Wednesday, October 15, 2014

Water As A Renewable Energy Source

Water as a source of power and energy it not a new concept. The use of water current to accomplish such tasks as grinding grain at a mill dates back hundreds of years.

Power from water, called hydro power or hydroelectric power, is yet another renewable source of energy. Since water is about 800 times denser than air, even a slow flowing stream of water can yield considerable amounts of energy. 

The most common type of hydroelectric power plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, which in turn activates a generator to produce electricity. Hydroelectric power doesn't always require a large dam to be built. Some hydroelectric power plants use a small canal to channel the river water through a turbine.

Another type of hydroelectric power plant, called a pumped storage plant, can even store the power that is produced. It is then sent from a power grid into the electric generators. The generators then spin the turbines backward, which causes the turbines to pump water from a river or lower reservoir to an upper reservoir, where the power is stored. To use the power, the water is released from the upper reservoir back down into the river or lower reservoir. This spins the turbines forward, activating the generators to produce electricity.

These types of hydroelectric plants can produce enough electricity to power entire towns, but small or micro-hydroelectric power systems are enough to produce enough electricity for a home, farm, or ranch.

Although using hydroelectric power seems like an immense benefit to the world, there is actually much debate over its use and the production of new hydroelectric plants. Some pros and cons are listed below:


Low Cost of Energy - Existing hydroelectric plant can produce electricity at a cost of $0.0035/kWh or between $0.015/kWh to $0.08/kWh for new construction.

Clean Energy -
Hydroelectric power uses water as its fuel instead of things that we would generally consider a fuel, which creates no harmful emissions or chemicals in the air or water.

Constant Power -
Hydroelectric power is generated by moving water, which takes advantage of the constant flow of water in rivers and other waterways.

Demand Matching -
Impoundment plants can better match demands by using generated electricity to pump water into the reservoir during periods of low electricity demand and release it to generate additional capacity during high demand periods. Similarly, it could also be used to add peaking power plant capacity.

Recreation - Impoundment plants can add recreational opportunities to area communities by offering a body of water that could be used for a combination of activities such as fishing, boating and swimming.

Low Ongoing Costs - Once built, hydroelectric plants have very low operating costs. Hydroelectric also requires few replacements over its long life, as there are few parts to a hydroelectric plant (concrete walls and pipes and a turbine).

Versatile - Hydroelectric plants can be customized to fit water availability. Small systems can be set up to power a house or farm or scaled up in size at large sites as a commercial power plant.


Droughts - Low water levels and droughts can negatively impact the amount of electricity generated. These low levels can also effect surrounding habitats.

Marine Activity - Impoundment plants can prevent fish from moving upstream by the dam and downstream by the turbines. To accommodate, fish ladders and an open area in the dam can allow fish movement.

High Construction Cost - Impoundment plants have high capital costs due to the construction of the dam, which creates a longer payback period resulting in larger hurdle for construction approval.

Relocation of Wildlife - The installation of a dam could require humans and animals living near the reservoir construction area to move.

Hydropower and hydroelectric plants have proven to be a great source of energy. As we have seen, wind and water are two renewable energy sources readily available to us if we harness and use it responsibly. For more information on energy sources and recycling options visit

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