Renewable power has been a topic of debate for decades, and the discussion tends to come down to cost and environmental impact: Some point out that it is "greener" to harness and generate electricity from types of renewable power such as solar energy or wind power, while others point out that it is cheaper to drill for oil.
Definition
Renewable resources are those that are constantly replenished, such as wind and solar energy. In contrast, much of the electricity used in the world is derived from fossil fuels such as coal, oil and natural gas. These resources are available in limited quantities and take millions of years to replace.
History
Renewable resources, such as wind, water and solar power, have been the default energy sources for much of human history because they were widely available in most areas and did not require complex technology to use. According to Bill Kovarik of Radford University, interest in renewable power escalated during the Industrial Revolution with the concern that coal reserves would dwindle. Throughout the 20th century, interest in renewable power has waxed and waned, generally with the cost of fossil fuels.
Types
Renewable power is derived from one of several sources: wind, solar, hydroelectric, geothermal or biomass. Large propeller blades mounted on tall towers capture the strongest, least turbulent wind. As wind turns the propeller blades, they generate electricity. Solar power can be converted to electricity through photovoltaic cells or used directly to provide heat and light. Flowing water powers turbines that generate electricity, making hydroelectric energy. Geothermal power is derived from the heat below the surface of the Earth. In some areas, steam from hot springs is used to power generators. Finally, biomass fuels are made from agricultural products such as corn and from industrial byproducts such as lumber-mill scrap and paper-mill residue. Methane gas captured from landfills is used for heating, cooking and fuel for some vehicles.
Advantages
Capturing and using renewable power often makes less of an environmental impact than extracting fossil fuels, which must be drilled or mined from below the surface of the Earth. Geothermal power does require drilling, but on a much smaller scale than industrial oil rigs. Energy from renewable resources can also lower energy expenses over several years.
Disadvantages
Generating electricity from renewable sources often requires a large amount of money upfront. It is harder for renewable sources to produce the massive quantities of energy that fossil fuels are able to, according to Renewable Energy Today. Production of wind and solar energy, for example, can be limited by weather conditions.
Renewable Energy Certificates
When renewable power is not locally available, some businesses and individuals purchase renewable energy certificates to offset their fossil-fuel consumption. Renewable energy certificates are created for every megawatt hour of renewable power that is released onto the shared power grid, and they can be purchased separately from the physical electricity that is generated from renewable resources.
References
- National Renewable Energy Laboratory: Learning About Renewable Energy
- United States Environmental Protection Agency: Renewable Energy Certificates
- Radford University: The Summer Spirit
- Radford University: The Summer Spirit Graphical Timeline
- Renewable Energy Today: Advantages and Disadvantages of Renewable Energy
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