Lets take a closer look on what hydroelectric energy is, where it is found, and the pros and cons of hydro power.
The use of hydroelectric power or even hydroelectricity dates back to Ancient Greece and China when they installed waterwheels in rapidly flowing rivers to turn millstones and other equipment. Years later, was used to power saws and other machines.
But the hydroelectric plants of today still use the same basic principles as the historical waterwheel with some variations. The difference is that we can use any moving water, flowing or falling. The force of the power will push the turbine which in turn powers a generator thus generating electricity.
Is hydroelectric energy an alternative renewable-energy?
It is green renewable electricity, because it uses the Earth’s water cycle to generate electricity. To make sure that there is a steady flow of power being produced, a dam has to be built to retain the water. If there is a need for more power, the gates of the dam are opened so water can be released. During non-peak, the gates are closed. To ensure there is water at all times, some dams have a recovery and pumping systems to the water released can be used again.
There are issues and disadvantages of hydro electric systems.
Some claim that it poses a problem for fish and aquatic plants on both sides of the dam. Because the flow of water has been altered, the nutrient rich silt which helps crops grow could be affected which is exactly what happened when the Aswan Dam was completed in Egypt. Also the construction of a dam might dam cause displacement of thousands of people and the logging of huge areas.
But there are ways to fix that and the bigger picture is that power produced from hydroelectric plants do not generate any emissions or waste which happens to be much better than operating a coal-fired power plant.
Micro, mini or small hydros would be a more acceptable alternative as they interfere much less with the river eco-system and generate power for local use rather than as a commodity for export.
These small hydropower systems are also useful for private homeowners, small resorts or farmers if they have water flowing through their property. A micro-hydropower system usually generates up to 100 KW.
But there is another way to generate hydropower in large scale and you can get water energy form the sea. This is also known as wave power or wave energy which uses changes in the air levels of sealed chambers to power turbines. When a wave rises into the chamber, the rise water pushes the air out which then turns a generator. Once the wave goes down, air flows into the turbine and back into the chamber through doors that will close.
These chambers remain afloat on the ocean and how much power it produces varies. A lot of these are used on the western coasts of Scotland, northern Canada, southern Africa, Australia, and the north-western coasts of the United States. These systems are usually small and can power a warning buoy or a small light house. The first large scale commercial wave power station was completed in Perth, Australia this year.
There is also tidal-energy. The difference with wave energy is that when the tide approaches, the water is trapped in reservoirs behind dams. When the tide drops, the water behind the dam is released thus producing power similar to a hydroelectric power plant.
This can only work if you have tides that are at least 16 feet and since there are only a few places in the planet that can do that. The worlds largest tidal power plants are located in Scotland, the UK, Canada, France and South Korea.
Lastly, you have ocean thermal energy. Here, you get power based on the different temperatures in the water. For this to work, you need at least 38 degrees Fahrenheit difference between the warmer surface water and the colder deep ocean water. Still in the trial stage, it is used Japan and Hawaii.
Job creation in the hydroelectric energy sector.
At the moment the U.S. hydropower industry currently employs up to 300,000 workers that number can increase to 1.4 million cumulative jobs by 2025. Jobs in the public, private, and non-profit sectors and can range from entry-level to professionals positions in a wide range of fields. If you are interested working with an alternative energy company you may need general as well as specialized training.
Hydropower is a green energy source. Hydro energy is safe to use and what is even better is that it is renewable.
Interesting resource: An Assessment of Energy Potential at Non-Powered Dams in the United States