Hydroelectrical power!
Hydro energy
Hydropower is a clean, renewable and reliable energy source which converts kinetic energy from falling water into electricity, without consuming more water than is produced by nature. Quite simply the oldest method by which renewable energy has been harnessed by the human race. The first water wheels were used well over 2000 years ago, and the technology has since been refined to become very efficient in the production of electricity. The potential energy stored in a body of water held at a given height is converted to kinetic energy (movement energy) which is used to turn a turbine and create electricity.
In either instance, the water flows through a pipe, or penstock, then pushes against and turns blades in a turbine to spin a generator to produce electricity. In a run-of-the-river system, the force of the current applies the needed pressure, while in a storage system, water is accumulated in reservoirs created by dams, then released when the demand for electricity is high. Meanwhile, the reservoirs or lakes are used for boating and fishing, and often the rivers beyond the dams provide opportunities for whitewater rafting and kayaking.
Converting moving water to electricity
In order to generate electricity from the kinetic energy in moving water, the water has to be moving with sufficient speed and volume to turn a generator. Roughly speaking, one gallon of water per second falling one hundred feet can generate one kilowatt of electrical power. To increase the force of moving water, impoundments or dams are used to raise the water level, creating a "hydraulic head," or height differential. When water behind a dam is released, it runs through a pipe called a penstock, and is delivered to the turbine.
Hydroelectric generation can also work without dams, in a process known as diversion, or run-of-the-river. Portions of water from fast-flowing rivers, often at or near waterfalls, can be diverted through a penstock to a turbine set in the river or off to the side. The generating stations at Niagara Falls are an example of diversion hydropower. Another type of hydropower, though not a true energy source, is pumped storage. In a pumped storage plant, water is pumped from a lower reservoir to a higher reservoir during off-peak times, using electricity generated from other types of energy sources. When the power is needed, it is released back into the lower reservoir through turbines.
Hydropower relies on the water cycle
Understanding the water cycle is important to understanding hydropower. There are three steps in the water cycle:
1. Solar energy heats water on the surface, causing it to evaporate.
2. Water vapor condenses into clouds and falls as precipitation (rain, snow, etc.).
3. Water flows through rivers back into the oceans, where it can evaporate and begin the cycle over again.
Hydropower Facts
1. Hydropower uses the energy of moving water for a variety of useful applications.
2. Hydroelectricity generates electricity by harnessing the gravitational force of falling water.
3. In 2006, hydroelectricity supplied around 20% of the world’s electricity.
4. Most hydroelectric power stations use water held in dams to drive turbines and generators which turn mechanical energy into electrical energy.
5. The largest hydroelectric power station in the world is the Three Gorges Dam in China.
6. A small number of countries, including Norway, Canada, Brazil, New Zealand, Paraguay, Venezuela and Switzerland, produce the majority of their electricity through hydropower.
7. Hydroelectricity is a renewable energy but the building of the large facilities needed to make it can have negative effects on the environment.
8. Hydropower has been used to power watermills for thousands of years although cheap electricity has largely made them obsolete in modern times.
9. The most common type of watermill grinds grains into flour.
10. Tidal power is another form of hydropower, it uses the energy of tides to create electricity.
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