Water Mills of Nepal and More

Sustainable Options for the Mountains
Best Practices and Appropriate Technologies

Energy

We have provided a selection of promising examples of energy-related? technologies and practices that are specifically suited to mountain conditions.
? (Except for mini- and micro-hydropower, all the following technologies are taken from the “Manual for Rural Technology with Implications for Mountain Tourism”, prepared by the Centre for Rural Technology, Nepal, in collaboration with ICIMOD.)

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Boiler
Bijuli Dekchi
Cooking and/or Heating Stoves
Hydraulic Ram Pumps for Water Lifting
Improved Watermill
Increased Efficiency Water Mills
Mini- and Micro-hydropower
Peltric Sets
Small Scale Windmill
Solar Dryer for Agricultural Produce
Solar Lantern
Solar Photovoltaic Cells
Solar Passive Heating System

Increased Efficiency Water mills

It is estimated there are more than 100,000 traditional water mills in the Himalayan region. This ancient technology has been used since centuries in the hilly regions for grinding grain and other material or for rotating prayer wheels by the Buddhist monks.

Socially, they have been meeting points for villagers to get together.The water mills have been an integral part of people?s lives for the last many centuries in India?s northeast. The old, traditional devices are simple and mostly constructed locally.

Primarily, they consist of a vertical shaft with a runner at the bottom consisting of wooden blades. The flowing water from rivulets and streams is directed through open flumes at the runner, which then rotates the shaft. Two round millstones, hewn locally, are fitted at the top of the shaft to act as the grinding mill.

Constructed from locally available material such as wood, stones, bamboo, and reeds, these have efficiencies ranging from 10%- 15%. These mills they contribute greatly and directly to the quality of lives of the people living in these areas and they are mostly based on centuries-old technologies and techniques, which fail to fully utilize the benefits of waterpower.

The old machines used to cost the owner anything between 5000- 7000 rupees, and had to be replaced every 2- 3 years. The new machine costs just the same and has a life span of over 10 years. Thus, over its lifecycle, the new system ends up costing perhaps less than 30% of the old machines. Additionally, the owner is saved the trouble of replacing the machine every 2- 3 years. What is equally important is that these new machines can be serviced and repaired locally, in case the need arises. Maintenance procedures are simple
and are carried out with locally available resources and expertise.

Notably, due to the increased efficiency levels of these new machines, they can be effectively employed to produce electricity in addition to meeting the mechanical power needs of the people. One of these cross-flow water mills could produce anywhere between 3-5 kW of power, sufficient to meet the electricity needs of 25- 50 households. However, the cost of mills and accompanying machinery to produce power could be around rupees 150,000.

The social and economic benefits arising from having electricity in these villages would be self-evident 3/4 higher income levels, more time for recreation and study, and ability to undertake additional economic activities.

(Read the full article at http://www.teriin.org/news/terivsn/issue14/newsbrk.htm)

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Peltric Set Technology

The water of small streams and rivulets flowing near human settlements in the hills and mountains could be used to produce electricity that can be used for various end uses. The technology available for this purpose is called peltric set technology.

The peltric set is a miniaturised and local version of a pelton turbine that is used for electricity generation. It is the simplest form of combined turbine and generator. It is a small vertical shaft pelton turbine with a generator co-axially coupled with it. It generates electric power from a small quantity of water which is dropped from a large height to operate it.

A peltric set can be used to generate electricity for the following applications or end uses:
lighting households (1kW of electric power can light 10-12 rural households);
charging batteries (electricity can be stored in the battery in the day-time); or
operating radios, televisions, and VCRs.

Suitability for Mountain Use

Advantages
The peltric set technology can be used to provide electricity to rural and remote areas especially in the mountainous regions which suffer from low plant and low load factor, poor communication and no transportation.

It is a small individual micro hydro plant that can generate electricity sufficient for five to ten houses by the smallest unit available, e.g., 60 watts.

It is easy to install, operate, and maintain.It economises on transmission and distribution costs as the generating set can be located near user households.

Comparatively, the electric power generated by the peltric generating set has a low cost per unit. Actual cost, however, is dependen upon site specific conditions.

It can be afforded by an individual or a small group of interested households It is cheaper to install because:
-it only needs a small channel to convey the small quantity of water;
-it is easy to transport (weight 35kg);
-it uses HDPE pipes for penstock pipe (light, inexpensive and readily available);
-it can be installed within two days; and
-it can be operated using the break pressure tank of rural water supply and sprinkler system pipelines.

Environmental and Efficienc Implicatons

The electric power generated by a peltric set can be used for lighting, heating water, and cooking in low-watt cookers, reducing dependence on firewood for these purposes. Thus, it has positive environmental
implications. Its operation and end uses create no pollution at any point.

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Solar Photovoltaic (SPV) Cells

Solar photovoltaics is a technology that directly converts the radiation from the sun into electricity based on the a physical process that requires no moving parts. SPV is a proven technology. It is possible to generate about 120 watts of electricity from a 10sq.ft. area of SPV panel on a sunny day. It is reliable on different scale applications.

Solar photovoltaic technology has the following possible functions/applications:
Lighting (streets, residences, public places etc.)
Running or operating electro-mechanical equipment (radio and other systems, TV and video players, fans, pump sets to supply drinking or irrigation water etc.)
Supplying electrical power to operate poultry incubators, rice mills
telecommunications? equipment in remote areas, charge NiCd batteries for use in torches, radios and so on.

Suitability for Mountain Use?

Advantages
No fuel requirements. It does away with the often expensive and erratic supply of fuels.
It does not cost anything to operate. The recurrent costs of operating and maintaining are nominal. (Occasional topping up of distilled water in the battery and cleaning the panels of dust).
Individual SPV modules of a solar array can be readjusted in size to meet individual or group demands.
It is highly reliable as compared to diesel or wind-powered generators, because supply or availability of diesel could be erratic and the wind speed depends upon time & season.
Operation and maintenance are simple and easy.
The maintenance is easy. SPV panels have to be cleaned periodically. The main maintenance is of the batteries.
It lasts a long time with only a small amount of degeneration in performance over 15 years.

Environmental and Efficiency Implications
SPV systems could provide national economic
benefits as it would reduce reliance on imported fossil fuels.

SPV systems are economically viable. Taking into consideration the high reliability of SPV, many small-scale applications can be more economically powered by this system than with diesel or other small power systems.

SPV systems are environmentally friendly.
Their use protects the ecology and environment from degradation through the conservation of forests and reduction in the emission of harmful gases. A SPV system is a carbon dioxide free and clean energy converter.

SPV modules provide an independent, reliable power
source at the point of use, making it suitable for remote or inaccessible places such as hills and mountains. The majority of the population living in dispersed communities in rural areas away from the main power grid could be supplied with electricity without difficulty.

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Solar Lantern

This is a portable lighting device (florescent lamp) powered by solar radiation or a PV (photo volatic) array. It can supply a few hours of bright light a day (suitable for reading) without using any conventional fuels or AC main grid power connections.

The lantern can be used in remote areas without electricity. The solar lantern is ideal for campers, researchers, remote classrooms, rural park offices, and military and police use.

The SOLANT 7 model of solar lanterns (with a 7 watt florescent lamp) manufactured by Lotus Energy, Nepal, is a durable and rugged product that can give three to four hours of bright light per day, with optional DC output. (It can be set at from 1.5 – 12 Volts DC). It can also supply power to other appliances such as radios, LCD TV, small computers, and so on. (See diagram above).

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Improved Water Mill

A traditional water mill is a product of the local peoples? initiative and innovativeness based on local needs, materials, and skills. The improved water mill is a
modfied version of a traditional water mill. It can change the hydropower (kinetic energy) of falling water into mechanical power.?

There are two versions of improved water mills:
The first version is called an improved ghatta (water mill)
The second version is called a Multi Purpose Power Unit (MPPU)

Improved Ghatta and MPPU versions of improved water mills, besides having the basic features and functions of the traditional type, are also more versatile in the context of the additional processing needs of rural areas. The design and construction features of certain components of the traditional water mill are improved upon or moderately altered in order to increase its functional range and capacity, thereby increasing its operational efficiency as well as making it more useful with additional machines.

The mechanical power generated from the improved water mill can be used mainly to process local agricultural produce, for generating micro-level electricity, pumping up water, and, if tried, to pull or tow, i.e., the rural cross-river mechanism. Depending on
the head and water quantity, the power output can range from two to five kW or even 10hp and machines can easily be fitted such as a rice huller, oil expeller, dynamo (12V-DC OR 220V-AC). This could allow a small-scale cottage industry to run wood saws, planers, looms, etc. The MPPU can be used as a complete set: turbine, mill and electrical unit are
detachable and also have separate pieces.

Suitability for Mountain Use

Advantages
Improved water mills do away with the inherent defects and deficiencies in design, constructional features, and the operational mode of the traditional type of water mill.

It makes better use of water resources, through increased capacity, speed, and efficiency. It diversifies the usefulness of a traditional water mill from only grinding of grains to additional functions such as paddy
rice dehusking/polishing, oil expelling from oil seeds, generating electricity power, etc.

Both can be operated and maintained by the same operator of the traditional water mill after he/she has been provided with short orientation training.

Both serve the agro-processing needs for small quantities of agricultural products of people in the remote areas for domestic consumption or for rural markets.

They can help to provide electricity to small villages and rural areas and can run small-scale cottage industries based on electricity.

The improved water mills? increased capacity can serve more people (customers) as well as save time (in waiting & processing), particularly during seasonal peak periods. This gives more time for other income-generating activities.

Environmental and Efficiency
Implications
The water used in operating the mill can be reused and it is not polluted. Hence water can be used by people downstream as well as by those upstream.
It is a water-driven, non-exhaust producing machine. Hence it does not create air pollution. It does not make a loud noise during operation. Hence there is no noise pollution, except inside the millhouse.

It is housed in a small millhouse constructed with locally available materials such as timber, stones, mud, thatch, and bamboo. Hence it does not create a deforestation problem because of its limited use of
wood.

Its location near the water source and its requirement of a short (in many cases, less than 100m) and small canal hardly requires any hill-slope cutting. Hence, hill-slope stability is not disturbed.

The electricity that is generated can be used to help light up the remote village households?, for which purpose they would otherwise have to cut down trees. Hence it saves sound trees annually in its locality. Its increased efficiency can improve the quality of the produce as it can grind cereals to finer particles.

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Mini- and Micro-hydropower

{pic:023.jpg}Traditionally energy in mountain areas has been used for domestic requirements (cooking, heating, lighting, and processing), agriculture (ploughing, planting, irrigation, harvesting, threshing, etc), cottage industries (processing heat and motive power), and so on.

In almost all these cases, the predominant source of energy has been fuelwood, other biomass, and animal or manual power. The unavailability of appropriate and adequate energy sources usually results in damage to the environment through excessive and unsustainable use of fuelwood and other biomass.

A supply of energy in a suitable form is considered to be one of the main inputs required to raise the standards of living of mountain people and to minimise damage to the ecosystem. Therefore, it is necessary to place more emphasis upon renewable, locally
available, low cost and environmentally friendly energy sources.

Mini- and micro-hydropower (MMHP) is an indigenous and renewable source of energy for which potential exists in almost the whole Hindu Kush-Himalayan region.

The Advantages of MMHP
The costs of MMHP can be curtailed considerably by avoiding expensive control systems.The plants are comparatively easy to install indigenously, thus boosting employment. economic activity, and the industrial base.
Organisation and management costs are much lower than for other systems, especially in the private sector.
Micro-hydropower plants (MHP- up to 100kW capacity), being simple, are relatively easier to maintain than diesel engines.

The adverse environmental effects are minimal. For example, even if an MMHP plant were to break down completely, damage to the surrounding areas would be minimal.

Some drawbacks do exist, the main amongst them being higher capital costs, more land requirement, and specific locations that may not be suitable from the
point of view of business. Diesel plants, on the other hand, can be located and relocated anywhere quite easily. Despite the above drawbacks, MMHP plants are more viable economically on the basis of `life-cycle costs and returns’, because no fuel is required.

ICIMOD has been actively engaged in promoting MMHP plants in the HKH Region as a viable and eco-friendly source of energy for meeting the different energy needs of remote, inaccessible, underdeveloped, and sparsely-populated mountain areas. Because of its
important advantages, ICIMOD has been working at various levels to generate support for MMHP.

A sample survey to learn about the functional and economic status of existing private micro-hydropower plants was designed and is being carried out. Suitable agencies in three participating countries, namely, India, Nepal, and Pakistan, were identified and their past work, achievements, and future needs, particularly in terms of training and output improvement, were assessed. Cooperation with them will be strengthened. A number of individuals and organisations has been identified in Nepal to prepare five information manuals on various aspects of MMHP development for various groups; including surveyors, installers, manufacturers, managers, operators, and repairers.

Thus ICIMOD has been advocating at various levels and providing inputs for the enhanced use of MMHP; believing that it can contribute to the Centre’s dual mandate of poverty alleviation and environmental conservation in the HKH.

For more information, contact:
Dr. Anwar A. Junejo? Coordinator
Mini- and Micro-hydropower Project
? Mountain Enterprises and Infrastructure
E-mail: junejo@icimod.org.np

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Small Scale Windmill

A windmill or wind turbine is a device that taps the renewable kinetic energy of blowing wind to convert to useable mechanical, electrical, or thermal energy.

Some probable uses of wind energy are: generation of electricity (for modest rural electrification),heat generation (heating water, air space), agro-processing, and pumping water for domestic use or irrigation.

Some features of wind are as follow.
Wind is light in weight
There is high output of energy in low wind speeds
There are a wide range of working wind speeds
Using wind energy can produce high efficiency
Windmill devices are run by wind energy. Quite a variety of windmills of different capacities are available to suit local conditions. (See diagram above.)

Suitability for Mountain Use

Advantages
Wind is renewable/inexhaustible.
It is locally available at zero cost for procurement.
It has a variety of uses even in remote areas.
Wind energy could be much cheaper than wood or kerosene.

The use of wind energy may be limited by a high initial cost, dependability is subject to site conditions, and minute-to-minute variations in speed.

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Bijuli Dekchi

To promote the use of electricity in rural areas thereby relieving the pressure on fuelwood demand for heating and cooking, effective end-use appliances are necessary. The Bijuli Dekchi is one such means that makes cooking by electricity a viable alternative to
firewood. It can be used for such purposes as:
heating hot water continuously
heating milk and tea.
cooking food
frying (however, frying requires a high voltage).

The Bijuli Dekchi (BD) consists of two locally available aluminium pots of slightly different sizes which are fitted into each other with an air gap in between. This acts as an insulator between the inner pot with its contents and the outside air and reduces heat loss through the side and base, resulting in a highly efficient cooker. Its efficiency could be as high as 80%.

Low wattage flat heating elements are attached to the underside of the inner pot. The rims of each pair of pots are crimped together. A thermostat is installed to prevent the pan from boiling over and to turn the dekchi into an automatic rice cooker that can keepfood warm for several hours.

The maximum temperature for the small cooker is limited by the thermostat to 120oC to prevent the rice or other food from burning. For the large cooker (used for heating water), the limit is set at 80oC to reduce the chances of the pot boiling dry, as it is usually left unattended for many hours at a time.

The BD has a low-high switch which regulates the night time heating of water at half the original wattage of the cooker. It has an average efficiency of 65% (against 15% for a fuelwood stove).

The cookers come in various sizes to suit the demands of users:
capacity ranges from 3 – 40 litres
energy consumption ranges from 200 – 1,000 watts (electricity).

Suitability for Mountain Use

Advantages
It encourages the use of electricity in off-peak hours for heating water and cooking.
Its use increases the load factor in the off-peak hours. This helps to reduce the initial investment requirements for electricity (micro-hydro) plants by decreasing the high peak power capacity, while it helps to increase revenue by increasing the total load factor.

It is highly efficient (65%) and has a good heat retention capability.
It is a simple design, handy and easy to transport.
In areas using flat-rate tariffs for electricity supply, the households with 200-watt connections and above can cook using their fixed connection and it is almost free of cost.
There is no danger of short-circuiting or fire.
It is convenient as there is no need to watch over it.
It is easy to clean.
It does no harm to users – it does not produce smoke.
It helps reduce firewood consumption – it is economical, thus it saves money.

Environmental and Efficiency
Implications
The BD has effectively proved (in the Ghandruk area in Nepal) that it can be a highly useful cooking aid in places where there is a shortage of fuel due to environmental reasons or due to a shortage of labour.?

Use of the BD has been seen to reduce firewood consumption and thus help conserve forest resources.
Since the BD can be used continuously for heating water and storing heat in the form of hot water, it gainfully uses the fixed power connection.
It produces no negative environmental impacts.
The BD decreases the maximum load required for cooking considerably (from about 1,000 down to 200 watts).

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Back Boiler

This is a water heating technology in which cold water is circulated through a hearth and hot water is received continously. Thus a Back Boiler heats water continuously.

The system consists of:
a cooking hearth (traditional or improved),
a galvanised iron drum of about 220 litres? capacity,and
a pipeline from the water drum to and through the hearth and back to the water drum.

Cold water is run into the water drum and from the bottom it is circulated through the hearth under gravity. The water is heated through the heat generated in the hearth. The hot water in the pipeline passing through the hearth returns to the same water drum on top of the cold water already contained inside. Hot water can then be received directly fromit. (See diagram above).

Suitability for Mountain Use

Advantages
The back boiler is very simple to build and operate.
It is fairly inexpensive.

Environmental and Efficiency Implications
It reduces significantly the amount of fuelwood needed for heating water.
It has been estimated that an average of 675kg of fuelwood is saved per month, per lodge during the peak tourist season in Ghandruk in the Annapurna Conservation Area of Nepal; a net reduction of 23% in fuelwood use.

This technology is suitable for cold and very cold climates. Being a simple technology, it can be easily installed by people who can afford it, but its wide use at household level would increase fuelwood consumption. It is currently widely used in the Annapurna Conservation Area, Nepal.

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Solar Passive Space Heating System

Solar heat can be used for space heating in order to provide adequate warmth inside houses, lodges, restaurants, and other facilities in the hills and mountains. A solar space heating system can be: an active system which requires conventional energy to operate it, or a passive system which operates entirely on the renewable energy available in the immediate environment.

The passive heating of buildings through solar energy involves the integration of the system into the structure of the building itself. The system works in three ways:

collection of sun rays,
storage of the heat collected, and
release of the heat in a useful way.

Passive heating of buildings is achieved by understanding and using the knowledge of heat and its effects on different building materials. Operation of the passive heating system takes advantage of the natural characteristics of materials such as those given below.

The convective flow of air and water
The absorption qualities of dark colours and dense materials
The heat storing properties of dense materials and water
The poor heat conductivity of insulating materials.

The buildings are designed in such a way that the heating needs of the occupants are performed with the sun as a heat source and the night sky as a heat sink.The various passive solar space heating systems need very little maintenance.

Suitability for Mountain Use

Advantages
A passive heating system does not need any devices or power to operate it.
It does not use up resources.
In most cases, the system can be constructed from environmentally clean materials such as earth, rocks, water, and iron.

Environmental and Efficiency
Implications?
Environmentally friendly
The efficiency depends on the materials used for construction and their thickness.

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?????? Some Variations in Cooking and/or Heating Stoves

Stoves for cooking and heating rooms/water can be found in different shapes and sizes. The stoves are generally improved versions of the traditional cooking stoves. Ceramics, straw, mud, cast iron, mild steel, and sheet steel is used to make these stoves. The whole body of the stove can be made of:
mud and ceramics,
cast iron (KTS model based on a western design),
cast iron plate on top of a mud and stone body,
cast iron plate on top of a mild steel body, or
a metal cover around a stone/mud body to protect the stove from the cold.

The stoves could have 2 – 3 pot holes of different sizes; the shape can be oval or rectangular; it can come with or without a baffle made of mud or other materials; a
chimney may or may not be provided with a damper fuel control; and circulating or non-circulating water heating systems (back boiler) may or may not be attached (somewhere between the second pot hole and chimney).

The stoves produce plenty of heat in the room. The cast iron stoves produce more heat while ones with a stone/mud body and cast iron plate produce moderate heat.

Suitability for Mountain Use

Advantages
The stoves produce plenty of heat

Environmental and Efficiency
Implications
The cast iron stoves produce more heat while the ones with a stone/mud body and cast iron plate produce moderate heat.

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Solar Dryer for Agricultural Produce

Any food or agricultural product with high moisture contents is easily attacked by insects and rots quite quickly. To guard against such possibilities and to preserve food for longer periods, the food needs to be dried.

The traditional method of drying is to spread the food openly in the sun. In this drying method, the food is often contaminated by dust and birds. A percentage is lost or damaged due to insects/birds.

A solar dryer is an enclosed unit, so the food is safe from damage, birds, and insects.The food is dried using solar thermal energy in a cleaner and healthier way. This is a passive system of heating using only solar and wind energy in its operation.

Solar dryers can be made in different sizes and shapes based on the quantity and type of food to be dried. The size and shape also depend on domestic or commercial use. There is quite a variety of solar dryers. Some solar dryers can be made out of locally available
materials in the hills and mountains. These are the:
cabinet solar dryer,
flat solar dryer, and
tent solar dryer.

A solar dryer can be used to dry a variety of agricultural products and foodstuffs such as:
fruits (grapes, bananas),
vegetables (potatoes, onions),
grains (paddy, wheat, maize, millet),
spices (ginger, garlic, chillis),
cash crops (coffee, herbs, flowers), and fish.

How a solar dryer works

Solar rays entering the cabinet through the solar collector are converted into heat energy raising the temperature inside. The heat energy is transferred to the food to be dried. The heated food gives out water vapour and dries up gradually. The heated moist air leaves the cabinet and dry air enters in a natural and conventional process.

Suitability for Mountain Use

Advantages
It is a simple and cheap technology.
It can dry agricultural products in a healthier and safer way, i.e., out of the reach of insects, dust, birds, dirt, and
smoke.?
It dries food faster than open drying in the sun.
It dries by keeping the physio-chemical quality (colour, taste, and aroma) of the dried food intact or even improving it.
It uses a renewable, easy, local, and freely available source of energy.
It can easily be made by local craftsmen like carpenters or by family members after observation of a model or a short orientation course on how to make one.

Environmental and Efficiency
Implications
It in no way creates pollution to air, water, or land.
It is generally kept on the roof so does not pose aesthetic disturbances.
It dries the food/produce much faster than open drying in the sun.
Less food is lost due to contamination and insects/birds.

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Source: http://www.icimod.org/sus_options/bestprac3.htm