High School Earth Science: Earth’s Energy - Renewable Energy Resources — Flashcards

Solar Energy - The sun is Earth’s main source of energy, making the development of solar power a natural choice for an alternative energy resource. The sun’s energy comes from the fusion of atoms of the lightest element, hydrogen. The results of fusion are atoms of the second lightest element, helium, and tremendous amounts of energy. Some of the sun’s energy travels to Earth, mostly as visible light. The light carries the energy through empty space from the sun to Earth as radiation.    
Solar energy has many advantages. It is extremely abundant and widespread, and it will never run out. But there are problems with the use of solar energy. For example, it is not available at night and not reliable in locations that are often cloudy. However, storage technology is being developed to overcome these problems. Other drawbacks include the expense of the technology needed to use solar energy and the relatively large amount of space required by solar panels.    

Both moving air and flowing water have kinetic energy that can be used to turn a turbine and generate electricity. Using these alternative energy resources does not create air pollution or release carbon dioxide, a cause of global warming. Therefore, both energy sources are much better for the environment than fossil fuels. In addition, neither alternative energy resource will run out. However, harnessing the energy of moving air and flowing water is not without problems. Both forms of alternative energy are only reliably available in certain areas.

Specific problems with flowing water include the need to dam streams, because damming streams floods land upstream and may displace or kill living things. The reduced flow of water downstream can also create environmental problems.