Human and Animal Power, and Piezoelectrics

Numerous countries around the world still rely on human and animal power for their daily needs, hence the importance of describing the various energy calculations from human and animal power. These two are what some authors would call the “forgotten renewables.” They are not forgotten in this textbook. Some nonprofit organizations still hold gatherings every year to discuss educational and networking opportunities to harness these renewable energy sources. The advantages and disadvantages of using either animal or human power are discussed in this chapter. While mechanical tractors are now the predominant power source in developed countries, these high-power-consuming agricultural inputs still rely on fossil fuels. Some ergonomic factors are discussed to improve both the harnessing of human and animal power. Since the power output of humans and animals is rather low, the concept of piezoelectric power is discussed in this chapter. These devices have electric charges in response to mechanical pressure or cyclic movements and hence are ideal sources of energy for other human power needs, such as those needed for mobile phones. There are naturally occurring crystals with piezoelectric behavior that are now continually being mined for small-scale energy production and use. Numerous applications are discussed in this chapter. The charging of cell phones could become sustainable in the future if the full potential of piezoelectric energy systems is harnessed. They may also be used as sensors or tiny actuators for massive machines and operations.