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| = Overview<br/> = | | = Overview<br/> = |
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− | A '''micro hydro power (MHP)''' plant is a type of hydro electric power scheme that produces up to 100 KW of electricity using a flowing steam or a water flow. The electricity from such systems is used to power up isolated homes or communities and is sometimes connected to the main grid.<ref name="Wikipedia: http://en.wikipedia.org/wiki/Micro_hydro">Wikipedia: http://en.wikipedia.org/wiki/Micro_hydro</ref><br/>
| + | <u>Classification of hydro power can be summarized as follows<ref name="Micro hydropower: http://www.microhydropower.net/basics/intro.php">Micro hydropower: http://www.microhydropower.net/basics/intro.php</ref><ref name="Practical Action: https://practicalaction.org/docs/technical_information_service/micro_hydro_power.pdf">Practical Action: https://practicalaction.org/docs/technical_information_service/micro_hydro_power.pdf</ref>:</u> |
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− | <u>Classification of micro hydropower can be summarized as follows<ref name="Micro hydropower: http://www.microhydropower.net/basics/intro.php">Micro hydropower: http://www.microhydropower.net/basics/intro.php</ref><ref name="Practical Action: https://practicalaction.org/docs/technical_information_service/micro_hydro_power.pdf">Practical Action: https://practicalaction.org/docs/technical_information_service/micro_hydro_power.pdf</ref>:</u> | + | |
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| {| cellspacing="1" cellpadding="5" border="1" style="width: 100%" | | {| cellspacing="1" cellpadding="5" border="1" style="width: 100%" |
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− | | style="background-color: rgb(153, 153, 153); width: 100px" | '''Type '''<br/> | + | | style="background-color: rgb(153, 153, 153); width: 121px" | '''Type '''<br/> |
− | | style="background-color: rgb(153, 153, 153); width: 100px" | '''Description'''<br/> | + | | style="background-color: rgb(153, 153, 153); width: 619px" | '''Description'''<br/> |
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− | | style="width: 100px; text-align: right; background-color: rgb(204, 204, 204)" | Large Hydro<br/> | + | | style="width: 121px; text-align: right; background-color: rgb(204, 204, 204)" | Large Hydro<br/> |
− | | style="width: 640px" | All installations with an installed capacity of more than 1000 kW (according to some definitions more than 10,000 kW) | + | | style="width: 619px" | All installations with an installed capacity of more than 1000 kW (according to some definitions '''more than 10,000 kW''') |
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− | | style="width: 100px; text-align: right; background-color: rgb(204, 204, 204)" | Medium Hydro<br/> | + | | style="width: 121px; text-align: right; background-color: rgb(204, 204, 204)" | Medium Hydro<br/> |
− | | style="width: 640px" | 15 - 100 MW - usually feeding a grid | + | | style="width: 619px" | '''15 - 100 MW '''- usually feeding a grid |
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− | | style="width: 100px; text-align: right; background-color: rgb(204, 204, 204)" | Small Hydro<br/> | + | | style="width: 121px; text-align: right; background-color: rgb(204, 204, 204)" | Small Hydro<br/> |
− | | style="width: 640px" | Installations of 1-15 MW usually feeding into the grid | + | | style="width: 619px" | Installations of '''1-15 MW''' usually feeding into the grid |
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− | | style="width: 100px; text-align: right; background-color: rgb(204, 204, 204)" | Mini Hydro<br/> | + | | style="width: 121px; text-align: right; background-color: rgb(204, 204, 204)" | Mini Hydro<br/> |
− | | style="width: 640px" | Capacity '''between 100 - 500 kW''', either as stand-alone schemes or more often feeding into the grid | + | | style="width: 619px" | Capacity '''between 100 - 500 kW''', either as stand-alone schemes or more often feeding into the grid |
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− | | style="width: 100px; text-align: right; background-color: rgb(204, 204, 204)" | Micro Hydro<br/> | + | | style="width: 121px; text-align: right; background-color: rgb(204, 204, 204)" | Micro Hydro<br/> |
− | | style="width: 640px" | Installations with power output of '''5 - 100 kW''', usually provided power for small community or rural industry in remote areas away from the grid | + | | style="width: 619px; background-color: rgb(255, 255, 204)" | Installations with power output of '''5 - 100 kW''', usually provided power for small community or rural industry in remote areas away from the grid |
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− | | style="width: 100px; text-align: right; background-color: rgb(204, 204, 204)" | Pico Hydro<br/> | + | | style="width: 121px; text-align: right; background-color: rgb(204, 204, 204)" | Pico Hydro<br/> |
− | | style="width: 640px" | From a few hundred watts '''up to 5 kW''' | + | | style="width: 619px" | From a few hundred watts '''up to 5 kW''' |
| |} | | |} |
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− | <br/> | + | |
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| + | A '''micro hydro power (MHP)''' plant is a type of hydro electric power scheme that produces up to 100 KW of electricity using a flowing steam or a water flow. The electricity from such systems is used to power up isolated homes or communities and is sometimes connected to the main [[Portal:Grid|grid]].<ref name="Wikipedia: http://en.wikipedia.org/wiki/Micro_hydro">Wikipedia: http://en.wikipedia.org/wiki/Micro_hydro</ref> |
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| Micro hydro systems are generally used in developing countries to provide electricity to isolated communities or rural villages where electricity grid is not available. Feeding back into the national grid when electricity production is in surplus is also evident in some cases. The micro hydro scheme design can be approached as per household basis or at the village level often involving local materials and labor.<ref name="European small hydropower association: http://www.esha.be/fileadmin/esha_files/documents/publications/publications/Brochure_SHP_for_Developing_Countries.pdf">European small hydropower association: http://www.esha.be/fileadmin/esha_files/documents/publications/publications/Brochure_SHP_for_Developing_Countries.pdf</ref> | | Micro hydro systems are generally used in developing countries to provide electricity to isolated communities or rural villages where electricity grid is not available. Feeding back into the national grid when electricity production is in surplus is also evident in some cases. The micro hydro scheme design can be approached as per household basis or at the village level often involving local materials and labor.<ref name="European small hydropower association: http://www.esha.be/fileadmin/esha_files/documents/publications/publications/Brochure_SHP_for_Developing_Countries.pdf">European small hydropower association: http://www.esha.be/fileadmin/esha_files/documents/publications/publications/Brochure_SHP_for_Developing_Countries.pdf</ref> |
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| *'''Suitable site characteristics required: '''The system is very site selective and especially when you need to take full advantage of the electrical potential of small streams. Some factors that should be considered in such a case include, distance from the power source to the location where energy is required, stream size (including flow rate, output and drop), and a balance of system components — inverter, batteries, controller, transmission line and pipelines. | | *'''Suitable site characteristics required: '''The system is very site selective and especially when you need to take full advantage of the electrical potential of small streams. Some factors that should be considered in such a case include, distance from the power source to the location where energy is required, stream size (including flow rate, output and drop), and a balance of system components — inverter, batteries, controller, transmission line and pipelines. |
| * | | * |
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| '''Energy expansion not possible:'''The size and flow of small streams limits the possibility of future expansion as the power demand increases. | | '''Energy expansion not possible:'''The size and flow of small streams limits the possibility of future expansion as the power demand increases. |
| * | | * |
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| '''Low-power in the summer months:''' Since streams will reduce their flow rates depending on the season, summer months are likely to have less flow leading to less power output. However advanced planning and research can ensure adequate energy requirements are met. | | '''Low-power in the summer months:''' Since streams will reduce their flow rates depending on the season, summer months are likely to have less flow leading to less power output. However advanced planning and research can ensure adequate energy requirements are met. |
| *'''Environmental impact:''' There is a low ecological impact from small-scale hydro systems, however the low-level environmental effects must be taken into consideration before construction begins. Stream water will be diverted away from a portion of the stream, and proper caution must be exercised to ensure there will be no damaging impact on the local ecology or civil infrastructure.<br/> | | *'''Environmental impact:''' There is a low ecological impact from small-scale hydro systems, however the low-level environmental effects must be taken into consideration before construction begins. Stream water will be diverted away from a portion of the stream, and proper caution must be exercised to ensure there will be no damaging impact on the local ecology or civil infrastructure.<br/> |
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| = Application: Use of Micro Hydro Power Plants<br/> = | | = Application: Use of Micro Hydro Power Plants<br/> = |
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| *Public Funding which should be used in the support of primary investment in non local components of mini-grids and infrastructure, while costs for local material, labor and all operation and maintenance costs should be covered by a local business model.<br/> | | *Public Funding which should be used in the support of primary investment in non local components of mini-grids and infrastructure, while costs for local material, labor and all operation and maintenance costs should be covered by a local business model.<br/> |
| *Imposing a levy on on-grid electrification prices for large consumers can as well be a form of increasing the availability of government funds since extra funds that are collected can be used for rural electrification. | | *Imposing a levy on on-grid electrification prices for large consumers can as well be a form of increasing the availability of government funds since extra funds that are collected can be used for rural electrification. |
− | *Bringing down costs is another option of making MHP projects more attractive for private investors. One good practice could be to set up the MHP model with an integrated ownership model, this means that; : a private investor is responsible for the upfront-capital, the set up and the technical Operation and Maintenance of the MHP plant; the community is, however, involved in collecting payments, dealing with payment delay, theft and in organizing community contributions. A community committee responsible for tariff setting can also help to ensure that a tariff system is set up which allows for enough income to cover costs, maintenance and repairs, to offer reliable revenues for the private investor and to ensure that tariffs are still within the local range of willingness and ability to pay. If MHP systems are grid-connected, a reliable and attractive feed-in-tariff is the best option to ensure the long-term financial viability of a MHP system.<br/> | + | *Bringing down costs is another option of making MHP projects more attractive for private investors. One good practice could be to set up the MHP model with an integrated ownership model, this means that a private investor is responsible for the upfront-capital, the set up and the technical Operation and Maintenance of the MHP plant; the community is, however, involved in collecting payments, dealing with payment delay, theft and in organizing community contributions. A community committee responsible for tariff setting can also help to ensure that a tariff system is set up which allows for enough income to cover costs, maintenance and repairs, to offer reliable revenues for the private investor and to ensure that tariffs are still within the local range of willingness and ability to pay. If MHP systems are grid-connected, a reliable and attractive feed-in-tariff is the best option to ensure the long-term financial viability of a MHP system.<br/> |
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− | | style="text-align: center; background-color: rgb(204, 204, 204)" colspan="2" | Generation based (kWh)<br/> | + | | colspan="2" style="text-align: center; background-color: rgb(204, 204, 204)" | Generation based (kWh)<br/> |
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− | | style="background-color: rgb(204, 204, 204)" rowspan="2" | <p style="text-align: center"></p><p style="text-align: center"></p><p style="text-align: center">Supply</p><p style="text-align: center">Side<br/></p> | + | | rowspan="2" style="background-color: rgb(204, 204, 204)" | <p style="text-align: center"></p><p style="text-align: center"></p><p style="text-align: center">Supply</p><p style="text-align: center">Side<br/></p> |
| | style="background-color: rgb(153, 204, 255)" | | | | style="background-color: rgb(153, 204, 255)" | |
| Feed-in tarrifs<br/> | | Feed-in tarrifs<br/> |
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| Fiscal measures | | Fiscal measures |
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− | | style="background-color: rgb(204, 204, 204)" rowspan="2" | <p style="text-align: center"></p><p style="text-align: center"></p><p style="text-align: center">Demand</p><p style="text-align: center">Side</p> | + | | rowspan="2" style="background-color: rgb(204, 204, 204)" | <p style="text-align: center"></p><p style="text-align: center"></p><p style="text-align: center">Demand</p><p style="text-align: center">Side</p> |
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| | style="background-color: rgb(153, 204, 255)" | | | | style="background-color: rgb(153, 204, 255)" | |
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| | <br/> | | | <br/> |
− | | style="text-align: center; background-color: rgb(204, 204, 204)" colspan="2" | Capacity based (kW)<br/> | + | | colspan="2" style="text-align: center; background-color: rgb(204, 204, 204)" | Capacity based (kW)<br/> |
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| |} | | |} |
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| <references /><br/> | | <references /><br/> |
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− | [[Category:Small-Hydro/Mini-Hydro]]
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− | [[Category:Micro_Hydro]]
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− | [[Category:Micro-Hydro/Pico-Hydro]]
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| [[Category:Hydro]] | | [[Category:Hydro]] |
| + | [[Category:Micro-Hydro/Pico-Hydro]] |
| + | [[Category:Micro_Hydro]] |
| + | [[Category:Small-Hydro/Mini-Hydro]] |
Micro hydro systems are generally used in developing countries to provide electricity to isolated communities or rural villages where electricity grid is not available. Feeding back into the national grid when electricity production is in surplus is also evident in some cases. The micro hydro scheme design can be approached as per household basis or at the village level often involving local materials and labor.[4]
Small scale hydropower stations like micro hydro schemes combine the advantages of hydropower with those of decentralized power generation, without the disadvantages of large scale installations.
As the above illustration shows power that is generated by MPH is a convenient source of electricity to fuel anything from workshop machines to domestic lighting as the power can also be supplied to villages via portable rechargeable batteries and thus there are no expensive connection costs. Batteries can as well be charged and used to provide the local community with power. For industrial use however, the turbine shaft can be used directly as mechanical power as opposed to converting it into electricity via generator or batteries. This is suitable for agro-processing activities such as milling, oil extraction and carpentry.[8]
Most micro-hydro systems are ‘run-of-river’ which means that they don’t need large dams to store water. However, they do need some water-management systems.[9]
The illustration above shows just how a micro-hydro system can be setup. For water diversion the river water level has to be raised by a barrier, the weir [1]. The water is diverted at the intake [2] and conveyed by the channel [3] along the landscape´s contour lines. The spillways [4] protect against damage from excessive water flow. Water is slowed down and collected in the fore bay [5], from where it enters into the penstock [7]; the pressure pipe conveys the water to the power house [6] where the power conversion turbine, mill or generating equipment is installed. The turbine is the core of a MHP, which is rotated by the moving water. Different types of turbines are used depending on the head and the flow of the site, the turbines are used to rotate a shaft which is then used to drive the generator.[9] The water is then discharged via the draft tube [8] or a tail race channel in case of cross flow or Pelton turbines.[10]
Due to the nature of the micro-hydro schemed to be remote; a local grid is constructed to distribute the electricity to the different users. The demand output must match the capacity of the generator otherwise the voltage and frequency can vary suddenly, which can result in the damage of certain electrical equipment. The power demand in an off-grid is often variable since people switch lights and machines on and off, so the supply from the micro-hydro system must be varied to keep close control. This can be done by varying the water flow, or by using an electronic load controller.[9]
The ideal geographical areas for exploiting small scale hydro schemes is where there are steep rivers flowing all year round. Islands with moist marine climates are also suitable. Low-head turbines have been developed for small-scale exploitation of rivers or irrigation canals where there is a small head but sufficient flow to provide adequate power.
To understand more about a suitable potential site, the hydrology of the site needs to be known and a site survey carried out so as to determine the actual flow and head data. Hydrological information is easily accessible from the metrological or irrigation department of the particular national government. Site surveys usually give a more detailed information of the site conditions to allow power calculation to be done and design work to begin. Flow data should however be collected over a period of one year where possible, this is to ascertain on the fluctuation in the river flow over the various seasons.[2]
The cost of investing in a MHP varies depending on the location and thus it is impossible to give accurate figures without knowing the specifics of the site.
Costs depend on the site conditions, availability and quality of equipment and construction and the mode of operation (off-grid or grid-connected). Local contributions can reduce these costs significantly.
MHP schemes require a high investment cost that are mostly acquired through public or donor funding. There is however a need to increase private sector involvement due to the high demand of public funds and the need to attain a long-term sustainability. Public and especially donor-based funding of entire MHP schemes should be complemented by creating conditions which make MHP projects attractive to private investors, including financial incentives and smart subsidies, and through this, the public funds can develop a leverage effect for private investment. However development of MHP depends on a certain degree of public support. With the current experience with off-grid MHP systems show that it is very difficult to develop schemes with less than at least 50% public funding.[14]
Most incentives are given on the supply side, based on the installed capacity of the scheme. On the other side, beside direct subsidies for the installation on the plant, some countries have fiscal measures that can facilitate for the purchase and import of certain equipment. Guarantees are however applied where a donor funded project promotes the financing of MHP through local banks. With this the most prominent generation based instrument to promote the use of renewable energies are feed-in tariffs.
The demand side however, quota obligations force utilities and/or the demand side to deploy a certain percentage of renewable energy technologies.