Hydroelectric Energy Explained

What is hydroelectric energy

Hydroelectricity is basically electricity generated from the kinetic energy in moving water. It’s important to understand that the water doesn’t need to be falling, just moving! Energy created this way is called hydroelectric power or hydropower.

At present hydropower is the most popular form of renewable energy and accounts for over 80% of the electricity generated from renewables and over 20% of the worlds electricity supply.

The Scandinavian countries are big users of hydroelectric power, with Norway producing the majority of its electricity through Hydro and Iceland just over 70%.

There are many generating stations (hydroelectric dams) around the world, such as Three Gorges Dam, Boulder Dam, Hoover Dam, etc… all of which produce energy from falling water.

But energy can also be produced on a smaller scale by using the flowing water in streams and weirs. The process is relatively simple as all you need to do is set up a mill in the middle of the stream (these small power systems are capable of producing enough electricity to power a farm or ranch.)

Hydroelectric Power Plants

The most common Hydroelectric power plant uses an “Impoundment.” This is where a dam is built across a river which impounds the water behind it in a reservoir. This water is then released from the reservoir through a turbine, which spins and activates a generator which produces electricity.

Some Hydroelectric power plants even have the ability to store energy. These are known as Pumped storage plants. What happens is that power is sent from the grid into the generators. The generators spin the turbines backwards, which results in the turbines pumping water from a low reservoir to an upper reservoir. To release the energy, this water is then released through the turbines, spinning them forward and activating the generators and thus producing electricity.

Pros and Cons of Hydroelectric Power:

Pros

* It emits no harmful chemical effluents.
* Hydro plants have two to three times the lifecycle of Fossil Fuel plants
* The plants require little maintenance
* Hydro plants don’t produce CO2 (as they don’t burn fossil fuels)
* Reservoir lakes can be used to breed fish and also provide flood protection to downstream areas.

Cons

* Natural habitats can be destroyed (the three gorges dam in China displaced more than 1.2 million people and has had a devastating effect on the nearby environment.)
* Construction costs are high
* There are a limited number of feasible sites.
* Loss of suitable land for recreation and agriculture.