Hydroelectric power, also known as hydroelectric energy or simply hydroelectricity, supplies about 20% of the entire world’s electricity needs – About 88% of the total electricity that is generated from renewable energy sources. In this article I’m going to explain how hydroelectric power plants work.
Where Does Hydroelectric Energy Come From?
Hydroelectric energy can be defined as a form of hydropower where the motion of running water (kinetic energy) is converted into electricity.
The water cycle is driven directly by solar energy. When the sun heats the water in the ocean, some of the water on the surface is vaporized. The water vapor rises and when it reaches higher layers of air and is cooled, the water falls down in the form of rain, hail or snow. The water flows in streams and rivers, finally reaching the sea where it again evaporates.
What is Hydroelectricity? Hydroelectric energy is potential energy that is converted to kinetic energy through the forces of gravitation, which again comes from solar energy, driving the water cycle around. To answer the question, hydroelectric energy is the result of heat energy from the sun and the gravitational forces from the earth.
How Hydroelectric Power Plants Work
By letting the water flow through turbines on their way to the sea, we can harness some of the kinetic energy of water to produce electricity. The flow and head determines the potential energy of a waterfall.
The head is the height difference between the water level in the inlet and outlet from the power plant. From the intake reservoir, the water flows down to the power station, and then into the turbine wheel.
There are several ways to generate electricity other than the conventional hydroelectric power plant. Tide power is a form of hydroelectricity that looks very promising. The basic gist of how tide power works is this:
Tidal power is the result of the moon and the sun’s gravitational influence on the ocean. Height differences between high and low tides create tidal currents in coastal areas, and these currents can be strong enough to drive turbines.
How Much Does Hydroelectric Power Cost?
The cost of hydroelectric power is dependent on a lot of factors. An important factor is that hydroelectric power requires no fuel. This results in almost no fluctuations in costs when costs of other energy sources such as oil and gas go up or down.
Hoover Dam, built in the 1930’s, is located in the Black Canyon area of Colorado River. This facility is capable of generating 2,074MW and came with a price tag of $49 million.
These plants have long lives and don’t require a lot of operators to function. Hydroelectric power plants are in most cases able to generate cheaper electricity than other alternatives. So why don’t we just mass-produce these power plants across the globe? The answer is that suitable reservoirs are limited.
There is no doubt about that we need all the clean and renewable energy we can get. Harnessing hydroelectric energy and continuing to build out hydroelectric power plants is crucial.
The future of hydroelectric energy looks promising and will only get better as new methods to harness hydropower such as tidal power becomes commercially realizable.