"Energy is the capacity to do work or make something happen." (Walker, 2007, 4) Without energy we would not have life on Earth. It is used to cook food, heat buildings and help both humans and plants survive. Every machine including cars, computers, televisions and the factories that produce them run on energy.
Anything that has energy, people can use as an energy source. There are two types of energy sources: non renewable and renewable. Non renewable sources cannot be replaced once they have been used and will eventually run out. Fossil fuels such as coal, oil and natural gas are examples of non renewable resources. Renewable resources are continually replaced by people and nature. They are also used to produce alternative energy sources, such as solar, wind and hydropower.
Oil, coal and natural gas are limited and scientists believe that there is about one hundred years of oil and natural gas left and about two hundred fifty years of coal left. Due to a consistent increase in population, the demand for energy continues to grow. As we begin to run out of fossil fuels, they also become more expensive to use. Since most of the technology we use everyday such as vehicles, furnaces, and power plants are powered by fossil fuels. Eventually, we will need to switch energy sources in order to keep technology running.
As consumers it is increasingly necessary to look to alternative sources that can be replaced by nature for our energy not only because they are renewable but because they are better for the environment. Currently, fossil fuels are the most commonly used energy source. Burning fossil fuels is harmful to our health and to the environment. When fossil fuels are burned for energy, greenhouse gases like carbon dioxide are released into the air. Greenhouse gases trap the sun's heat in the atmosphere, which the vast majority of scientists believe can cause to global warming. If global warming continues, polar ice caps will melt and weather patterns will change causing floods, droughts and crop failure. Acid rain is another way that fossil fuels harm the environment. When raindrops absorb sulfur dioxide in the air before falling, it damages buildings, forests and wildlife. (Walker, 2007, 1-9)
A commonly used energy source in the United States is known as biomass. Biomass is the name for all organisms on Earth and their waste. Biomass that is used for energy includes grasses, trees, plants, sawdust, woodchips, food scraps, animal waste and sewage. Biomass stores solar energy and converts it to chemical energy. When it is burned or turned into gasses or liquid fuels, energy is released. We can use this energy for heating, cooking, lighting, powering vehicles and producing electricity.
When biomass breaks down it creates a type of gas called biogas. Biogas contains methane, carbon dioxide and hydrogen gases. It burns cleaner and more efficiently and is used for heating, cooking and producing electricity. Biofuels are liquid fuels that are made from plants. Many biofuels can be used in place of gasoline and diesel to run our technology. There are five types of biofuel: methanol, butanol, biodiesel, ethanol and bio-oil. High oil prices and the drive for renewable energy have lead to their development. (Walker, 2007, 1-15)
