Hydroelectric energy is as we all understand one of the five forms of Renewable Energy Sources, RES, and as the current facts and figures indicate, Hydroelectric energy is the number one Renewable Energy Source. It is one of the 3 forms of water energy or hydro energy as it is otherwise known. The other two forms are the Tidal Energy and Wave Energy.
Hydroelectric Energy is the power from either falling or moving water. Hydro is the Greek word for water. Falling water has gravitational energy which when captured it is converted into useful energy to produce electricity or to turn the mills, as it was the case in the ancient Greek and Roman times.
Hydroelectricity is the electricity produced from hydroelectric power.
As it is the case with all forms of energy, Hydroelectric Energy has both advantages and disadvantages. In this case we will present the Pros and Cons of Hydroelectric Energy (Power), from data we have gathered from various sources, in an objective way.
Hydroelectric Energy (Power) Pros
- Constant production Cost: The cost of hydroelectric energy is relatively constant and does not fluctuate due to political and other conditions. This means that electricity produced from hydroelectric power has more or less fixed cost thus enabling a sustainable economic growth in the regions depended from hydroelectricity.
- Free Energy Source: Hydroelectric energy uses water as the means to produce energy which has zero cost. Water is free and comes from the rivers or from the outflow of dams.
- Clean Energy: It is a clean renewable green energy source which does not pollute the environment with any CO2 emissions as the fossil fuel energy does.
- Renewable Energy: Hydroelectric energy as a renewable energy does not depend on finite resources like other fossil depended energy sources. After all this is the reason it is called renewable. It depends on water which is renewed constantly with evaporation and rains.
- Minimal Operational Cost: Hydroelectric energy plants require minimal staff to operate and have a long life, about 50-100 years. These are two of the reasons for the low cost of hydroelectricity produced.
- Low Failure rate: Hydroelectric plants have low failure rates thus making them a reliable and dependable source of energy.
- Variable Size: Hydroelectric plants can be built of any size so as to be accommodated in the environment prevailing in the area and they do not have a certain fixed size as it is with other types of energy. For this reason there are 3 main technologies/methods used in hydroelectric plants.
- Controllable production: If the Hydroelectric plant is associated with dam, the electricity comes with the lowest cost and if electricity is not needed the water overflow can be stopped thus saving energy.
- Manageable Production: Hydroelectric energy is a completely controllable energy source and this means that hydroelectricity can be produced as and when needed thus enabling electricity authorities to manage the peaks and valleys of their electricity demand.
- Quick start and shutdown: The time required for the hydroelectric plant to start and shutdown is much lower than other conventional power stations. While Conventional power stations take about 8 hours to start, a hydroelectric plant takes only a few minutes. This makes hydroelectric plants suitable to cover unplanned needs or to act as standby plants to handle emergencies.
- Alternative Uses: Dams which are built for the production of electricity can be also used for other activities as well such as water recreational activities or they are used to breed fish. This means that alternative economies are built around hydroelectric plants giving an economic diversification in the area and an alternative way of living for people around dams.
Hydroelectric Energy (Power) Cons
- Need of Large Areas: The first con of hydroelectric Energy is the need of a large area to build a dam in order to be able to produce hydroelectric energy from falling water. Large areas are not always available without the creation of problems and side effects.
- Destruction of the Environment: Due to the creation of large dams for the needs of hydroelectricity we have the disruption of the surrounding environment with all the relative consequences.
- Greenhouse gases: When hydroelectric plants are built in forest areas we have greenhouse gases released from the decaying trees. This is unavoidable but it may be controllable in magnitude and finite in duration.
- Risk and Threat for People: Hydroelectric energy plants cause the displacement and disruption of the life of people living in area since they are either relocated due the construction of a dam or if they live in areas of possible flooding they are relocated for security reasons.
- Destruction of the marine life: The creation of dams prevents the flow of silt, microorganisms and plankton downstream to the beaches and estuaries thus leading the destruction of the sea life in that area.
- Destruction of fish passages: The building of dams along rivers destructs fish passages which have been there for thousands of years.
- Drought: In some cases drought may affect the flow of water either to the dam or through the hydroelectric plant and thus affect the production of electricity.
- High initial cost: Although hydroelectric plants last for 50-100 years they are expensive to build even though the return on investment, ROI, may justify their construction.
Hydroelectric Energy technology used in hydroelectric plants has evolved and adapted according to the size of the plant and the magnitude of the water resources available in the area of the plant. There are 3 main technologies/methods used to build hydroelectric plants.
Hydroelectric energy is a renewable green energy source on which we can depend and invest. In USA 96% of the produced renewable energy is hydroelectric energy and about 5000 more sites in the USA have been identified as potential sites to host hydroelectric plants giving hydroelectric energy an even greater potential.