Hydropower Explained: Benefits, Drawbacks, and Turbine Technology

Hydropower: Definition and Renewable Status

Hydropower is the energy obtained from the use of the kinetic and potential energy of moving water (streams, waterfalls, and tides). It is considered a type of green energy when the environmental impact is minimal and it utilizes water power without large dams. Otherwise, it is generally considered only a form of renewable energy.

Economic Benefits of Hydroelectric Power

The great advantage of hydroelectric power is the partial removal of fuel costs. The cost of operating a water plant is nearly immune to the volatility of fossil fuels such as gasoline, coal, or natural gas. In addition, there is no need to import fuel from other countries.

Disadvantages and Environmental Impact

• The construction of dams can flood large areas of important land, obviously depending on the topography of the land upstream of the dam, which could mean the loss of fertile land, depending on where they are built.
• In the past, dams have been built that have flooded entire towns. With the growth of environmental awareness, these events are now less frequent, but they still persist.
• Destruction of Nature: Dams and reservoirs can be disruptive to aquatic ecosystems. For example, studies have shown that dams along the coasts of North America have reduced populations of Northern Trout, which commonly need to migrate to certain areas to reproduce. There are ongoing studies to find solutions to these problems, such as the invention of a type of fish ladder.

Key Types of Hydroelectric Turbines

The primary types of turbines used in hydropower generation include:

• Kaplan Turbine: These are axial turbines that have the particularity of being able to vary the angle of their blades during operation. They are designed to work with small waterfalls (low head) and large flows (high discharge). (Reaction Turbine)
• Propeller Turbine: These are similar to the Kaplan turbine, but unlike the Kaplan design, they are typically not able to vary the angle of their blades (fixed pitch).
• Pelton Turbine: These are transverse flow and partial admission turbines. Derived from the evolution of ancient water mills, they use "spoons" (buckets) instead of blades or paddles. They are designed to work with very large waterfalls (high head), but with small flows (low discharge). (Impulse Turbine)
• Francis Turbine: These are mixed-flow reaction turbines. There are some complex designs that are able to vary the angle of the blades during operation. They are designed to work with medium flows and medium heads.