I. Overview
Many countries are now utilizing hydropower, including both developed and developing nations. For the developed world, it offers the opportunity to shift to renewable resources. For developing nations, and for those areas still without electricity, it presents the chance to skip over the non-renewable phase, and opt instead for a first electricity source that has the potential to be clean and inexpensive. Of course, it is only viable for countries that feature the required climate and geography to house hydro power. Where it exists today, hydroelectricity represents a renewable energy that, once developed, produces no direct waste and emits very small amounts of greenhouse gases. But, like any energy source, it has its ugly side. Lesser known, or lesser noticed alongside hydropower's many advantages, are the environmental and social impacts also associated with it. The consequences of damming are far-reaching; conversion of surrounding valleys to lakes displaces communities of both humans and animals, and slowed flow-rates can cause severe losses in biodiversity and increases in sedimentation permanently changing that area.
The Arrow Lakes Dam, part of a series of dams just outside Castlegar, British Columbia.
Canada has a century long history with hydropower, and is currently the world's third largest producer. After the industry's initial thrust in the mid to late 20th Century, development stalled in Canada, and North America in general. A combination of expense and a wave of hesitancy due to unaddressed environmental concerns seem to be the main drivers barring expansion. Though Canada is said to have untapped potential double its existing capacity, the environmentally conscious route would be to upgrade old facilities to minimize wilderness disturbance.
Refurbishment plans are popping up across the country, with or without government assistance. In some cases, as with BC Hydro, consumers are paying for the upgrades in increased electricity rates. Currently, 60% of electricity produced in Canada is drawn from hydro. Only a portion of that hydroelectricity is used in Canada; the rest is exported for profit.
II. How Does Hydroelectricity Work?
There are three different types of river-based hydroelectric facilities; storage, run-of-river and pumped hydro.
Conventional Storage Facilities
Schematic of a Turbine.
Hydroelectric power stations capitalize on the kinetic energy of falling water to produce electricity. Kinetic energy exists in any body of water that flows, by force of gravity, on a downhill slope. The amount of energy that can be generated is related directly to the amount of height change that exists. Though the planet has many naturally occurring hydro power hotspots — like rivers and waterfalls — most power plants manipulate the force of the water with dams. Man-made dams retain massive amounts of water in reservoirs, and form drastic drop-offs that enhance the kinetic energy of falling water. The contained water is used to store energy in the form of potential energy. The energy conversion process begins at the intake structure where the gates of the dam are opened, and the water unleashed into a pipeline known as the penstock, which leads to the turbine. As the water rushes down the gradient of the penstock, it gains pressure. The water strikes the turbine and forces the blades to turn. This motion in turn powers a generator.
The generator, attached to the turbine via a shaft, contains a series of magnets that spin and move past copper coils forcing the movement of electrons creating alternating current. Used water is evacuated through pipelines known as tailraces and directed back into the river, downstream of the power station.
Depiction of a conventional storage facility.
Storage hydropower offers a big advantage over many other energy producers, as it can respond to increases in demand almost immediately by releasing extra water which spins the turbines faster and generates more electricity. Power stations can also quickly bring on additional turbines to meet demand.
Run-of-River
Run-of-river facilities employ the natural flow and elevation drop of rivers. An intake structure forces water through a submerged pipeline, or penstock, which leads to a turbine. The turbine drives a generator, which then produces alternating current. Water is directed back to its initial path further down river. In run-of-river systems, the construction of dams — and their associated impacts — are avoided. This system is not without faults as seasonality in precipitation and river flow affect power output. If there is not enough water flowing through the stream to enter the penstock then no power can be produced. The lack of a reservoir causes this type of system to be unreliable for large scale power output. Long-term small scale power output can also be unreliable due to instabilities in climates. A separate article closely analyzing run-of-river power can be found here.
Pumped Hydro
Pumped hydro is a combination technology incorporating aspects of both run-of-river and conventional storage facilities. It too uses the flow of water to drive turbines, which in turn powers generators. The power station uses normal river flow, but also has a reservoir located upstream of the facility where water can be pumped and stored. During times of high production, surplus electricity is used to push water upstream to the reservoir or to high alpine lakes to prepare for future periods of high demand.
In Canada there is only one pumped-storage facility, Sir Adam Beck Pump Generating Station at Niagara Falls in Ontario. Built in 1957, the station has an output of 174 MW.
Diagram of a Pumped hydroelectric Facility.
How does hydropower compare to other energy producers?
The principle in hydroelectric systems is similar to that of many other energy sources. Many technologies, including coal-fired power plants as well as solar thermal and geothermal plants use steam to drive turbines. Hydroelectric plants use water instead. Once the turbine is spinning and the generator activated, electricity is created.
Hydropower is extremely efficient; most modern stations can convert over 95% of available energy into electricity.1 The majority of conventional fossil-fuel plants are less than 30% efficient, and evencombined cycle cogeneration plants only operate at about 60% efficiency.
III. Geography of Large Hydro
Hydroelectric developments depend upon a combination of elevation, climate and running water. It is most common for hydroelectric power stations to be located on mountain rivers at points where the elevation begins to drop significantly. High precipitation levels are needed to enhance river flow. In North America, hydroelectric plants are typically located on or around major rivers.
Hydroelectric development calls for an alteration of the surrounding landscape. When dams are built to create reservoirs, water floods out over once dry land, and a man-made lake is formed. This new body of water offers recreational opportunities like boating and fishing, however, it also modifies the natural ecosystem, a side-effect that has sparked much debate. Not only does the construction of a dam affect the encircling area, it also affects the river as a habitat for marine creatures.2 Read more about the repercussions on wildlife as a result of damming in the Environment section.
The Gordon Dam in Tasmania, Australia.
Hydroelectric power station projects are best undertaken in collaboration with local communities and conservation groups to minimize negative environmental impacts.
IV. Large Hydro Around the World
Hydropower contributed 15% of total global energy production in 2008, making it the leading source of renewable energy today.3 All other renewables combined amount to less than 3% of global energy production.4 Despite constant development, hydroelectric's contribution to world electricity production has actually decreased. The 1920s saw the height of hydroelectric's share of world energy production — at 40%. Since then, it has decreased to 30% in the mid 1950's, 20-21% in the mid 80s, and 18% in the 90s.5
China doubled its capacity between 2004-2009, and now sits as the world's top country for hydroelectric production, with 549 billion kWh generated in 2009. Despite leading the world in hydroelectric power generation (as well as being the world's top investor in renewable energy projects), China still relies on coal for over half of its energy. Brazil, the world's second largest producer, generated 387 billion kWh of hydroelectric power in 2009, followed closely by Canada with 363.4 billion kWh. 6
With the right planning, considerations, and collaborations, hydropower development can make significant contributions in improving living standards in the developing world. Approximately 1.5 billion people still lack access to electricity.7 For rural areas without electricity, small hydro is often used to replace polluting diesel generators. Displacement resulting from the flooded reservoir (the impoundment area) is a serious concern that must be handled in cooperation with local communities. Where all stakeholders are included in planning and implementation, hydropower can offer a valuable option for energy production in the developing world.
V. Large Hydro in Canada
The 2,592 MW Daniel-Johnson Dam in Central Quebec. This dam was completed in 1968 and is essential to Quebec's electricity supply.
Canada is the world's third largest producer of hydroelectricity, generating 348.1 billion kWh in 2010. 8 More than 70,000 MW of hydropower have been developed from a total of approximately 475 generating facilities across the country.9 In 2010, hydropower generated 321,061,668 MWh, considerably more than conventional steam generation at 95,415,784 MWh.10 Total utility generation emerged at 527,689,407 MWh, demonstrating hydro's 60% dominance share of Canada's electricity production. A single power plant, like the Robert-Bou
I. ภาพรวม หลายประเทศขณะนี้กำลังใช้ประโยชน์จากพลังงานน้ำ รวมทั้งประเทศพัฒนา และกำลังพัฒนา โลกพัฒนาแล้ว มันมีโอกาสจะเปลี่ยนไปยังทรัพยากรที่ทดแทน ประเทศกำลังพัฒนา และการที่ยังไม่มีไฟฟ้า แสดงโอกาสที่จะข้ามขั้นตอนไม่ใช่ทดแทน และเลือกแหล่งไฟฟ้าแรกที่มีศักยภาพที่จะทำความสะอาด และราคาไม่แพงแทน แน่นอน มันเท่านั้นสำหรับประเทศที่ต้องอากาศและภูมิศาสตร์เพื่อพลังของบ้าน ได้ วันนี้มี ขนาดถึงพลังงานทดแทนที่ พัฒนาครั้ง ก่อให้เกิดขยะไม่ตรง และ emits จำนวนก๊าซเรือนกระจกน้อยมาก แต่ เช่นแหล่งพลังงานใด ๆ มันมีด้านน่าเกลียด ข้อดีมากมายน้อยรู้จัก หรือน้อยกว่าสังเกตควบคู่ไปกับพลังงานน้ำของ มีผลกระทบสิ่งแวดล้อม และสังคมยัง เกี่ยวข้องกับ ผลกระทบของ damming มีผับ แปลงรอบหุบเขาทะเลสาบเพื่อ displaces ชุมชนของมนุษย์และสัตว์ และชะลอตัวไหลราคาอาจทำให้ขาดทุนอย่างรุนแรงในความหลากหลายทางชีวภาพและการตกตะกอนการเปลี่ยนแปลงอย่างถาวรในพื้นที่ที่เพิ่มขึ้น ลูกศรทะเลสาบเขื่อน ส่วนของชุดเขื่อนเพียงนอกแคสเซิลการ์ บริติชโคลัมเบียCanada has a century long history with hydropower, and is currently the world's third largest producer. After the industry's initial thrust in the mid to late 20th Century, development stalled in Canada, and North America in general. A combination of expense and a wave of hesitancy due to unaddressed environmental concerns seem to be the main drivers barring expansion. Though Canada is said to have untapped potential double its existing capacity, the environmentally conscious route would be to upgrade old facilities to minimize wilderness disturbance.Refurbishment plans are popping up across the country, with or without government assistance. In some cases, as with BC Hydro, consumers are paying for the upgrades in increased electricity rates. Currently, 60% of electricity produced in Canada is drawn from hydro. Only a portion of that hydroelectricity is used in Canada; the rest is exported for profit.II. How Does Hydroelectricity Work?There are three different types of river-based hydroelectric facilities; storage, run-of-river and pumped hydro.Conventional Storage Facilities Schematic of a Turbine.Hydroelectric power stations capitalize on the kinetic energy of falling water to produce electricity. Kinetic energy exists in any body of water that flows, by force of gravity, on a downhill slope. The amount of energy that can be generated is related directly to the amount of height change that exists. Though the planet has many naturally occurring hydro power hotspots — like rivers and waterfalls — most power plants manipulate the force of the water with dams. Man-made dams retain massive amounts of water in reservoirs, and form drastic drop-offs that enhance the kinetic energy of falling water. The contained water is used to store energy in the form of potential energy. The energy conversion process begins at the intake structure where the gates of the dam are opened, and the water unleashed into a pipeline known as the penstock, which leads to the turbine. As the water rushes down the gradient of the penstock, it gains pressure. The water strikes the turbine and forces the blades to turn. This motion in turn powers a generator.The generator, attached to the turbine via a shaft, contains a series of magnets that spin and move past copper coils forcing the movement of electrons creating alternating current. Used water is evacuated through pipelines known as tailraces and directed back into the river, downstream of the power station. Depiction of a conventional storage facility.Storage hydropower offers a big advantage over many other energy producers, as it can respond to increases in demand almost immediately by releasing extra water which spins the turbines faster and generates more electricity. Power stations can also quickly bring on additional turbines to meet demand.Run-of-RiverRun-of-river facilities employ the natural flow and elevation drop of rivers. An intake structure forces water through a submerged pipeline, or penstock, which leads to a turbine. The turbine drives a generator, which then produces alternating current. Water is directed back to its initial path further down river. In run-of-river systems, the construction of dams — and their associated impacts — are avoided. This system is not without faults as seasonality in precipitation and river flow affect power output. If there is not enough water flowing through the stream to enter the penstock then no power can be produced. The lack of a reservoir causes this type of system to be unreliable for large scale power output. Long-term small scale power output can also be unreliable due to instabilities in climates. A separate article closely analyzing run-of-river power can be found here.Pumped HydroPumped hydro is a combination technology incorporating aspects of both run-of-river and conventional storage facilities. It too uses the flow of water to drive turbines, which in turn powers generators. The power station uses normal river flow, but also has a reservoir located upstream of the facility where water can be pumped and stored. During times of high production, surplus electricity is used to push water upstream to the reservoir or to high alpine lakes to prepare for future periods of high demand.In Canada there is only one pumped-storage facility, Sir Adam Beck Pump Generating Station at Niagara Falls in Ontario. Built in 1957, the station has an output of 174 MW. Diagram of a Pumped hydroelectric Facility.How does hydropower compare to other energy producers?The principle in hydroelectric systems is similar to that of many other energy sources. Many technologies, including coal-fired power plants as well as solar thermal and geothermal plants use steam to drive turbines. Hydroelectric plants use water instead. Once the turbine is spinning and the generator activated, electricity is created.Hydropower is extremely efficient; most modern stations can convert over 95% of available energy into electricity.1 The majority of conventional fossil-fuel plants are less than 30% efficient, and evencombined cycle cogeneration plants only operate at about 60% efficiency.III. Geography of Large HydroHydroelectric developments depend upon a combination of elevation, climate and running water. It is most common for hydroelectric power stations to be located on mountain rivers at points where the elevation begins to drop significantly. High precipitation levels are needed to enhance river flow. In North America, hydroelectric plants are typically located on or around major rivers.
Hydroelectric development calls for an alteration of the surrounding landscape. When dams are built to create reservoirs, water floods out over once dry land, and a man-made lake is formed. This new body of water offers recreational opportunities like boating and fishing, however, it also modifies the natural ecosystem, a side-effect that has sparked much debate. Not only does the construction of a dam affect the encircling area, it also affects the river as a habitat for marine creatures.2 Read more about the repercussions on wildlife as a result of damming in the Environment section.
The Gordon Dam in Tasmania, Australia.
Hydroelectric power station projects are best undertaken in collaboration with local communities and conservation groups to minimize negative environmental impacts.
IV. Large Hydro Around the World
Hydropower contributed 15% of total global energy production in 2008, making it the leading source of renewable energy today.3 All other renewables combined amount to less than 3% of global energy production.4 Despite constant development, hydroelectric's contribution to world electricity production has actually decreased. The 1920s saw the height of hydroelectric's share of world energy production — at 40%. Since then, it has decreased to 30% in the mid 1950's, 20-21% in the mid 80s, and 18% in the 90s.5
China doubled its capacity between 2004-2009, and now sits as the world's top country for hydroelectric production, with 549 billion kWh generated in 2009. Despite leading the world in hydroelectric power generation (as well as being the world's top investor in renewable energy projects), China still relies on coal for over half of its energy. Brazil, the world's second largest producer, generated 387 billion kWh of hydroelectric power in 2009, followed closely by Canada with 363.4 billion kWh. 6
With the right planning, considerations, and collaborations, hydropower development can make significant contributions in improving living standards in the developing world. Approximately 1.5 billion people still lack access to electricity.7 For rural areas without electricity, small hydro is often used to replace polluting diesel generators. Displacement resulting from the flooded reservoir (the impoundment area) is a serious concern that must be handled in cooperation with local communities. Where all stakeholders are included in planning and implementation, hydropower can offer a valuable option for energy production in the developing world.
V. Large Hydro in Canada
The 2,592 MW Daniel-Johnson Dam in Central Quebec. This dam was completed in 1968 and is essential to Quebec's electricity supply.
Canada is the world's third largest producer of hydroelectricity, generating 348.1 billion kWh in 2010. 8 More than 70,000 MW of hydropower have been developed from a total of approximately 475 generating facilities across the country.9 In 2010, hydropower generated 321,061,668 MWh, considerably more than conventional steam generation at 95,415,784 MWh.10 Total utility generation emerged at 527,689,407 MWh, demonstrating hydro's 60% dominance share of Canada's electricity production. A single power plant, like the Robert-Bou
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