Part VII: Hydropower

Part VII: Hydropower, is actually the current number one renewable resource being used in America, and with new techniques for better efficiency, it will remain number one for some time to come. The sources in this post were my always "used" Wikipedia, as well as the Foundation for Water & Energy, The United States Bureau of Reclamation, and The EERE of the United States Department of Energy with a link to their website at the bottom of this post.

Hydropower first started as early back as 100 B.C. when the Greeks and Romans used a waterwheel, which was vertical and placed a long a stream or river, for grinding corn with its gears. Running water in the stream would turn the wheel, therefore operating the mill. Milling was the main task performed with hydropower back then, and soon it traveled through Asia and the rest of Europe by 4 A.D.
As the waterwheel spread to different parts of the world, people began to try ideas to improve on it. Change in wheel orientation was one important development. The horizontal wheel laid on its side and the wheel turned from left to right. The vertical wheel stood up, turning from top to bottom. In the beginning, "millers mounted the wheel so that the center was above the water surface and the running water would turn the bottom of the wheel. Later, they would dip the wheel below water level in an "overshot" orientation." In the 18th century, John Smeaton tested both orientations and found that the overshot worked more efficiently. "In the next century, engineers perfected the waterwheel and found two improvements: curved paddles worked better and that the breasted position (where the center of the wheel lies on the water surface) made the wheel more efficient (Brit. p.334)." These developments helped people apply the waterwheel to more tasks, such as a mill where gears, shafts, and conveyors would not only grind grain but also transport the grain up, down, and sideways within a mill. In the 19th century, the water turbine slowly replaced the waterwheel due to its higher efficiency. However, waterwheels still exist throughout the world to this day.
Following the waterwheel came the water turbine, which used gravity to turn the wheel. James Francis perfected Samuel Howd's turbine by curving its blades, and today it is known as the Francis turbine. This was used for a long time in mills, but eventually steam engines took the turbines place as it's source of power. However, the Francis turbine would make a comeback as a different source of energy; hydropower.
In effort to control streams and rivers, people began to create dams much like those that a beaver makes. These structures were used to divert the water flow, or obstruct it. To store water in a reservoir, engineers constructed a gravity dam, whose weight would stop the river flow. They made these dams initially with soil and rock, but as time progressed, concrete and brick became more popular. This is because of to their ability to trap water without allowing any flow within them. At first, dams were made straight, but later they became curved to transfer the force of the water pressure to the land it gripped. The Hoover Dam is an example of this arched dam. Bracing the land on each side, it can withstand the tremendous force of the Colorado River"
When the idea of creating electric energy from water arose, the turbine was back. In 1882, the world's first hydropower station in Wisconsin produced 12.5 kilowatts of power. In the 1930's, these stations developed dramatically. A hydropower plant was established at the Hoover Dam on the Colorado River in 1936, and it contained multiple Francis turbines (which were taken over by steam engines in mills) that produced 130,000 kilowatts of power. These stations provided electricity to major cities through high-voltage power lines. Countries all over the world have followed the lead of the United States by building stations and supplying their citizens with electricity.
As one can see, the transition of hydropower as a source of mechanical energy to electric took some time, but in the end has been worth it. With hydropower expanding throughout the world, governments and environmental organizations have been trying to find common ground on the pros and cons of using hydropower.


Hydropower is currently America's number one renewable resource:
About 20% of the world's electricity is generated by using hydropower. In the United States, this resource accounts for up to 10% of the nation's supply of electricity. This 10% can be thought of in the following ways:
Hydropower produces more than 90,000 megawatts of electricity annually, which is enough to meet the needs of 28.3 million consumers.
Hydropower accounts for over 90% of all electricity that comes from renewable resources (e.g., solar, geothermal, wind, biomass).
Hydropower is generated at only 3% of the nation's 80,000 dams.
In the Northwest, hydropower is an even larger part of each person's daily life. Up to 80% of the electricity in the Northwest is produced by hydropower each year. That's enough electricity to meet the needs of 13.6 million homes. And because hydropower is one of the lowest cost forms of energy, most Northwest residents have a significantly lower electric bill than residents in other parts of the country.

Rivers, lakes and streams are nature's way of collecting water from the hydrologic cycle and carrying it back to the ocean for the cycle to begin again. Plants and animals depend on both this cycle and the rivers for survival. As human interaction with rivers increases, maintaining a balance with the plants and wildlife that also depend on the river system becomes more complex and diverse.
Throughout history, people have hunted and fished along rivers. For centuries, rivers have been used to irrigate land for crops. And for generations, paddle wheels used hydropower to harness the force of falling water. With the advent of hydropower, man could operate mills for such things as grinding grain and cutting timber. In harmony with the current, rivers also serve as arteries for passage of fish beneath the surface and all manner of boats above the surface. All of these interactions and shifting balances began before the advent of hydroelectric power production.
Hydropower came of age at the turn of the century when many technological advances were being put in place to further tap the ability of the hydrologic cycle and rivers to help meet the needs of society. Technology became available to build larger dams that could better control flooding and irrigate more land. For instance the Grand Coulee Dam, which has the capacity to generate more electricity than any other dam in North America, was built with the primary purpose of turning the Northwest into another bread basket for the nation. Along with other irrigation projects, six percent of the Columbia River Basin's yearly runoff is now diverted to irrigate about 7.6 million acres of land annually. And with the development of locks and other technologies larger and larger cargo vessels were able to navigate rivers. In the Northwest, the result is that each year about 17 million tons of cargo are carried along the Columbia and Snake rivers from the Pacific Ocean.
Using hydropower to generate electricity is part of this technological leap. The best known hydroelectric projects are associated with the large dams that have large reservoirs which generate thousands of megawatts of electricity on demand. In fact, the six largest dams in Oregon, Washington and Idaho account for 50% of available hydroelectric power in these states.
For the Northwest as a whole, there are about 160 hydroelectric projects. For the projects which use reservoirs, there are also new recreational opportunities that many people have come to enjoy. Many hydroelectric projects, however, do not use a reservoir. These are called "run-of-river" projects because they do not store significant amounts of water. Instead, they rely on the normal river flow.
Previous generations successfully harnessed this renewable resource in a manner that has developed a standard of living in a way few would consider giving up. Using rivers to meet so many needs, however, also results in significant environmental and cultural impacts. Addressing these impacts and maintaining a balance with the plants, fish and wildlife that also depend on the river has never been more difficult. This and future generations are being asked to meet this challenge.

As mentioned, dams that are part a hydroelectric project also help control flooding. And by using this renewable resource, up to 249 tons of carbon dioxide are not released into the earth's atmosphere each year since fossil fuels like oil and coal are not burned to generate electricity. Because the release of carbon dioxide contributes to environmental concerns related to ozone depletion and global warming, hydropower represents an important environmental benefit in this regard.
Hydroelectric projects, like any energy resource, do have environmental impacts. In the Northwest, the most serious concerns often relate to fish passage. The 1992 listing of sockeye salmon and three other stocks of chinook salmon (spring, summer and fall) as endangered species intensified historic and continuing debates over restoring fish runs. Releasing water to speed up downstream fish migration has been one of many measures taken to preserve fish runs. In 1994, for instance, nearly 11 million acre feet of water was made available to help juvenile salmon and steelhead migrate downstream.
Measures such as water releases, however, are being taken within the context of scientific inquiry and research that is the subject of much debate. For these reasons, the hydro industry and others continue to explore and implement several mitigation strategies that address hatchery, habitat, harvesting, and hydro operation practices. Examples of such strategies include fish screens, surface collection and bypass systems, fish ladders, strobe lights, the catching of squawfish that prey on juvenile salmon, and new turbine designs. In fact, since the 1980s over two billion dollars has been spent on salmon recovery measures by Northwest ratepayers. As these efforts continue, scientific inquiry and research findings will continue to play a central role in guiding efforts.
The hydroelectric industry, however, cannot address environmental issues, e.g., fish migration or preserving wildlife habitats, in isolation from other industries and individuals that use the rivers. Every action and every user of a river is part of the overall balance. As a result, any search for balance that considers the Northwest's interests as a whole also needs to calculate and mitigate the effects of multiple impacts. Examples include irrigation, timber, mining and the building of homes and industries near the river system. In the case of salmon, for instance, ocean fishing that captures salmon returning to the river system is part of the overall balance.

Most hydroelectric projects across the United States are licensed by the Federal Energy Regulatory Commission (FERC). Many of these licenses, which are required to operate a hydroelectric project, are coming up for renewal during the next ten years. A central piece of receiving a new license is to examine environmental impacts and include the public in both reviewing and considering mitigation and enhancement strategies regarding these impacts. For anyone interested in the river system, becoming informed and heard in these debates is vitally important.
The process for being heard, however, extends well beyond engaging with those who generate hydropower and FERC. Numerous federal and state agencies can become involved in the process. Examples include the National Marine Fisheries Service, U.S. Fish and Wildlife Service, National Parks Service, the Environmental Protection Agency, state fish and wildlife agencies, state water resource agencies and the state agency with Clean Water Act authority. Beyond this crisscrossing of government authority are many tribal governments and non-profit groups with significant interests and concerns. Examples of non-profit groups include American Rivers, the Sierra Club, Trout Unlimited, fishing and hunting associations, and boating groups.
With so many interests participating, and because the issues being addressed are often quite complex, the relicensing process often takes between five to ten years to complete. Regardless of length, becoming an early and informed participant is of benefit to all.

Tomorrow will be Part VIII: Geothermal. Have A Great Day!!

link to eere hydropower