Alternative energy is an umbrella term with many definitions. Most alternative energy research is targeted to provide electricity, heat or combustible fuel without the negative environmental impacts especially associated with fossil fuels.
Alternative energy technology is everywhere, but recognizing it can be challenging. Understanding the language of alternative energy provides a foundation for understanding and communication. As new technology gains market share, today's alternatives will become mainstream.
An Introduction to Alternative Energy Sources
- Wind power has been used for thousands of years. Ancient Egyptians are thought to be the first to harness wind to push sail barges. More recently, wind was used in the American West to pump water. Blades similar to airplane wings turn turbines which produce anywhere from a few watts to 5 Megawatts and more.
- Solar power energy harnesses sunlight to create heat or electricity. A greenhouse's extended growing season is a simple example of gathering sunlight to heat an area. Solar panels can be mounted on a roof or in an open area to heat water or convert sunlight into electricity.
- Geothermal energy converts heat within the Earth to usable energy. Early systems used hot water or steam which issued from the Earth. More recently, holes have been drilled into the crust so water can be pumped into the Earth and converted to steam. This steam can be used to create electricity.
- Hydro-electric projects use water and an elevation change to produce electricity. Hoover Dam is an engineering feat that produces electricity for 1.3 million people in the desert Southwest. Once a dam is built and the reservoir forms, water falls through turbines to produce electricity.
- Fuel cells are like rechargeable batteries that use a chemical reaction to produce heat, electricity and usually water as a by-product. FuelCell Energy publishes a description of their new technology which sites reduced emissions (no combustion by-products) and reliability as benefits over electricity generated by fossil fuel combustion.
- Biofuels are created from biomass. Biodiesel, renewable diesel, waste vegetable oil, corn ethanol and biogas are some examples of biofuels available today.
Benefits and Problems with Alternative Renewable Energy
Alternative energy is often described as green, meaning it does not harm the environment. Developed technologies often fulfill this description, providing energy with reduced pollution or greenhouse gasses (GHGs).
Problems arise when assessing these technologies through their life spans. For instance, biofuels have many detractors. While replacing petroleum fuels with biofuels in basic analysis reduces GHGs, emissions from manufacture, processing and distribution of the biofuel need consideration.
According to Koh and Ghazoul's article "Biofuels, biodiversity, and people: Understanding the conflicts and finding opportunities", published in volume 141 of Biological Conservation, 15 years of studies conclude there is a net reduction in GHGs when biofuels displace diesel or gasoline. The complexity of this issue means claims of GHG and other pollutant reduction need to be closely examined.
While strides have been made in alternative energy technologies and many of these can help reduce pollution, evaluations must be complete with regard to benefits. Scientists agree, however, that most alternative energy technologies have a place in the world energy portfolio.
Justin Novak - I graduated from Michigan Technological University in December of 2007 with a Bachelors of Science in Mechanical Engineering. My ...
