Hydraulic Energy
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At a glance |
About hydroelectric energy
Hydroelectric energy is a renewable energy source dependent upon the hydrologic cycle of water, which involves evaporation, precipitation and the flow of water due to gravity. Canada has abundant water resources and a geography that provides many opportunities to produce low-cost energy. In fact, accessing the energy from flowing waters has played an important role in the economic and social development of Canada for the past three centuries.
The history of hydroelectric energy in Canada
Canada first used water wheels to generate mechanical power that developed an industrial base in areas such as forest products, grains, and mining in the 18th and 19th century. At the end of the 19th century, hydroelectric energy contributed to the development and implementation of an electric-powered manufacturing base in Canada . Canada also started using electricity in homes and cities during this time. Newly developed hydroelectric technology used turbines and generators to convert the kinetic energy of falling water into electricity. The development of hydroelectric energy intensified during the second part of the 20th century with the development of numerous large-scale projects. These large-scale projects further contributed to the economic and demographic development of Canada . Click here for more historic details of hydroelectric energy in Canada.
Hydroelectricity and Renewable Energy Strategy
The Canadian Electricity Association (CEA) made the following statements on behalf of the Canadian electrical utilities and hydro industry:
" When most of us in the United States and Canada think of renewable energy, we think of emerging technologies like solar, wind, geothermal or biomass. In doing so, we take for granted the predominant form of renewable energy - hydropower…
...While all of these other renewables promise significant long-term opportunity, the pre-eminent renewable generating technology today and for the foreseeable future, is hydroelectricity. Whatever form that support for emerging renewables takes, the fact remains that hydro power is an established renewable technology that offers the environmental benefits associated with emerging renewable competitors at a cost-effective price, with dependable supply, and the added benefit of opportunities for continued expansion. "
Understanding hydroelectric facilities
The main components of a hydroelectric facility are the dam, the powerhouse that contains the mechanical and electrical equipment, and the waterways. Water from a lake or river is controlled by a dam. Water is released from the dam to turn turbines. The turbines drive generators that produce electricity. The figure below shows a conventional hydroelectric facility.
- Hydroelectric energy is a continuously renewable electrical energy source.
- Hydroelectric energy is non-polluting - no heat or noxious gases are released.
- Hydroelectric energy has no fuel cost and with low operating and maintenance costs, it is essentially inflation proof.
- Hydroelectric energy technology is a proven technology that offers reliable and flexible operation.
- Hydroelectric stations have a long life and many existing stations have been in operation for more than half a century and are still operating efficiently.
- Hydropower station efficiencies of over 90% are achieved making it the most efficient of energy conversion technologies.
- Hydropower offers a means of responding within seconds to changes in load demand.
Schematic sectional view of a medium head hydroelectric facility
The purpose of the dam is to create height for the water to fall and to provide storage. However, the dam must also be provided with a spillway that can accommodate and pass high flows or flood waters without overtopping the dam or reducing its safety. The flood waters come from heavy rain or rapid snowmelt on the upstream part of the basin.
If it is proposed to utilize not only the head at the dam but also the fall in the river downstream, a canal, penstock or tunnel are needed to carry the water to the powerhouse. A canal may also be needed to carry water from the powerhouse back to the river.
Understanding the types of hydroelectric development
The following figures show a few development configurations.
Development configuration
By building the powerhouse on the bank of the river, more room is made available for a spillway of adequate capacity. The facility should be arranged to take maximum advantage of river alignment and local topography.
Developing small-scale hydroelectric facilities
Small-scale hydroelectric facilities can be developed to provide electricity for a few houses or for small commercial applications. In more rugged regions of the country, small-scale facilities can be built at relatively low costs.
The benefits of hydroelectric energy
Hydroelectric systems provide the following general benefits:
- Hydroelectric energy is a continuously renewable electrical energy source.
- Hydroelectric energy is non-polluting - no heat or noxious gases are released.
- Hydroelectric energy has no fuel cost and with low operating and maintenance costs, it is essentially inflation proof.
- Hydroelectric energy technology is a proven technology that offers reliable and flexible operation.
- Hydroelectric stations have a long life and many existing stations have been in operation for more than half a century and are still operating efficiently.
- Hydropower station efficiencies of over 90% are achieved making it the most efficient of energy conversion technologies.
- Hydropower offers a means of responding within seconds to changes in load demand.
The above text was adapted from Canadian Renewable Energy Network materials. For more information, please visit: http://www.canren.gc.ca/hydro/index.asp.
Modified: 03-07-2008
