Hydropower utilizes different forces that are created by moving water in order to generate power for a number of purposes. It is also referred to as hydroelectric power, or simply as water power. Hydropower can be used to generate electric power or also to create mechanical motion that runs machines for a variety of needs. Unlike many other sources of energy, such as fossil fuels, water power supplies a constant source of energy that cannot be depleted.
There are different types of naturally occurring motions of water that can be used for hydropower. The main occurrence is water that flows along a river, or down waterfalls, where the force from the water flowing from a higher place to a lower place is used to generate power. Much research is taking place that explores the use of waves and tides as another source for hydroelectric power. For example, a gyroscope floating on waves can be used to drive pistons with the rise and fall of water levels, or other devices can utilize the waves to compress air, which then moves a turbine to produce energy.
Rivers were first used for water power, where wheels were designed to turn from the force of the water in order to operate mills and various types of machinery. Dams, mainly used to produce electricity, are often built alongside other types of power plants, and can be used to regulate the amount of water that flows through them to produce different amounts of power. It is not completely necessary to build a dam for this type of hydropower, and damless hydro plants, as they are referred to, will usually utilize a smaller portion of a river or stream.
There are many sources of hydropower that have yet to be developed throughout the world, especially as other sources of energy become depleted. While more environmentally friendly than other sources, hydropower is not without its issues. Dams can have a negative impact on surrounding ecosystems, such as lower populations of fish as well as a reduction in the quality of the water itself. Because of this, hydropower plants must be built with the environment in mind, with safeguards to restore any losses that they may incur, along with constant monitoring of environmental impacts.