To complete this unit we will be studying the topic of renewable energy and investigating lessons related to solar power, water power, and wind power. I challenge you to learn the science behind these energy sources and the technologies that help make them useful. The need for energy is constantly increasing and the world has turned to alternative sources.
Solar (Sun) Power
Harnessing Energy from the sun is one goal of the Green Revolution. While the sun's energy is essentially a constant, its effect on Earth is variable due to cloud cover and time of year. Solar energy is usually broken down into two categories, active and passive solar. For this lesson, you will use a photoelectric cell also known as a solar cell. A solar cell converts energy from the sun into electricity.
Harnessing energy from our vast water resources is one goal of the Green Revolution. Water covers 70% of the Earth and is a dense fluid. Therefore, the movement of water is able to create great forces to move materials. Perhaps, the most common example of water's force is shown by all of the sediment carried in streams and in rivers as a result of erosion. Just consider the Grand Canyon alone: thousands of feet of rock has been eroded and carried away by the force of the Colorado River.
One of the alternative energy sources that appears to have great promise is wind. Wind farms have been sprouting up everywhere. Windmills have been around for a long time, they were used in Persia (Iran) as far back as 200 B.C. Wind power involves turning energy from the wind into other forms of useful energy. It can be harnessed in a number of different ways. For example, windmills create mechanical energy, sails move boats and wind turbines generate electricity.