Hydrodynamic Power Offers Abundant Small-Scale Water Power Options

Flowing water carries more than 800 times as much energy as a comparable volume of air, which makes water power an appealing method for producing electricity. Even before the advent of electricity, water mills were some of the earliest systems that went beyond human- or animal-power to do work. In the electrical age, hydropower has typically been associated with big dams and correspondingly large infrastructures. Capturing the power of enormous volumes of water behind a dam allows hydropower stations to produce billions of killowatt-hours of electricity annually, comparable to other base load power plants. But like other base load plants, there is also a strong downside to big dams that makes them less than environmentally preferable. However, new hydrodynamic systems are coming along that draw power from moving water and are able to produce energy with far less environmental impact.

While pent up artificial lakes are easy to turn into massive power plants, the environmental devastation that comes from the flooding of millions of acres of land, and the disruption of the ecosystem of the river make large-scale hydropower a second-class form of green power, at best. From a carbon perspective, hydropower is certainly preferable to burning fossil fuels. But the associated damages caused by building large-scale hydropower plants — including turning flowing water into lakes and blocking the migration of fish — is such that new dams for generating electrical power are mostly off the table.There are alternatives to creating an enormous lake in order to constantly feed the turbines.

Small-scale turbines that can sit in flowing bodies of water and generate electricity could now be poised to bring a new face to hydropower. These turbines are greener since they don’t require the blockage of waterways and the destruction and flooding of land in order to be able to produce power. Hydrodynamic power works with the energy in moving water, rather than closing off waterways to build up huge reserves of potential energy stored in the water held behind giant dams. Developmental systems from several companies are now exploring the production of more modest amounts of power, but with far lower cost and with much less environmental destruction than that from the creation of dammed hydropower. Companies such as Hydrovolts Inc., Free Flow Power and Verdant Power have different systems to make use of this power, which they are testing in different parts of the country. There are also researchers who are working on other systems that can potentially take advantage of more energy available in slower moving water.

The federal government in the United States has identified this as an as-yet untapped source of power. The existing water infrastructure of the American West offers a great deal of hydropower potential, with the greatest amount found in the states of Colorado, Oregon and Wyoming. A study by the U.S. Department of the Interior’s Bureau of Reclamation found that 1.5 million megawatt-hours of renewable energy could be generated through hydropower without needing to construct new — and environmentally questionable — large-scale dams. Instead, existing waterways and reservoirs can be used to provide electricity in addition to serving water needs of the region. (For comparison, the Hoover Dam power station produces about 4 million megawatt-hours of electricity annually. Think of this as another one-third of a Hoover Dam spread out through the existing water infrastructure.)

Aqueducts and canals represent an available source of power for additional electrical generation. Particularly in the western U.S., where water management is carried out through an extensive infrastructure of constructed canals and waterways, it may be possible to provide power for tens of thousands of additional homes. Existing dams that were built for water management rather than for power generation may be able to be tapped for power production as well, through the installation of smaller scale equipment that can efficiently and cost-effectively produce power from dams that may have previously been thought too small to be useful for power generation.

To make use of this hydrodynamic power, small, in-line turbines can be installed that generate electricity from the flow of water through aqueducts and canals. The turbine sits directly in the waterway, without a dam, which means that the negative impacts to the environment, as well as the infrastructure costs to install this equipment, are greatly reduced.

Because these waterways already constrict the flow of water moving through them, a greater proportion of the energy from the water flow can be captured with this equipment. In a canal, where most of the water flow must go through the turbine, the efficiency can be as high as 60 percent. Depending on the size of the waterway and the flow rate of the water moving through it, turbines can provide electrical output ranging from 1.5 kW to 30 kW. Because many of these waterways have continuous flows of water moving through them, they are well suited to provide additional, continuous power generation for the grid.

The Bureau of Reclamation has over 47,000 miles of canals, laterals, drains, pipelines and tunnels. To find places with hydropower potential, the government study identified those locations where there was at least a 5-foot drop and where the waterway was in operation for at least four months out of the year and where the power generation potential was at least 50 kW (based upon flow rate of canal and the drop height).

One manufacturer producing turbines for in-line uses is Hydrovolts, Inc. These are reasonably small pieces of equipment. Turbines for canals and waterways are about the size of a car or small truck. Waterfall turbines can be even smaller, and will still produce a significant amount of power. They are also fairly inexpensive, with the cost of the smallest portable model starting at just $2,000. The canal-sized turbines cost from $20,000 to $40,000. While wholesale electrical rates are not great, since their output will be fairly consistent, these turbines can potentially repay their investment cost in just a few years. Initial tests of the Hydrovolts turbine were carried out in the Roza Canal in Washington State earlier this year.

(Quick back-of-the-napkin math: A turbine costing $40,000 and generating an average of 25kW over a year of operation will produce almost 220 MWh of power and earn over $10,000 at a wholesale electrical rate of $0.05/kWh. That could mean that the equipment could be paid off in four years.)

Hydrovolts turbine in the Roza Canal in Washington State:

Hydrovolts turbines also can be outfitted with different kinds of blades, depending on the flow rate of the water. This makes the system more versatile, and the same equipment can be used in different locations, with just a change of blades in order to produce the optimal yield from a given location.

While many of these channels being discussed for use are artificial waterways used for irrigation, the same technology can be used in open water rivers and streams with a sufficient flow rate. In those cases, having the waterway open to fish migration and movement is another benefit from this technology.

While the Hydrovolts turbines are being developed for very small waterways, the opposite end of the hydrokinetic power scale is also being explored with a project set in the world’s largest river. Free Flow Power is a company that is developing river flow turbines to be placed along a length of the lower part of the Mississippi River.

The Free Flow Power turbine is a 3-meter diameter multi-bladed propeller inside a housing that makes it look very much like a large jet engine. The turbine has a 40 kW rating. The first array of these turbines will be installed at a total of 25 locations along the Mississippi River and will provide a total generating capacity of 3,303 MW. Given the size of the river and the volume of water that flows through it, there is a great potential for much more energy production if this technology turns out to be effective and cost-competitive.

Unlike wind farms, these turbines are out of sight below the surface of the water. Despite their size, since these turbines will be installed below the water’s surface, they will present very little obstacle to navigation, so that the Mississippi will also continue to serve as an efficient highway for barge traffic moving goods up and down the river. This project may be just the beginning for harnessing the vast power of so much water moving through the middle of the country.

In New York City’s East River, the Roosevelt Island Tidal Energy Project (RITE) being run by Verdant Power Inc. will eventually have 30 turbines installed underwater and generating as much as 1,050 kW of electricity when the pilot project is fully installed in 2015. These turbines are considerably larger than the Hydrovolts equipment. Rather than drawing power from the narrow flow of water in a channel, these units are instead powered by the tidal flows from the ocean.

Verdant Power has another project that builds on some of the work done for the RITE project. The Cornwall Ontario River Energy Project (CORE) is installing turbines in the St. Lawrence River near Cornwall, Ontario to study how the turbines work in a river flow situation.

The turbines Verdant is developing are three-bladed, without an enclosure, and look quite similar to the now familiar three-bladed wind turbines, except for their comparatively much smaller size. The Verdant turbines are larger than those being developed by Free Flow Power; for the CORE project they are using turbines with a blade diameter of 5 meters and with a generating capacity of 60-80 kilowatts. These turbines, too, would sit out of the way of surface vessels on the bottom of the waterway. An animation from Verdant shows what a large-scale farm of these turbines might look like.

Along with these developmental systems, researchers are working on other low-velocity technologies for hydrokinetic power generation. One system, being explored by researchers at the University of Michigan is called VIVACE, which stands for Vortex Induced Vibrations for Aquatic Clean Energy. VIVACE is especially interesting because it promises to work with slow moving river flows as slow as 2 knots. Most river currents in the United States are slower than 3 knots.

The VIVACE system works with horizontal cylinders placed across the flow of the water to create a vortex as the water flows past the cylinder. “Vortex Induced Vibration (VIV) is an extensively studied phenomenon where vortices are formed and shed on the downstream side of bluff bodies (rounded objects) in a fluid current. The vortex shedding alternates from one side of a body to the other, thereby creating a pressure imbalance resulting in an oscillatory lift.” This motion of the cylinder can, in turn, be used to move a magnetic field in order to produce electricity.

The turning blades of hydrokinetic turbines are a potential concern, just as wind turbines are with birds. Part of the reporting being done with these early projects is to study potential problems with this kind of equipment. Although its development is lagging behind some of the other systems, VIVACE may turn out to be a preferable technology because it has less impact on marine wildlife. The cylinders used in this system are very slow moving (only about 1 cycle per second), and the risk of harm to any fish is therefore extremely low.

Hydrokinetic projects are appealing because the power generation is more constant than some other sustainable systems. Waterway flows can be more regular and dependable than intermittent sources like wind. Hydrokinetic power is presently an underutilized resource, but as these companies develop their technology, it is likely to become another part of the energy mix.

By Philip Proefrock@REVMODO.com



 

Hydropower Continues Steady Growth

World hydroelectric power generation has risen steadily by an average 3 percent annually over the past four decades. In 2011, at 3,500 billion kilowatt-hours, hydroelectricity accounted for roughly 16 percent of global electricity generation, almost all produced by the world’s 45,000-plus large dams. Today hydropower is generated in over 160 countries.

© Earth Policy Institute

Four countries dominate the hydropower landscape: China, Brazil, Canada, and the United States. Together they produce more than half of the world’s hydroelectricity.

© Earth Policy Institute

Much of the world’s recent growth came from China, where hydropower generation more than tripled from 220 billion kilowatt-hours in 2000 to 720 billion in 2010. In 2011, despite a drop in generation due to drought, hydropower accounted for 15 percent of China’s total electricity generation.

© Earth Policy Institute

Brazil, the second-largest producer of hydropower worldwide, gets 86 percent of its electricity from water resources. It is home to an estimated 450 dams, including the Itaipu Dam, which generates more electricity than any other hydropower facility in the world—-over 92 billion kilowatt-hours per year.

Approximately 62 percent of Canada’s electricity is generated from its 475 hydroelectric plants. The country’s enormous hydropower capacity allows for electricity export; Canada sells some 50 billion kilowatt-hours to the United States every year—-enough to power more than 4 million American homes.

Because most large dams in the United States were built before 1980, the country’s hydropower capacity has remained relatively stable in recent decades. The country’s highest capacity dam—-the Grand Coulee Dam on the Columbia River in Washington State—-was completed in 1942. Today, more than 7 percent of all U.S. electricity is supplied by hydropower. Similarly, hydropower in the European Union is relatively mature, with capacity increasing by less than one percent annually over the last 30 years. In 2011, hydropower supplied 9.5 percent of E.U. electricity generation.

© Earth Policy Institute

Among the world’s largest producers, Norway gets the greatest share of its electricity from hydropower: a full 95 percent. Other countries that get the bulk of their electricity from river power include Paraguay (100 percent), Ethiopia (88 percent), and Venezuela (68 percent). A number of African and small Asian countries also generate virtually all of their electricity with hydropower, including Bhutan, the Democratic Republic of the Congo, Lesotho, Mozambique, Nepal, and Zambia.

© Earth Policy Institute

While conventional hydropower will continue to grow as dams are completed in China, Brazil and a scattering of other countries, including Ethiopia, Malaysia, and Turkey, there exists enormous potential for non-conventional hydroelectricity generation from tidal and wave projects, as well as from small in-stream projects that will not require new dams.

Thus far, few of these hydrokinetic projects have been realized. France’s La Rance Tidal Barrage, with a 240-megawatt maximum capacity, was the first large tidal power plant. It began generating power in 1966, and is still operating today. In South Korea, a 254-megawatt project was completed in August 2011. Now the world’s largest tidal operation, it has the capacity to provide electricity for half a million people on the country’s west coast. New Zealand also recently approved a coastal hydropower project.

Wave power is also drawing the attention of both engineers and investors. Firms in France, Scotland, and Sweden, among other countries, are working to capture this emerging market. Estimates from the World Energy Council indicate that worldwide, wave energy has the potential to grow to a massive 10,000 gigawatts, more than double the world’s electricity-generating capacity from all sources today.

For additional data on the world’s energy resources, visit Earth Policy Institute’s Data Center and see the Supporting Data from World on the Edge by Lester R. Brown at www.earth-policy.org.

By Lester Brown@ treehugger.com 

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China’s Hydropower Miscalculation

                            Three Gorges Dam, A Symbol of China's Miscalculation on Hydropower

China’s Jinsha River, literally the “Golden Sands” River, could soon live up to its rich name. The approximately 2300-km long upstream section of the Yangtze River is the site of up to 25, planned large-scale (50 MW and above) hydropower projects (Caixun, May 4; Dongfang Zaobao, May 3). China’s state-run hydropower companies, local governments, and energy-hungry cities in the more developed, eastern provinces stand to profit from hydropower construction and electricity generation. Driven by Beijing’s energy and climate goals, this new dam building rush, however, will reduce China’s climate change adaptation capacity and hurt relationships with neighboring countries without providing the emission-free electricity Beijing is seeking.

China’s status as the world’s largest CO2 emitter has put increasing pressure—both domestic and international—on Beijing to curb national emissions (Climate Progress, December 7, 2011). In response, the government has laid out a set of binding targets in the 12th Five Year Plan: an 11.4 percent increase in the use of non-fossil fuel in primary energy consumption; a 16 percent decrease in energy consumption per unit of GDP; and a 17 percent decrease in CO2 emissions per unit of GDP by 2015 [1]. Now, China is looking for sources of clean, emission-free and sustainable electricity to fulfill ever-growing demand and meet renewable energy and emission targets. More large scale hydropower is wrongly thought to be one such source. Consequently, dozens of projects are planned or already under construction on a number of rivers, including 26 on the Lancang, headwater of the Mekong, 13 on the Nu, headwater of the Salween, and 28 on the Yarlung Tsangpo, the headwater of the Brahmaputra (Atlantic Sentinel, March 10; The Hindu, June 10, 2011).

The Misguided Hydropower Narrative

Addressing China’s power sector—a major contributor to national greenhouse gas emissions—is critical to reaching Beijing’s emission targets. A terawatt hour (TWh) of electricity generated in China produces on average 70 percent more CO2 emissions than a TWh generated in the United States, and China’s power sector accounted for almost 50 percent of the country’s CO2 emissions in 2009 (International Energy Agency, World Energy Outlook 2011). Developments in the power sector therefore will have a significant impact on the country’s emission trajectory.

The high carbon-intensity of China’s electricity is due to the sector’s heavy reliance on coal. Coal, a very carbon-intensive fuel, is used to generate around 80 percent of China’s electricity (China Statistical Yearbook 2011). Hydropower accounts for 16 percent of the country’s electricity generation with nuclear, wind and solar making up the remainder. Hydropower advocates argue that shifting the energy mix from carbon-intensive coal to more hydropower would benefit China’s emission targets.

This argument relies on the still widespread “clean, sustainable and emission-free hydropower” narrative. Even the United Nations Framework Convention on Climate Change tacitly supports this misconception by making reports of greenhouse gas emissions from dam reservoirs voluntary (International Rivers, December 2, 2011). Studies however have shown that hydropower can be a major source of greenhouse gas. Organic material from previously forested, but now flooded land and washed up debris, accumulates and decomposes in the dam reservoirs, thereby releasing large amounts of methane, a potent greenhouse gas. This problem particularly affects hydropower projects in tropical areas, where the vegetation is generally denser and more organic material is accumulated in reservoirs. Some hydropower facilities in tropical areas emit up to twice as much carbon dioxide per unit of electricity as coal fired power plants [2]. As most of China’s planned hydropower projects are located in densely forested, subtropical southern and southwestern provinces, new dam reservoirs are likely to become significant emission sources.

Making Adaptation Harder

The 12th Five Year Plan also addresses climate change adaptation strategies. Beijing wants to strengthen the country’s “capacity to cope with extreme climate incidents,” thereby enhancing China’s climate change adaptation capacity [3]. Yet, the construction of more dams will decrease China’s capacity to cope with extreme climate incidents, which are predicted to include more frequent and more severe record floods and droughts [4].

First, the impacts of large-scale dams on wetlands and human settlement patterns limit China’s adaptation capacity—the ability to moderate potential damages or cope with the consequences of climate change—as they expose millions of people to climate change related risks. To maximize power production, dams store water during the wet season and release it during the dry season. This alteration of natural river flow patterns impacts the health of natural flood storage systems, such as downstream wetlands, lakes and marshes, often leading to their disappearance. Thus, dams reduce the frequency of smaller floods, but also decrease or eliminate wetlands’ natural capacity to absorb water and thus mitigate severe floods.

In addition, dams enable the conversion of wetlands to agricultural farmland and provide downstream cities with electricity and water for irrigation, industrial and household purposes, enabling and encouraging their development and growth. Hydropower development therefore contributes to population growth in downstream areas, which simultaneously increases the number of people at risk of dam failure as changing precipitation patterns could lead to floods that may exceed the storage capacity of dams upstream.

The controversial Three Gorges Dam is a case in point. With a capacity of 22.5 GW, the dam can generate up to 84.7 billion kWh of electricity for cities in central, southern and eastern China, including the downstream metropolis of Shanghai (Xinhua, October 26, 2010). While its reservoir supplied the population in the middle and lower Yangtze with a steady source of water, it also contributed to the drying up of Dongting and Poyang Lake, two of China’s largest freshwater lakes, during the 2011 drought (Shanghai Daily, June, 2, 2011; China Three Gorges Corporation, August 7, 2009). Although the dam withstood its first major flood test in 2010, whether the Three Gorges Dam will be able to contain future, possibly worse, floods is uncertain (Xinhua, July 20, 2010). If it fails, downstream residents will not be able to rely on natural floodplains to mitigate the impact with possibly disastrous consequences for life and property.

Second, the operation of large-scale dams exacerbates droughts in downstream areas. In theory, reservoirs could provide short-term drought relief, by releasing stored water for use downstream. Yet, below a certain water level, the primary objective of hydropower operators—maximizing electricity generation—suffers. The fact that the central government had to order the China Three Gorges Corporation to release water from the reservoir to alleviate the severe drought downstream in 2011 suggests that hydropower operators are likely to put power generation ahead of drought relief (South China Morning Post, May 25, 2011).

Third, dams make it harder for coastal cities to adapt to rising sea levels. As freshwater is held back in reservoirs upstream, natural water outflows at river deltas are reduced, contributing to a fall in coastal groundwater tables. Combined with rising sea levels, this makes coastal delta regions more susceptible to saltwater intrusion, which contaminates coastal freshwater aquifers and makes water unfit for human consumption [5]. More dams could exacerbate future saltwater intrusion challenges for many coastal Chinese cities brought on by rising sea levels. Shanghai, located in the Yangtze River Delta, is already experiencing saltwater intrusion, which research has linked to variations in water discharge from the Three Gorges Dam (Scientific American, October 13, 2009) [6].

Lastly, the expensive and long-lasting nature of hydropower infrastructure makes it difficult or impossible to adapt them to future changes in the environment, agricultural and economic activities and human settlement patterns.

Large-scale dam construction is very costly. The record-setting Three Gorges Dam cost approximately $25 billion. Even smaller projects like the planned Xiaonanhai Dam on the Upper Yangtze cost up to $5.6 billion (China Dialogue, March 9, 2011). China Post Securities analyst Shao Minghui estimates the hydropower sector will need around $136 billion in infrastructure investment by 2020 (Shanghai Daily, January 6, 2011). The sheer size of this kind of investments often prompts path dependency—the preference to continue even if better alternatives are available—as investors look to realize promised returns on investment, and local governments are unwilling to admit that there may have been better development alternatives.

Furthermore, the design of hydropower dams is based on historical and current river flows. While their lifespan ranges from 50 to 100 years, climate change is likely to alter future river flows within decades. Modifications to existing large-scale dams to accommodate these changes, however, are either technically infeasible or very expensive. Dried up rivers or changing river courses could turn dams into stranded assets, because they, unlike solar or wind installations, cannot be moved. A drought in 2011 caused a 28 percent reduction in hydropower output, resulting in 1000 factories and companies in Guizhou suspending operations and showing even temporary reductions in water flows can result in significant power shortages (Xinhua, August 24, 2011).

Damming International Relationships

China’s dam building rush will have negative impacts on relationships with neighboring countries. Furthermore, national hydropower companies’ overseas venture may harm China’s international reputation.

China’s territory encompasses parts of 18 of Asia’s major international river basins. Moreover, China’s position along these river basins is predominantly upstream, and, in the case of the Brahmaputra, the Mekong, and the Salween, at the source. Hydropower development in China therefore has international impact, and affects China’s relationships with its downstream riparian neighbors, including Bangladesh, Cambodia, India, Laos, Myanmar, Thailand and Vietnam. The construction of cascades of large-scale hydropower dams along rivers in China’s territory affects the water quantity and quality downstream. While the exact extent of these dams’ negative impact on water availability, fish populations and consequently downstream populations may be unknown, the existence of such effects is certain.

Upstream dams also provide some control over the timing and amount of water flow in the rivers affected. People downstream therefore may feel that Beijing rather than nature controls their water and their welfare. Admittedly, upstream China does not control the entire water flow of these rivers as water volumes generally increase along the river. Yet, as river basins are highly complex, and the precise amounts of water inflows at particular sections are hard to measure, citizens of countries downstream may perceive China to be in full control. Indian newspapers, for example, write of China’s “superior upper riparian positions” and “unique position of controlling international rivers,” and suspect the country of secretly diverting water from the Yarlung-TsangpoRiver (Hindustan Times, March 2; India Today, August 19, 2011). In 2010, when severe drought hit the Mekong, farmers and fishermen in countries downstream blamed China and its hydropower stations for the disaster, despite China’s assurance that it collected only “four percent of the river’s water” (China Daily, April 9, 2010; New York Times, April 1, 2010). Regardless of the validity of these suspicions, given China’s geographic position, more hydropower construction will further strain relationships with already apprehensive neighbors and nations downstream.

Furthermore, for about a decade now, Chinese state-run hydropower companies have increasingly looked abroad to market the experience and technology gained in domestic projects. More domestic dam building is likely to make these companies even more internationally competitive as they gain further technical expertise and financial resources. Yet, the nature of many of these overseas ventures may harm China’s international image.

As Europe and North America have turned away from the construction of large dams, Chinese companies armed with newfound skills have sought projects in other Asian, African and South American nations—many of which lack strong legal and political institutions, environmental and regulatory oversight and suffer from corruption and instability. Chinese banks and companies currently are involved in about 300 projects in 66 countries, including Angola, Burma, Cambodia, Ethiopia, Iran, Sierra Leone and Sudan (International Rivers, May 1). Due to these problems, many of the projects are high risk, involve human rights violations by local governments and fail to be built according to international environmental and safety standards. In the long run, this reflects negatively upon Chinese companies and ultimately the country as a whole.

The Myitsone Dam on the Irrawaddy in Burma illustrates this point. Located in Kachin State, home to a strong separatist movement and site of frequent, armed clashes between the Burmese military and the Kachin Independence Army, the project was supposed to be financed and built by the China Power Investment Corporation, before President Thein Sein suspended it in 2011 (The Irrawaddy, September 21, 2011).Myitsone holds a special cultural and religious significance for the Kachin, who revere the area as the birthplace of their culture. Should construction move forward, the result is likely to be viewed as a symbol of China’s lack of cultural sensibilities and disregard for local minority groups (China Dialogue, March 28, 2011).

Conclusion and Recommendations

Beijing’s focus on hydropower to achieve energy and emission targets largely ignores or downplays large-scale dams’ negative impacts on the climate, the country’s adaptation ability and relations with neighbors as well as China’s international reputation. Yet, there are a range of alternatives to large dams.

Greater focus on energy efficiency could provide huge energy savings. For example, China’s cement industry alone could achieve primary energy savings of 23 percent through the implementation of international best practices [7]. In the power sector, the government could accelerate its efforts to replace small, inefficient power plants, with more efficient supercritical and ultra-supercritical power plants, as well as combined heat and electricity cogeneration plants. More efficient appliances and lighting could reduce household electricity consumption, a growing part of China’s total consumption. This could be achieved through programs similar to Energy Star in the United States.

Additionally, all existing alternative energy infrastructure should be connected to the power grid. As of 2011, 30 percent of China’s wind power capacity, for example, was not yet connected to the grid (Xinhua, February 24). At the end of 2008, small hydropower plants numbered 50,000, many of which were built decades ago and are equipped with outdated, inefficient technology (China Daily, January 7, 2009). Prior to building new projects, existing infrastructure should be surveyed, and where necessary retrofitted with new technology to be more productive.

While less impressive in scale than highly visible mega-dams, these alternatives could alleviate expected energy shortages, and help Beijing achieve its targets without the negative consequences and future risks associated with large scale dams.

China’s status as the world’s largest CO2 emitter has put increasing pressure—both domestic and international—on Beijing to curb national emissions (Climate Progress, December 7, 2011). In response, the government has laid out a set of binding targets in the 12th Five Year Plan: an 11.4 percent increase in the use of non-fossil fuel in primary energy consumption; a 16 percent decrease in energy consumption per unit of GDP; and a 17 percent decrease in CO2 emissions per unit of GDP by 2015 [1]. Now, China is looking for sources of clean, emission-free and sustainable electricity to fulfill ever-growing demand and meet renewable energy and emission targets. More large scale hydropower is wrongly thought to be one such source. Consequently, dozens of projects are planned or already under construction on a number of rivers, including 26 on the Lancang, headwater of the Mekong, 13 on the Nu, headwater of the Salween, and 28 on the Yarlung Tsangpo, the headwater of the Brahmaputra (Atlantic Sentinel, March 10; The Hindu, June 10, 2011). 

Free Republic

Hydropower in Africa

 

Cameroon Signs $1bn Hydropower Project Deal

The Government of Cameroon and Joule Africa have entered into a memorandum of understanding for the development of the $1bn Kpep hydroelectric project in Cameroon.

The company said the project will increase the country's current installed power generation capacity by about 40% and would have an installed capacity of more than 450 MW when completed.

Located on the Katsina-Ala River in Menchum division, north of Bamenda, and near the Nigerian border, the Kpep hydroelectric project is expected to increase the power capacity, boosting economic development of the region.

Joule Africa will undertake the project with local partner Bethel Industrievertretung of Bamenda-Cameroon and European engineering firm, Lahmeyer International.

Lahmeyer International is recognised as one of the top hydro engineering firms in the world and has extensive experience designing hydroelectric projects in Africa.

Joule Africa is a member of the Joule Investments Group, a US-based developer, owner, and operator of hydroelectric power projects in emerging markets.

Demand for electricity in Cameroon is projected to triple over the coming decade, requiring about an estimated 3 GW of additional energy infrastructure by 2020.

 African Bank to Approve $100 Million for Hydro Power Plant in Ethiopia 

The African Development Bank is to approve 100 million US dollars to finance the construction of a new hydro power in Ethiopia, this September according to Lamin G. Barrow, Ethiopia Country Office Resident Representative of the African Bank.

The hydro electric power project will consist of two power plants with a total potential capacity of producing 371 MW (1680 GWH) annually.

It is expected that the project will cost more than 400 million US dollars with the African Bank financing a quarter of the projected cost and the remainder being co-financed from other financial institutions.

 

It is to be remembered that the African Development Bank is to approve a 231 million US dollar loan for the Ethiopia-Kenya power interconnection project said officials from the bank.  

The board of directors of the African Bank will be expected to appraise the project in the first quarter of the current financial before giving final approval according to Halima Hashi Ethiopian Country Program Officer for the AfDB.

The Ethio-Kenya power interconnection system is planned to provide a reliable power supply to Kenya from Ethiopian hydro electric power supplies.

The AFDB also gave a 234.5 million us dollar loan for the construction of roads in Ethiopia, linking the country to South Sudan and Kenya. The Bank made the loan to encourage trade relationships between Ethiopia and its neighbors.

 

The two roads to be financed by the African Bank are the Bedele-Metu road and the upgrade and construction on the Hawassa-Ageremariam road.

Water Power: Out with the New, In with the Old by Zachary Shahan

Solar and wind energy are well-known renewable energy options that are quickly growing in use around the world. Both have seen record-breaking growth in the past few years. Tremendous growth is projected to continue in the years to come, as well. But solar and wind won’t provide the world with all of its energy needs. They may not be ideal for some locations, and they may need to be supplemented by other energy sources in some locations.

Other than the ubiquitous wind and the tremendously powerful sun, one of the most abundant natural resources on our planet is water, and flowing water carries a great deal of energy. Just think of the feeling you had when you walked into a medium- or fast-flowing river or stream, or decided to test your strength against a breaking wave.

While wave power, tidal power, ocean thermal power, and other “water power” options exist, this article only discusses the most readily available water power option today — small or micro hydro.

Small Water Power (or Micro Hydro) Potential

New micro hydro (aka microhydro or micro-hydro) could produce 30,000 megawatts of decentralized, local power in the U.S. alone, according to a 2006 study. To put that into perspective, that’s enough power for up to about 30 million homes.

“We keep telling lawmakers that there’s tremendous growth potential in the industry. We are far from tapped out,” Jeff Leahey, director of government affairs for the National Hydropower Association, says. “We can access existing infrastructure today and build tens of thousands of megawatts in communities around the country.”

The map below shows what percentage of a state’s electricity sales could be provided from new micro hydro.

All of this small hydro potential could be tapped with “run-of-river” projects (projects not requiring dams) or projects that make use of existing dams.

“There are over 81,000 dams around the U.S. and only 2,400 of them have any electrical generating capacity,” Stephen Lacey of Climate Progress reports. “Many of the power-less 78,600 dams are close to existing infrastructure, making it easier to build and maintain a project compared with a centralized wind or solar farm located far away from where the electricity is used.”

The question, however, is what technology will be able to capture that energy and efficiently turn it into electricity for a home, business, or community.

continue @ cleantechnica.com 

Ocean Motion Could Produce 9 Percent of U.S. Electricity by John Roach

A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams.

Next-generation technologies that harvest electricity from ocean waves and tides sloshing along the U.S. coasts could provide about 9 percent of the nation's demand by 2030, according to a pair of recent studies.

The findings, which include maps of these ocean energy resources, should help guide companies looking to develop them.

"We have believed for a long time that the resource was significant and these assessments add a tremendous level of confidence what that potential is," Mike Reed, water power team lead with the U.S. Department of Energy's Wind and Water Program told me Monday. 

Today, about 6 percent of the nation's electricity comes from traditional hydropower projects, such as the Grand Coulee Dam, that direct the flow of the river through turbines to generate power.

Since such dams plug up rivers and make it difficult for migrating fish species such as salmon to reach their spawning grounds, they have lost favor in recent years. 

Looking forward, energy developers see promise in technologies that capture the energy in waves and tides off the coasts. 

Designs to do this range from buoys that harness the up-and-down motion of passing waves to turbines on the ocean floor that are spun by the ebb and flow of the tides.

The studies released earlier this month from the U.S. Department of Energy could help nudge along the development and deployment of these technologies by showing the resource is there to be captured.

continue @ msnbc 

Hydroelectric Energy is renewable.

The Sun provides the water by evaporation from the sea, and will keep on doing so.

Flowing water creates energy that can be captured and turned into electricity. This is called hydroelectric power or hydropower. It is the most widely used form of renewable energy, accounting for 16 percent of global electricity consumption, and 3,427 terawatt-hours of electricity production in 2010, which continues the rapid rate of increase experienced between 2003 and 2009.

Hydropower is produced in 150 countries, with the Asia-Pacific region generated 32 percent of global hydropower in 2010. China is the largest hydroelectricity producer, with 721 terawatt-hours of production in 2010, representing around 17 percent of domestic electricity use. There are now three hydroelectricity plants larger than 10 GW: the Three Gorges Dam in China, Itaipu Dam in Brazil, and Guri Dam in Venezuela.

The cost of hydroelectricity is relatively low, making it a competitive source of renewable electricity. The average cost of electricity from a hydro plant larger than 10 megawatts is 3 to 5 U.S. cents per kilowatt-hour. Hydro is also a flexible source of electricity since plants can be ramped up and down very quickly to adapt to changing energy demands. However, damming interrupts the flow of rivers and can harm local ecosystems, and building large dams and reservoirs often involves displacing people and wildlife and requires significant amounts of carbon-intensive cement. Once a hydroelectric complex is constructed, the project produces no direct waste, and has a considerably lower output level of the greenhouse gas carbon dioxide (CO2) than fossil fuel powered energy plants.continue @ ugreen.me

Water Power Hold Huge Potential

Through the results of two nationwide resource assessments, the US Department of Energy has found that harnessing the power generated by waves and tidal currents could  potentially provide 15% of the country’s electricity by 2030.

This new report is the most thorough analysis undertaken to date to determine the viability of America’s ocean energy. The DOE’s Office of Energy Efficiency believes that water power, which includes conventional hydropower and wave, tidal, and other water power resources, can further contribute to the country’s efforts to diversify its renewable energy portfolio.

Equally important is the potential for new industries and new jobs to emerge as a result of the reports’ positive findings.

Not surprisingly, the reports highlighted the West Coast including Alaska and Hawaii as the area with the highest potential for wave energy development, although the East Coast showed promise as well. Both coasts showed strong tidal energy production potential.

While the DOE estimates that wave and tidal energy could conceivably generate a third of the 4,000 terawatt hours (TWh) of electricity the United States consumes each year, not all of the resources can be realistically developed.

But the assessment did find that the country’s renewable hydropower resources can be expanded. Currently, 6% of the United State’s electricity comes from hydropower.

 
Read>>>>>

Every continent on the planet is surrounded by a cleaner, safer, more efficient answer to our energy needs. The power in ocean waves. Ocean Power Technologies (OPT) is a leading renewable energy company specializing in cost-effective, advanced, and environmentally sound offshore wave power technology. The electrical power generated by OPT's technology is key to meeting the energy needs of utilities, independent power producers and the public sector.

OPT's PowerBuoy® system extracts the natural energy in ocean waves, and is based on the integration of patented technologies in hydrodynamics, electronics, energy conversion and computer control systems. The PowerBuoy is a “smart” system capable of responding to differing wave conditions.

The result is a leading edge, ocean-tested, proprietary system which generates reliable, clean, and environmentally-beneficial electricity.

OPT's PowerBuoy® wave generation system uses a "smart," ocean-going buoy to capture and convert wave energy into low-cost, clean electricity.

The rising and falling of the waves off shore causes the buoy to move freely up and down. The resultant mechanical stroking is converted via a sophisticated power take-off to drive an electrical generator. The generated power is transmitted ashore via an underwater power cable.

A 10-Megawatt OPT power station would occupy only approximately 30 acres
(0.125 square kilometers) of ocean space.

Sensors on the PowerBuoy® continuously monitor the performance of the various subsystems and surrounding ocean environment. Data is transmitted to shore in real time. In the event of very large oncoming waves, the system automatically locks-up and ceases power production. When the wave heights return to normal, the system unlocks and recommences energy conversion and transmission of the electrical power ashore.

• Buoys are spaced to maximize energy capture.

• Rugged, simple steel construction.

• Utilizes conventional mooring systems.

• Simple installation using existing marine vessels and infrastructure.

• Scalable to large power stations (100+ MW)

How Hydropower Plants Work

Worldwide, hydro-power plants produce about 24 percent of the world's electricity and supply more than 1 billion people with power. The world's hydro-power plants output a combined total of 675,000 megawatts, the energy equivalent of 3.6 billion barrels of oil, according to the National Renewable Energy Laboratory. There are more than 2,000 hydro-power plants operating in the United States, making hydro-power the country's largest renewable energy source.

In this article, we'll take a look at how falling water creates energy and learn about the hydrologic cycle that creates the water flow essential for hydro-power. You will also get a glimpse at one unique application of hydro-power that may affect your daily life.

Read More @How Stuff Works.com 

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Energy Island

Nicola Tesla's inventions revolutionized the electricity industry and facilitated the fast paced growth of global industry. Since that time countless inventors have created amazing technologies that have completely changed the way we live. Today there are thousands of individuals and companies across the globe who are working hard to develop alternative energy solutions for future generations.

Innovative Hydropower

Innovative Hydropower Tested in Portland - Testing, Testing!

Once again, Portland is making itself a test bed for clean energy. The Portland Water Bureau has signed a Memorandum of Understanding with the mayor’s office, the Portland Development Commission, and  local hydropower innovator, Lucid Energy, to test in-pipe hydropower. The technology basically fits round turbines into large pipe to harvest excess head pressure and converts it into clean reliable energy. While testing will prove whether this technology will work on a system wide scale, Portland leaders are hopeful.

In the video below, Mayor Adam asks Administrator Shaff about his first, honest reaction: “Yeah, I don’t think so. But we’ve looked at it, and our engineers think, well sure, why not? That’s a possibility. Let’s see if we can do something and see if we can be the test bed that they’re looking for. We have large diameter pipe. We have 100 million gallons a day going through our pipes throughout the year, 34 billion gallons a year. If we can capture some energy from that water going through the pipes every day, 24 hours a day, I think that’s a great idea.”