What is Hydroelectric Power?

hoover dam hydroelectric power

What is Hydroelectric Energy?

Hydroelectric power is a form of energy generated by the force of moving water. This process involves channeling water through turbines, which spin a generator to create electricity. It is one of the oldest and most mature methods of producing electricity that converts the natural flow of water into valuable energy.

As we delve into the world of water-powered energy, several key questions arise:

  • Types of hydropower
  • Is water a renewable energy source?
  • Is hydropower renewable or nonrenewable?
  • What are the advantages of hydroelectric power?
  • Is hydroelectric energy expensive?

These questions are crucial in understanding the sustainability and viability of hydroelectric power as a solution for our energy needs. By examining these aspects, we can appreciate how hydroelectric power stands as a testament to human innovation in harnessing natural resources.

hoover dam hydroelectric power plant

Hydropower: A Cornerstone Renewable Energy Source

Water is the lifeblood of hydroelectric power and is considered a renewable energy source due to its natural lifecycle. It is constantly replenished by the Earth’s hydrological cycle, which includes evaporation, condensation, precipitation, and runoff. This cycle ensures a steady supply of water for hydroelectric generation, making it a reliable and sustainable form of energy.

Unlike nonrenewable energy sources that can diminish over time, such as coal or oil, water is abundant and consistently available, making hydroelectric power a sustainable choice for long-term energy production.

Different Types of Hydroelectric Power

There are three main types of power generation using the force of water.

Hydroelectric Dams

It begins with a reservoir of water behind a dam. When the dam gates are opened, water passes through turbines, capturing its raw power. 

These turbines are connected to generators, which transform the kinetic energy of the water into mechanical energy. This is then converted into a tremendous amount of electrical energy. Hydroelectric power is a renewable source that provides electricity and showcases our ability to work with nature for sustainable energy solutions.

Tidal Power

Tidal power is a form of renewable energy that harnesses the energy from the rise and fall of tides to generate electricity. As the gravitational forces between the Earth, Moon, and Sun, causing the rise and fall of tides, tidal turbines, similar to underwater wind turbines, spin. This generates mechanical energy that is converted into electricity by connected generators.

Wave Power

Wave power captures energy from the motion of ocean waves to generate electricity. Devices such as oscillating water columns, point absorbers, or attenuators are placed on or near the ocean’s surface. As waves move these devices, mechanical motion or pressure changes are converted into electrical energy through turbines or generators, providing a sustainable and renewable source of power. Despite the potential as a clean energy source, wave power technologies are still in the early stages of development and face challenges related to efficiency, durability, and environmental impact.

tidal power turbine

The Environmental Impact of Hydropower

The great environmental benefit of hydropower as an energy source is that it creates electricity in a clean and controlled manner, all without the need to burn fossil fuels. This means we’re looking at a significant reduction in the release of greenhouse gases and nasty pollutants that usually come from traditional power generation. Plus, if you compare the space a hydroelectric plant occupies to, say, a wind farm or a solar field, hydro typically requires less real estate to produce a comparable amount of energy over its lifetime.

However, there are potential negative environmental impacts to the production of electricity using hydropower.

  • Creating dams involves can involve flooding a large swath of land that was previously not underwater – a serious change to the nearby landscape. This can cause the displacement of local communities or the destruction of animal habitats.
  • Changes to river flow regimes can impact downstream ecosystems and the species that depend on those patterns.
  • Tidal power systems can lead to the death of fish.
  • Wave power systems impart significant changes to coastal ecosystems and completely change the visual dynamic of the area.

The Multifaceted Advantages of Hydropower

Hydropower is not just about energy generation; it brings a plethora of advantages:

  • Reliability: Hydroelectric plants provide a consistent energy supply, with the ability to quickly adjust to fluctuating energy demands.
  • Low Operational Costs: Once a plant is established, the cost of operation is relatively low compared to other forms of energy production.
  • Longevity: Hydroelectric facilities can operate for decades, providing a long-term energy solution.
  • Recreational Benefits: Reservoirs created by impoundment hydropower can also be used for recreational purposes, such as boating and fishing.
underwater tidal power turbines

Understanding Impoundment Hydropower

Impoundment hydropower, also known as conventional hydropower, is the most prevalent and widely used form of hydroelectric power generation. This method involves the construction of dams on rivers, which create reservoirs for storing large amounts of water. 

When electricity is needed, the stored water is released through turbines, which convert the potential energy of the water into mechanical energy. This mechanical energy is then converted into electrical energy, facilitating the generation of electricity on demand. Due to its ability to respond quickly to changes in electricity demand, impoundment hydropower is considered a highly flexible and reliable source of renewable energy.

Cost of Hydroelectric Energy

While the initial costs of hydroelectric energy facilities are high due to the need for substantial infrastructure, these costs are offset over time by the low operational and maintenance expenses. Hydroelectric power plants typically have long lifespans, which can make them economically viable and often less expensive than other power sources over their operational life.

Fun Facts About Hydroelectric Energy

  • Historical Milestone: The world’s first hydroelectric power plant began operation on the Fox River in Appleton, Wisconsin, USA, in 1882.
  • Sheer Scale: The Three Gorges Dam in China is the world’s largest hydroelectric power facility in terms of electricity generation capacity, and it’s so massive that its construction shifted enough mass to slightly alter the Earth’s rotation.
  • A Greenhouse Gas Fighter: Hydroelectric power plants have helped avoid over 100 billion metric tons of carbon dioxide emissions since 1965.
  • Wildlife Creation: While dams are often criticized for their environmental impact, reservoirs created by hydroelectric plants can also become new habitats for various wildlife species, both aquatic and terrestrial.
  • Ancient Origins: The concept of using water for power dates back thousands of years, with ancient civilizations using water wheels to grind wheat into flour.
  • Longevity: Some of the earliest hydroelectric power plants are still in use today. The Hoover Dam, completed in 1936, continues to provide power for about 1.3 million people in the USA.
  • Underwater Potential: Tidal and wave power are newer forms of hydroelectric power that harness the energy found in the movements of the ocean.
  • Home to the Mighty: The Itaipu Dam between Brazil and Paraguay is one of the world’s largest operational hydroelectric energy producers, and it’s so extensive that it spans the distance between two cities.