Mechanical Water Use

Compiled by:
Jose Carrasco (aquasis/cewas, International Centre for Water Management Services), Andrea Pain (seecon international gmbh)
Adapted from:
BATES, L.; HUNT, S.; KHENNAS, S.; SASTRAWINATA, N. (2009)

Executive Summary

The force of water has been used for centuries to produce mechanical power. In remote villages and among low-income regions around the world, daily activities such as agro/food processing and water pumping are possible due to mechanical power. Today, mechanical power contributes to increase the efficiency and effectiveness of productive activities aiming to meet basic human needs such as water supply access, natural resource extraction and small-scale manufacturing. Mechanical power can be considered as a sustainable source of energy services for low-income people since it does not require high investment costs.
In Out

Precipitation, Freshwater

Freshwater, Energy

Introduction

While water resources are valued for human health and for sustaining food production, the energy contained in moving water such as rivers or tides can also be harnessed to do work through mechanical devices, or to create energy in small scale or large scale hydropower schemes. Globally, 1.4 billion people lack access to electricity, with an additional 1 billion having only intermittent access (UNDP 2012). As running water is a resource that is globally available and renewable, harnessing its power for mechanical uses can improve livelihoods and increase working productivity even in rural or developing areas where no local electricity source is available.

 BATES et al. (2009)

Relationship between energy sources and their impact on prosperity and development, as compared to their technical complexity. Source: BATES et al. (2009)

How Does it Work?

Regardless of the technology used to use water for mechanical power, the principle of mechanical water use is the same: that the kinetic energy contained in flowing water can be harnessed and converted into mechanical energy in order to do work. The amount of energy that can be harvested depends on both the quantity of water flowing, and the velocity (speed) at which it flows.

There are many devices that can be implemented to use water for mechanical purposes. Some of the most important technologies are summarised below:

Water Wheels

Adapted from TRYENGINEERING (2011)

 How Does it Work?  Regardless of the technology used to use water for mechanical power, the principle of mechanical water use is the same: that the kinetic energy contained in flowing water can be harnessed and converted into mechanical energy in order to do work. The amount of energy that can be harvested depends on both the quantity of water flowing, and the velocity (speed) at which it flows. There are many devices that can be implemented to use water for mechanical purposes. Some of the most important technologies are summarised below:  Water Wheels Adapted from TRYENGINEERING (2011) A watermill is a structure that uses a water wheel or turbine to drive a mechanical process. A watermill works by diverting water from a river or pond to a water wheel, usually along a channel or pipe. The water's force drives or pushes the blades of the wheel (or turbine), which then turns or rotates an axle that drives machinery that is attached to it to do work. This machinery performs a specific task, such as transporting water or milling flour. Waterwheels can either be horizontal or vertical with respect to water flow. Horizontal water wheels are simpler, but require high water velocities to work well. There are many types of water wheel. One type, called a noria, is pictured below, and is used to transport water from a running stream into a trough for local water supply.

“Noria” water wheel. Source: MACHINERY CORPORATION (2012) 

A water mill is a structure that uses a water wheel or turbine to drive a mechanical process. A water mill works by diverting water from a river or pond to a water wheel, usually along a channel or pipe. The water's force drives or pushes the blades of the wheel (or turbine), which then turns or rotates an axle that drives machinery that is attached to it to do work. This machinery performs a specific task, such as transporting water or milling flour. Waterwheels can either be horizontal or vertical with respect to water flow. Horizontal water wheels are simpler, but require high water velocities to work well. There are many types of water wheel. One type, called a noria (pictured right) is used to transport water from a running stream into a trough for local water supply.

Water Mills and Improved Water Mills

  SHRETHA & SHRESTHA (1999)

Scheme of an improved water mill used for cereal grinding in Nepal. Source: SHRETHA & SHRESTHA (1999) 

A water mill is a water wheel or turbine that is connected to a device that drives a mechanical process. Water mills can be used for such purposes as grinding flour or agricultural produce, cutting up materials such as pulp or timber, or metal shaping. Traditional water mills are made from a wheel or turbine with wooden blades that turn when water runs through. The turbine or wheel then turns a grinder shaft, which is connected to a grinding stone.

Recently, improved water mills have been designed which replace wooden blades with metal, cup-shaped blades. This modification has led to a doubling of efficiency and operational capacity by over 100%. Improved water mills have been successfully used as a cereal grinder, paddy huller, oil expeller, saw mill, as well as to produce electricity when coupled with an electric generator (GORKHALI 2010).

Tide Mills

Tide mills are made with a water wheel that is either placed across a tidal inlet or a section of an estuary made into a reservoir. Rising tides enter the mill pond through a one-way gate that closes automatically when the tide begins to fall. The stored water can then be used to turn a water wheel.

River Turbines

River turbines are turbines placed in a flowing river or canal, which are tethered to one side, and pump water to the shore. Output depends on river speed and depth.

Hydraulic Ram Pumps

Also known as “hydrams”, hydraulic rams are automatic pumping devices that use a large flow of falling water through a small head (low elevation) at an inlet in order to lift a small flow of water through a much higher head (high elevation) at an outlet, thus lifting the water (PRACTICAL ACTION 2002).

Applications of Mechanical Water Use

The dominant uses of mechanical power include water supply, agriculture, agro-processing, natural resource extraction, small-scale manufacturing, and lifting and crossing.

Water Supply

Having a clean and reliable source of drinking water is essential in improving the health of a community. In rural areas, water collection is often the responsibility of women, and consumes a great deal of time and energy. Mechanised water pumps can reduce the time and physical strain of water collection for women, allowing them to focus more on other activities, such as caring for children or taking care of their own health.

Service

Typical technology

Mechanical power alternative

Drinking, irrigation, livestock watering

Container (bucket) for lifting / carrying water

Hydraulic ram, water wheel, river turbine

Applicability of mechanical power at point of use. Source: BATES et al. (2009)

Agro-Processing

Post-harvest activity can be critical in helping farmers increase their income. For activities like milling, pressing, cutting, and shredding, Improved water mills can have an 80–90% increase in power use and efficiency compared to a traditional water mill. They can also have multiple uses such as for both agro-processing and power generation, which can increase the load of the mill and make such installations more sustainable.

Service

Typical technology

Mechanical power alternatives

Milling, pressing

Hand ground, flail

Water mill

Cutting, shredding

Knife

Water-powered saw mills

Applicability of mechanical power at point of use. Source: BATES et al. (2009)

Natural Resource Extraction

Artisanal and small-scale mining may be the only livelihood opportunity for some people, or may be their source of income during the agricultural off-season. There are many technologies that can reduce the effort needed for mining mentioned below.

Service

Typical technology

Mechanical power alternative

Minerals

Washing

Hand washed

Water powered water jet

Grading

Hand screen

Water powered shaker

Timber

Sawing

Hand saw

Powered saw (sawmill, chainsaw)

Applicability of mechanical power at point of use. Source: BATES et al. (2009)

Small-Scale Manufacturing

Mechanical power technologies allow micro-enterprises to produce goods consistently at the same quality and at a faster production rate. This, in turn, will directly affect their income for the same time spent on labour.

Services

Typical technology

Mechanical power alternative

Wood working, carpentry

Hand saw

Saw mill

Applicability of mechanical power at point of use. Source: BATES et al. (2009)

Lifting

Water can also be used for transport purposes. In countries such as Switzerland and France, water has historically been used for powering cable cars, using natural gradients and counter weights to drive cars up and down hills. These technologies are still in use today, but many have been replaced with designs that are powered by engines (DE DECKER 2009).

How to Optimise?

Mechanical water use is a non-consumptive water use. Therefore, there are possibilities to link mechanical water use to other uses, such as irrigation in agriculture. This can reduce the investment costs for individual users, thus expanding the possibilities for income generation and development.

Water for Energy and the Millennium Development Goals

Mechanical uses of water have many positive development impacts, which can be regarded for each of the Millennium Development Goals:

Goal

Impact

Goal 1: Eradication extreme poverty and hunger

  • Growing more food and accessing sufficient water can improve food security.
  • Pumping water to irrigate crops can prolong the growing season and reduce vulnerability to drought (see Optimisation in Agriculture).
  • Increased quantity, quality, and uniformity of manufactured goods/produce increases income for the producer.

Goal 2: Achieve universal primary education

  • Reduced burden on children to help with physical tasks (e.g.. fetching water) so they can attend school (see Human Powered Distribution).
  • Better nutrition for children reduces sick days.
  • Additional income may allow parents to pay for school fees.

Goal 3: Promote gender equality and empower women

Goal 4: Reduce child mortality

Goal 5: Improve maternal health

  • Mechanisation of physical tasks reduces work strain on pregnant women.
  • Better food security during pregnancy reduces anaemia in women and low birth weight in babies (see Water Sanitation and Health).

Goal 6: Combat HIV/AIDS, malaria, and other diseases

Goal 7: Ensure environmental sustainability

  • Using water for energy reduces pressure on other sources (firewood from forests).
  • Slash-and-burn agriculture may decrease if farming efficiency and productivity is improved.

Goal 8: Develop a Global Partnership for Development

  • Aggregating demand across multiple social and income-generating needs within the community lowers unit costs for each partner and generates income for all (see Water Sanitation and Economy).

For more information on the Millennium Development Goals with regard to water and sanitation, see Access to Water and Sanitation, and Water Sanitation and Development.

Cost

  • Because of the large increases in working productivity and efficiency, mechanical water use is considered to be one of the most cost-effective ways of supporting poor people.
  • Mechanical devices are generally low-investment. However, the upfront capital needed is a key barrier in rural areas where investment capital is scarce. Microfinance institutions have been successful in overcoming this barrier.
  • When investment capital is available, mechanical water use can nearly double revenue due to increased productivity.
  • When multiple users are involved (for example when coupling mechanical water use with irrigation), investment costs are decreased for all users, and there may be greater opportunities for income generation.

Applicability

Mechanical water use relies on flowing water. Technologies can be implemented wherever there is enough force by moving water to drive the device. This force is dependent on the quantity of water, as well as the velocity (speed) at which it is flowing. Therefore, mechanical water use is most applicable where there is a steady source of flowing water (i.e. rivers, streams) to drive the machinery.

Advantages

  • Reduced drudgery, increased work rate
  • Increased work efficiency and output productivity
  • Lower time and production costs
  • Increased range of improved products possible
  • Non-consumptive use of water allows coupling of mechanical water use with other uses
  • Can be available even in rural or underdeveloped areas

Disadvantages

  • Must have steady source of running water
  • Must have steady source of running water
  • Powerful machinery may cause injuries
  • Natural resources may become degraded due to increased agricultural activity and natural resource extraction

References Library

BATES, L.; HUNT, S.; KHENNAS, S.; SASTRAWINATA, N. (2009): Expanding Energy Access in Developing Countries: The Role of Mechanical Power. Warwickshire: Practical Action Publishing Ltd. URL [Accessed: 28.03.2012].

DE DECKER, K. (2009): Water powered cable trains. Barcelona: Low-tech Magazine. URL [Accessed: 04.09.2012].

GORKHALI, H.G. (2010): Improving Livelihood of Rural Mountain People through Promotion of Pico-Hydro Technologies. A Case of Nepal. Kathmandu: The Centre for Rural Technology, Nepal.

MACHINERY CORPORATION (Editor) (2012): The History of the Noria. Tulsa, OK: Machinery Corporation. URL [Accessed: 28.03.2012].

PRACTICAL ACTION (Editor) (2002): Hydraulic Ram Pumps. Bourton on Dunsmore: Practical Action. URL [Accessed: 04.10.2012].

SHRESTHA, L.K.; SHRESTHA G.R. (2006): Opening Productive Avenues for Rural Women through Improved Water Mills in Nepal. In: Energia News 9, 8-10. URL [Accessed: 28.03.2012].

TRYENGINEERING (Editor) (2011): Working with Watermills. Piscataway, NJ: Try Engineering Association. URL [Accessed: 27.08.2012].

UNDP (Editor) (2012): Universal access to modern energy for the poor. New York: United Nations Development Program (UNDP). URL [Accessed: 28.08.2012].

Further Readings Library

Reference icon

HASSAN, F. (2011): Historical Transformations of Water Management . A Punctuated, Co-evolutionary Theory. (= Water History for our Times, 2). Paris: United Nations Educational, Scientific and Cultural Organization (UNESCO). URL [Accessed: 28.03.2012].

This document provides a detailed account of the history of water management. It covers diverse topics related to the history of technological innovations in water management from irrigation to industrial water use, as well as changing attitudes, policies, and ethical considerations regarding water use throughout history.


Reference icon

HILL, P. (2009): How to Develop a Micro Hydro Scheme. West Yorks, U.K.: Alternative Technology Centre. URL [Accessed: 28.03.2012].

This guide provides a concise technical guide to build a micro hydro system, with sufficient technological knowledge. Aspects such as capacity, equipment and permissions are discussed in this document. This report provides a special section on water wheels.


Reference icon

IT POWER (Editor) (2011): Financing Watermill Upgrades, The Business Case for Banking Support. London: United Kingdom Department for International Development (DFID). URL [Accessed: 28.03.2012].

This summary report presents the business case for supporting the upgrading of traditional watermills with improved technology. The report is directed at the banking community with the aim of encouraging rural and agricultural banks to offer appropriate finance for new projects. The report provides an overview of the technical, financial, social and market characteristics of watermill upgrades.


Reference icon

PEARSON, W. (1996): Water Power in Dry Continent: The Transfer of Watermill Technology from Britain to Australia in the Nineteenth Century. In: Australasian Historical Archaeology 14, 46-62. URL [Accessed: 28.03.2012].

This report presents the results of a study aiming to construct a model for the transfer and adaptation of watermills from Britain to Australia in the nineteenth century. It provides a model and a number of factors to consider when a country decides to import a technology from another country.


Reference icon

ROBERTSON, A. (2005): Water Power Sawmills in New Foundland. St John’s: Alexander Robertson. URL [Accessed: 28.03.2012].

This book is a historical account of the use of waterwheels in Newfoundland, Canada. It provides descriptions as well as technical drawings of the many types of waterwheels that were used in this region.


Case Studies Library

Reference icon

KITIO, V. (2011): Noria. In the End of Famine in Africa. Mbouda, Cameroon: African Centre for Renewable Energy & Sustainable Technology. URL [Accessed: 28.03.2012].

In Medinet El Faiyum, Egypt, the installation of a noria has been successful in increasing food security despite the lack of rainfall in the region. Farmers are able to harvest three times a year despite the fact that the region receives only three days of rain a year. This is thanks to waterwheels that were introduced several centuries ago by Ptolemic engineers. They are still working today side by side with electric water pumps to grow olives, vegetables, fruits, nuts, sugar cane, rice, and wheat.


Reference icon

SHRESTHA, L.K.; SHRESTHA G.R. (2006): Opening Productive Avenues for Rural Women through Improved Water Mills in Nepal. In: Energia News 9, 8-10. URL [Accessed: 28.03.2012].

This short case study focus on the technical aspects and overall performance improved water mills in Nepal. These improved water mills have brought an increase in grinding capacity as well as direct benefits to woman (involved in new economic activities).


Awareness Raising Material Library

Reference icon

CENTRE FOR RURAL TECHNOLOGY (Editor) (2007): Ashden Awards Case Study. Kathmandu, Nepal: Centre for Rural Technology Nepal. URL [Accessed: 30.03.2012].

This case study presents a resume of the programme to upgrade traditional water mills in remote villages in Nepal. The technological aspects as well as cost and environmental and social benefits are included in this document.


Reference icon

FRANGI, B. (2010): Noria and Small Scale Irrigation: Changing the Face of Upland Farming. Lao PDR: Care International in Lao Peoples Democratic Republic. URL [Accessed: 28.03.2012].

This factsheet provides information on a rural development Lao PDR. Whereas the overall goal of the project is to be a trial for the Noria (water wheel) technology, the project seeks to increase rice production and production efficiency in the target area.


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INDIAN INSTITUTE OF TECHNOLOGY (Editor) (2008): Water Mill. Roorkee, India: Indian Institute of Technology Roorkee Alternate Hydro Energy Centre. URL [Accessed: 28.03.2012].

This paper describes the design and implementation of a multipurpose power unit at existing water mills from Kashmir to Arunachal Pradesh in India. These new multipurpose systems aims to increased milling capacity, oil expelling, rice hulling, spice-hulling, processing of dairy and food products, workshop machines, wood working, metal working, textiles carding, and commercial cooking.


Training Material Library

Reference icon

SAMMAN, M. (2005): Rediscovering the Waterwheel “Noria Al-Muhammadiyya”. New York: American Society of Mechanical Engineers. URL [Accessed: 30.03.2012].

This presentation includes an overview about water-driven waterwheels and is illustrated with photos, draws and sketches about the different water devices.


Important Weblinks

http://www.youtube.com/ [Accessed: 30.03.2012]

This video shows the improved water mills project in Nepal, developed by the Centre of Rural Technology. The documentary describes how the project was initiated and all the different actors involved (e.g. manufactures, service centres, farmers) in the improved water mills.

http://www.noriaproject.com/ [Accessed: 30.03.2012]

This is a website that host information on the Noria project, that aims to meet local people around the world and visit the project on water subjects in order to observe and report the importance for the economy of this vital resource.

http://www.aepc.gov.np/ [Accessed: 30.03.2012]

This is an official website from the government of Nepal with the objective of developing and promoting renewable energy technologies in the country. There is a special section that contains documents, description, and photos on improved water mills.