the availability of water.
- Hydroelectric power produces no waste or pollution since there is no chemical reaction to produce power.
- Water used for hydropower can be reused.
The Cons of Hydroelectric Energy
- Dams can be very expensive to build.
- There needs to be a sufficient and powerful enough supply of water in the area to produce energy.