Space Zoo Patrol – Hydro Power

By Bree Mendlin, Director, Hydropower Foundation

Background

What is this technology called? Hydropower (or hydroelectric power)
How does it work? Creates electricity from the power of falling water.
Hydropower is a term used to refer to electricity that is produced by harnessing the kinetic energy of flowing water with the flow created by gravity. Hydro – Clean Energy Ideas (clean-energy-ideas.com)

To generate power, the water from a river is captured behind a dam, then released through a turbine in the powerplant at the bottom of a dam that spins a generator and creates electricity.

The energy-producing potential of a hydropower plant depends on the difference in elevation between the reservoir (forebay) and the water below the dam (tailwater) and the volume of water available for release. The greater the volume of water stored in the reservoir and the greater the difference in elevation, the more potential for energy production.

In power generation, water must fall from a higher elevation to a lower one to release its stored energy. The difference between these elevations is called head.

Dams are divided into three categories:

high-head (800 or more feet)
medium-head (100 to 800 feet)
low-head (100 feet or less)

Some plants may operate as a medium-head plant part of the year and as a low-head plant other parts of the year, depending on the amount of rainfall and snow melt.

Who invented it? And when and where?
Lester Allan Pelton was an American inventor who is recognized as one of the founding fathers of hydroelectric power due to his invention of the Pelton Wheel, which is also often referred to as the Pelton Turbine or Pelton Impulse Turbine. Born in Vermilion, Ohio on September 5, 1829, Pelton grew up in a rural setting working on the family farm and attending the local school. He would relocate to California in 1850 during the time of the gold rush where he would become both a carpenter and millwright. Pelton would make his “accidental” discovery sometime in the 1870’s before going on to invent the Pelton Wheel. Lester Allan Pelton later died on March 14, 1908 in Oakland, California and was buried at his family site in Vermilion, Ohio. (The Invention of Hydroelectricity – Clean Energy Ideas (clean-energy-ideas.com)

Hydropower/STEM/Resources/Educator Resources | Open Energy Information (openei.org)

Advantages

What are the environmental advantages?

Because the fuel for hydropower is supplied by nature’s own self-renewing hydrologic cycle—rain and snow filling the rivers, rivers rushing to the seas and water evaporating again to form clouds—it is an environmentally clean, renewable, and economical energy source.

Hydroelectric powerplants use renewable resources. Hydropower does not contribute to air, land, or water pollution.

What are the life cycle financial advantages?
Hydroelectric generation is an economical, renewable-energy source that

has been proven safe and nonpolluting. Because of the hydrologic cycle, it is the

most efficient converter of energy presently available and can provide energy upon a moment’s notice.

Hydropower generators have low outage rates and low maintenance and operating costs.

Hydropower generators have a long life expectancy. (Western Area Power Administration)

What jobs are created?
Hydropower creates jobs in design, manufacturing, installation.

Specifically, there are Operators, Journeymen(or women), Machinists, Welders, Project Managers, Engineers of all kinds, IT specialists, Marketing Managers and Communications Managers.

Energy Production

How efficient is this technology?

Hydro turbines can provide electricity at approximately 90% efficiency. They can be operated automatically and by remote control.
How many units are needed for 1 house or 1 community?

A large dam (such as the Hoover Dam between Arizona and Nevada) can provide electricity to 1 million homes. A micro hydro system can be built for 1 house.

What percentage of total energy usage does this technology provide today?
Today hydroelectric plants use water power to produce seven percent of the nation’s electrical supply.
What percentage of total energy usage (US, world) could this technology provide? What geographical areas can this be used in?

Currently, we’re using only a part of hydropower’s potential. Studies show that many

potential sites for conventional hydropower could be developed. If all these sites could be used, hydropower output might double. However, not all these sites can be developed. Unfavorable terrain eliminates some; society’s concern about the environment eliminates others. Public resistance to building dams that would flood scenic or agricultural land is increasing. Sites for new, large dams are becoming non-existent. Other ways to increase hydropower output include:

Increasing output at existing plants
Using pumped storage systems
Improving existing equipment at many existing hydropower plants to increase capacity and, sometimes, lower generating costs—known as “uprating,” generators in this way can made make the most of available stored water, increasing output.

Adding generating units at existing plants

Engineering / Mechanical

Two types of hydropower plants exist. The first is a run-of-the river plant that uses little or no stored water to provide flow through the turbines. Seasonal changes in stream or river flow and weather conditions affect the plant’s output.

The second type, a storage plant or reservoir (dam), offers a more constant supply of electricity. A dam on the river stores the water flowing down from the mountains, creating a reservoir. This manmade lake acts much like a battery, holding the power of water in reserve.

How is it manufactured?

Primarily, hydropower dams are constructed with steel and cement.

Education

What classes should I take in school to work on this technology?

Any STEM type class would be beneficial to this industry. However, the hydropower industry also needs accountants, communications majors, and Human Resources professionals.

A large hydroelectric dam
How a hydroelectric power plant works
A backyard micro hydroelectric plant