What is Hydroelectric Power?

Inspire Clean Energy

Oct 31, 2016

10 min read

category: Clean Energy 101

For thousands of years, people have harnessed the energy contained in running water and used it to perform useful work. For example, water wheels and water mills for processing grain were widely used over 2,000 years ago in ancient Greece. They were also used during the Han Dynasty in China and in Imperial Rome.

What is hydroelectric power?

Hydroelectric energy is a form of energy that utilizes the power of flowing water to generate electricity. It is one of the oldest methods of harnessing energy as well as one of the cleanest and most renewable.

Benefits of hydroelectric power

Hydroelectricity has many benefits, including the following:

  • It is accessible. In fact, many renewable energy companies are turning to hydroelectric power to provide their customers with an energy source that is reliable, predictable, and responsible. Renewable energy companies like Inspire are proud to offer their customers energy generated from sources that are not harmful to the planet. Home hydroelectric power is a responsible choice to make, as it makes use of an energy source that can guarantee longevity with a minimal impact.
  • If you want to learn more about powering your own home with clean energy, click here.
  • It is a renewable source of energy. In other words, it is sustainable because it is the result of a natural process that is ongoing. Because rain will always fall and rivers will always flow, hydroelectricity is a much more renewable energy source than fossil fuels, which will eventually run out.
  • It’s flexible: hydroelectricity still thrives during peak energy demand periods because rainwater can be reused. The flow of water can be altered to meet these demands without compromising the quality of the energy produced.
  • It does not cause harm to the environment. It does not cause greenhouse gas emissions and reduces our reliance on energy sources that do.
  • It helps prevent flooding. The reservoirs used to harness hydroelectricity help to control the flow of rivers, thus preventing flooding.
  • It’s a steady source of energy. Unlike gas, fossil fuels, solar, and wind power, the availability of hydroelectricity does not fluctuate, but rather remains continuously available.

Drawbacks of hydroelectric power

It’s important to note that while there are many advantages to the use of hydroelectricity, there are a few disadvantages:

  • It can impact marine life. Fish like salmon rely on rivers to spawn, and this natural instinct is hindered when dams are built. Hydroelectric dams can also alter the oxygen levels in a river, which can also affect the health of local fish.
  • It can displace people. Some communities have been displaced due to the building of a reservoir, and while they are nearly always compensated for relocating, it’s never ideal for people to have to leave their homes. However, this is not a hugely common occurrence, and these dams are typically built in non-residential areas.

History of hydroelectric power

Major innovations began in the mid-18th century, during the early days of the Industrial Revolution.

In 1753, a French engineer named Bernard Forest de Belidor published his seminal work, Architecture Hydraulique1. This work described both vertical and horizontal-axis hydraulic machines, and laid the groundwork for future innovations in hydropower. As the Industrial Revolution progressed, water was a key power source for many new inventions, notably Richard Arkwright's water frame for spinning cotton fibers.

In 1878, the very first hydroelectric power setup was used to power a single arc lamp. By 1881, Shoelkopf Power Station Number One near Niagara Falls had begun to produce electricity on a mass scale. Throughout the 20th and early 21st centuries, continuing technological improvements have helped establish hydroelectric power as a core element of an ongoing movement toward renewable energy solutions.

How does hydroelectric power work?

Hydroelectric power is harnessed through the use of flowing water, which spins turbines. These turbines then turn a shaft that is connected to an electric generator, which is where we get our energy from. Hydroelectric dams direct the water downward through the turbine, and as the water gains speed, this energy enables the maximum production of energy.

How does a hydroelectric power plant work?

Hydroelectric power plants are an important source of electricity in the United States.

Most hydroelectric power plants feature a reservoir, a gate that is designed to control how much water leaves the reservoir and an area where the water finally flows downward.

Hydropower is created when a flow of water is forced through a hydraulic circuit, or a draft, connecting two points at different heights. Here, the water gains speed as potential energy is partially converted into kinetic energy. This kinetic energy is then transformed into mechanical energy, and finally electricity.

Hydroelectric power plants are an important source of electricity in the United States. Today’s water power plants come in many sizes, from the massive Hoover Dam to small - scale projects that harness water flows in drainage ditches or irrigation facilities.

In a hydroelectric plant, natural water flows provide a source of energy that can be converted into electricity. Drought conditions notwithstanding, where water flows continuously, hydropower is a renewable resource. There are a few different types of hydropower facilities, all of which are based on the kinetic energy of moving water:

  • Impoundment Facilities Impoundment facilities use a dam to store water from a river in an artificial reservoir. As water is released from this reservoir, it flows through and spins and turbine, which activates a generator that produces electricity.

  • Diversion Facilities This type of hydroelectric facility channels part of a flowing river through a canal, either with or without an accompanying dam.

  • Pumped Storage Hydropower Pumped storage facilities are designed to store electricity that is derived from other energy sources, such as nuclear power plants or wind farms. Water is pumped uphill from one reservoir into a second reservoir at a higher elevation.

When local demand for electricity is low, pumping from lower to higher stores energy. When demand is increased, water is released back into the lower reservoir, where its motion powers a turbine that generates electricity. Like a battery, pumped storage allows unused energy to be utilized at a later time.

Is hydroelectric power renewable?

Hydroelectric power is a source of renewable energy. As a way of generating electricity, hydropower has several key advantages that contribute to its widespread usage:

  • Hydroelectric power does not contribute to air pollution. Since it derives energy from flowing water, and does not require the combustion of any fossil fuels, it does not release greenhouse gases and other harmful air pollutants.

  • Hydroelectric power is highly local, reducing dependence on outside sources of fuel.

  • Hydroelectric power is renewable.

  • Impoundment hydroelectric plants, in particular, create recreation areas as a byproduct. The reservoirs created by these projects can be used by people for swimming, fishing, and boating.

  • Hydroelectric plants generate power to the grid immediately. This means that they can very quickly go from no output to maximum output. During electricity outages and shortages, they provide a crucial backup.

  • Hydropower facilities can be beneficial for flood control, irrigation, and maintaining the water supply.

Amount of energy produced by hydroelectric power

58 power plants throughout the Western United States produce an average of 42 billion kilowatt- hours each year, which is enough to meet the residential needs of almost 15 million people. To put that into context, this would be the electrical energy equivalent of around 72 million barrels of oil.

Cost of hydroelectric power

As well as being a sustainable energy source, hydroelectric power is also a cost- effective one. Because home hydropower is so reliable, clean, and affordable, it’s one of the energy sources we purchase for our customers.

Not only does this allow our customers to harness clean energy for their home, but it allows us to offer energy at a fixed price. If you’d like to find out more about how you can use hydroelectric power and other renewable energy sources by switching to clean energy, click here.

Environmental impacts of hydroelectric power

The impact a hydroelectric plant has on the environment varies from case to case. Typically, a hydroelectric plant does not discharge pollutants into the atmosphere and is one of the least directly harmful energy sources available. However, as with any new energy source, there is a certain amount of digging and drilling required to harness it. This drilling may be responsible for the release of methane into the air, but in general, the continuous use of hydroelectric plants is not harmful to the environment.

What is hydroelectric power used for?

Before the discovery of steam power and electricity, hydroelectricity was responsible for powering grain and lumber mills. Today, it is used for several purposes, including the powering of homes and larger buildings. It also serves as an excellent back-up option when other energy sources deplete or fail. It is often relied on in power shortages and other disruptions.

Is hydroelectric power good or bad?

Of course, no energy source is entirely flawless, but hydropower is extremely close. Overall, there seem to be more advantages to hydroelectric power than disadvantages.

Hydroelectric power is renewable as it comes from a resource that will never deplete.

Hydropower dams leave the wildlife in surrounding areas relatively unharmed and do not require a huge amount of maintenance.

Similarly to wind energy and solar power, hydroelectricity is a very safe option when it comes to the choices we make for our planet. It’s also a much more efficient way of harnessing energy than coal power, for example, which is only about 33-40% efficient.

Disadvantages of hydroelectric power

Despite its many advantages, hydroelectric power is not without its drawbacks. One of the foremost concerns is that these facilities disturb natural water flows, and may disrupt local riparian ecosystems. In areas prone to drought, the ability to use hydropower facilities can be diminished when the water supply is low. Despite being an ultimately renewable resource, most of the suitable existing reservoirs for hydropower are already in use, meaning that it may become difficult, (and not environmentally prudent,) to construct new hydroelectric plants in the future.

The future of hydroelectric power and alternatives

There is no doubt that the future of energy lies in renewable sources, for many reasons. Renewable energy sources provide the planet with a better chance of sustaining itself over longer periods of time. Using renewable energy sources ensures that in centuries to come, the damage done to the ozone layer will have been slowed down and global warming will not be such an urgent issue.

The leaders of the world have noted this, and many countries have pledged to become carbon neutral. The European Union has set a goal to reduce its greenhouse gas emissions by 80-95% over the next 50 years, and many countries have followed suit.

We all need to do our part to protect the environment by choosing and increasing the demand for green energy. When you join us, you do just that. We’ll supply your life with green renewable energy that doesn’t damage the planet.

If you’re looking for a quick and easy way to make an impact, sign up for a 100% clean energy supply plan for your home.

Not sure if renewable energy is right for you? Read some of Inspire Clean Energy’s reviews to see how we've helped customers make the switch.

  1. www.britannica.com/topic/Architecture-hydraulique

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