Small hydro
Encyclopedia
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. In contrast many hydroelectric projects are of enormous size, such as the generating plant at the Hoover Dam
Hoover Dam
Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President...
of 2,074 megawatts or the vast multiple projects of the Tennessee Valley Authority
Tennessee Valley Authority
The Tennessee Valley Authority is a federally owned corporation in the United States created by congressional charter in May 1933 to provide navigation, flood control, electricity generation, fertilizer manufacturing, and economic development in the Tennessee Valley, a region particularly affected...
.
Small hydro can be further subdivided into mini hydro, usually defined as less than 1,000 kW, and micro hydro which is less than 100 kW. Micro hydro
Micro hydro
Micro hydro is a term used for hydroelectric power installations that typically produce up to 100 kW of electricity. These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks....
is usually the application of hydroelectric power sized for small communities, single families or small enterprise.
Small hydro plants may be connected to conventional electrical distribution networks as a source of low-cost renewable energy. Alternatively, small hydro projects may be built in isolated areas that would be uneconomic to serve from a network, or in areas where there is no national electrical distribution network. Since small hydro projects usually have minimal reservoirs and civil construction work, they are seen as having a relatively low environmental impact compared to large hydro. This decreased environmental impact depends strongly on the balance between stream flow and power production. One tool that helps evaluate this issue is the Flow Duration Curve or FDC. The FDC is a Pareto curve
Pareto principle
The Pareto principle states that, for many events, roughly 80% of the effects come from 20% of the causes.Business-management consultant Joseph M...
of a stream's daily flow rate vs. frequency. Reductions of diversion help the river's ecosystem, but reduce the hydro system's Return on Investment
Return on investment
Return on investment is one way of considering profits in relation to capital invested. Return on assets , return on net assets , return on capital and return on invested capital are similar measures with variations on how “investment” is defined.Marketing not only influences net profits but also...
(ROI). The hydro system designer and site developer must strike a balance to maintain both the health of the stream and the economics.
Growth
During 2008 small hydro installations grew by 28% over year 2005 to raise the total world small hydro capacity to 85 gigawatts. Over 70% of this was in ChinaChina
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
(with 65 GW), followed by Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
(3.5 GW), the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
(3 GW) and India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
(2 GW). China plans to electrify a further 10,000 villages by 2010 under their China Village Electrification Program
China Village Electrification Program
The China Village Electrification Program is a scheme to provide renewable electricity to 3.5 million households in 10,000 villages by 2010. This is to be followed by full rural electrification using renewable energy by 2015....
using renewable energy
Renewable energy
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable . About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from...
, including further investments in small hydro and photovoltaics
Photovoltaics
Photovoltaics is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material...
.
Generation
Hydroelectric power is the generation of electric power from the movement of water. A hydroelectric facility requires a dependable flow of water and a reasonable height of fall of water, called the head. In a typical installation, water is fed from a reservoir through a channel or pipe into a turbine. The pressure of the flowing water on the turbine blades causes the shaft to rotate. The rotating shaft is connected to an electrical generatorElectrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
which converts the motion of the shaft into electrical energy.
Small hydro is often developed using existing dams or through development of new dams whose primary purpose is river and lake water-level control, or irrigation. Occasionally old, abandoned hydro sites may be purchased and re-developed, sometimes salvaging substantial parts of the installation such as penstocks and turbines, or sometimes just re-using the water rights associated with an abandoned site. Either of these cost saving advantages can make the ROI for a small hydro site well worth the use of existing site infrastructure & water rights.
Project design
Many companies offer standardized turbine generator packages in the approximate size range of 200 kW to 10 MW. These "water to wire" packages simplify the planning and development of the site since one vendor looks after most of the equipment supply. Since non-recurring engineering costs are minimized and development cost is spread over multiple units, the cost of such systems is improved. While synchronous generators capable of isolated plant operation are often used, small hydro plants connected to an electrical grid system can use economical induction generatorInduction generator
An induction generator or asynchronous generator is a type of AC electrical generator that uses the principles of induction motors to produce power. Induction generators operate by mechanically turning their rotor in generator mode, giving negative slip...
s to further reduce installation cost and simplify control and operation.
Micro-hydro plants may use purpose-designed turbines or use industrial centrifugal pumps, connected in reverse to act as turbines. While these machines rarely have optimum hydraulic characteristics when operated as turbines, their low purchase cost makes them attractive for micro-hydro class installations.
Regulation of small hydro generating units may require diversion of water around the turbine, since the project may have no reservoir to store unused water. For micro-hydro schemes feeding only a few loads, a resistor bank may be used to dissipate electrical energy as heat during periods of low demand. In a sense this energy is wasted but the incremental fuel cost is negligible so there is little economic loss.
Other small hydro schemes may use tidal energy or propeller-type turbines immersed in flowing water to extract energy. Tidal schemes may require water storage or electrical energy storage to level out the intermittent (although exactly predictable) flow of power.
Since small hydro projects usually have minimal environmental and licensing procedures, and since the equipment is usually in serial production, standardized and simplified, and since the civil works construction is also small, small hydro projects may be developed very rapidly. The physically small size of equipment makes it easier to transport to remote areas without good road or rail access.
Micro-hydro installations can also provide multiple uses. For instance, micro-hydro projects in rural Asia have incorporated agro-processing facilities such as rice mills - alongside standard electrification - into the project design.
Small scale DIY hydroplants
With a growing DIY-community and an increasing interest in environmentally friendly "green energy", some hobbyHobby
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...
ists have endeavored to build their own hydroeletric plants from old water mills, or from kits or from scratch. Usually, the DIY-community uses decayed/abandoned water mills to mount a waterwheel and other electrical components. This approach has also been popularised in TV-series as It's Not Easy Being Green
It's Not Easy Being Green
It's Not Easy Being Green is a television series on BBC Two starring Dick Strawbridge and focusing on how to live an environmentally friendly, low impact life...
. These are usually smaller turbines of ~5 kW or less. Through the internet, the community is now able to obtain plans to construct DIY-water turbines. and there is a growing trend toward building them for domestic requirements. The DIY-hydroelectric plants are now being used both in developed countries and in developing countries, to power residences and small businesses.
Sample list of small installations worldwide
Asia- Bario Asal & Arur Layun Micro-Hydro Community Project, Kelabit HighlandsKelabit HighlandsThe Kelabit Highlands are a mountain range located in the northernmost part of Sarawak, on the island of Borneo. The highest mountains in this range are Mount Murud at 2,423 m , Bukit Batu Buli at 2,082 m , and Bukit Batu Lawi at 2,046 m .In the Kelabit Highlands, there are 14...
, SarawakSarawakSarawak is one of two Malaysian states on the island of Borneo. Known as Bumi Kenyalang , Sarawak is situated on the north-west of the island. It is the largest state in Malaysia followed by Sabah, the second largest state located to the North- East.The administrative capital is Kuching, which...
, Malaysia.
Europe
- St Catherine's, a National TrustNational Trust for Places of Historic Interest or Natural BeautyThe National Trust for Places of Historic Interest or Natural Beauty, usually known as the National Trust, is a conservation organisation in England, Wales and Northern Ireland...
site near Windermere, WestmorlandWestmorlandWestmorland is an area of North West England and one of the 39 historic counties of England. It formed an administrative county from 1889 to 1974, after which the entirety of the county was absorbed into the new county of Cumbria.-Early history:...
, United KingdomUnited KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. - Green Valleys Project, Brecon Beacons National Park, WalesWalesWales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
, United KingdomUnited KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. Joint winner of £300K in Big Green Challenge 2009.
North America
- Ames Hydroelectric Generating PlantAmes Hydroelectric Generating PlantThe Ames Hydroelectric Generating Plant, located near Ophir, Colorado, was the world's first commercial system to produce and transmit alternating current electricity. It is now on the List of IEEE Milestones....
, ColoradoColoradoColorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
. On the List of IEEE Milestones - Snoqualmie FallsSnoqualmie FallsSnoqualmie Falls is a 268 ft waterfall on the Snoqualmie River between Snoqualmie and Fall City, Washington, USA. It is one of Washington's most popular scenic attractions, but is perhaps best known internationally for its appearance in the cult television series Twin Peaks...
, Washington, United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
. - Childs-Irving Hydroelectric FacilitiesChilds-Irving Hydroelectric Facilities-History:The water rights of Fossil Creek, located between Pine/Strawberry and Camp Verde, Arizona, were purchased in 1900 by rancher Lew Turner. His goal was to generate hydroelectric power for sale to mining communities in the Bradshaw Mountains and Black Hills in Yavapai County, such as Jerome,...
, ArizonaArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
. - Buckeye, ArizonaBuckeye, ArizonaBuckeye is a town in Maricopa County, Arizona, United States and is the westernmost suburb in the Phoenix metropolitan area. The population of the town as of Census 2010 was 50,876, a 678% increase from the 2000 population of 6,537.-Geography:...
, United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
See also
- Micro hydroMicro hydroMicro hydro is a term used for hydroelectric power installations that typically produce up to 100 kW of electricity. These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks....
- Pico hydroPico hydroPico hydro is a term used for hydroelectric power generation of under 5 kW. It is useful in small, remote communities that require only a small amount of electricity - for example, to power one or two fluorescent light bulbs and a TV or radio in 50 or so homes. Even smaller turbines of...
- Electricity generationElectricity generationElectricity generation is the process of generating electric energy from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...
- Low head hydro powerLow head hydro powerLow head hydro power applications use river current or tidal flows of 20 meters or less to produce energy. These applications do not need to dam or retain water to create hydraulic head; the head is only a few metres...
- Hydro Power