Gharats of Uttaranchal: Harnessing Natural Energy
Gharats of Uttaranchal: Harnessing Natural Energy
By Manikant Shah
Anyone living in the hills of the state of Uttaranchal in India would know what a gharat is. The somewhat subdued rolling sound of a continuous friction between heavy stones near the river betrays the presence of a gharat nearby. These gharats have a momentous role in utilization of mechanical power from water streams mainly for grinding purpose.
Man has always tried to develop technology that converts energy from a natural resource into an energy he can harness to his advantage. As elsewhere, the people inhabiting the mountainous tracts of Uttaranchal too apparently found themselves constrained by the harsh physical conditions of the region. Yet the environment did not cow them down. They neither relapsed into inactivity and contentment with destiny nor they chose to frantically employ their energies to overpower and exploit the nature. Rather, they found ways to harness the flowing energy of the natural resources to their advantage. Apart from other natural features, the Himalayan regions are well known for their gushing rivers and streams directly fed by the snowy Himalayan Mountains. Besides the melting snows of the Himalayas, there are numerous other rain-fed tributaries that sustain and enhance the water flow in the rivers. In fact, the upper reaches of Uttaranchal are known as the water-repository of India. People in the past realized the natural potential of these gushing waters as an unceasing energy resource and utilized its potential in very many ways. One of the remarkable ways in which they utilized the natural resource was by way of the gharats. Constructions similar to gharats and working on a similar principle are known in the west as watermills.
Generally it is believed that the gharats originated somewhere in the Northeast region around the 7th century. But there is no consensus over the date. Currently gharats are in wide use in the whole of the Himalayan range and the Northeast. The populations of the Himalayas, from Afghanistan to Myanmar, still live predominantly in agricultural economies, often at subsistence level. The need for milling is reasonably well served by traditional watermills spread throughout the region. According to some estimates there are over 500,000 watermills in this entire region.
We made a detailed study of this traditional technology: how it could bee upgraded to fit in with the modern times and requirements, as also for the benefit of the poor people of the Himalayan region. We will therefore have to go into a bit of technical detail.
It is interesting to study the ingenious mechanism of these gharats.
There are three distinct types of water mills. The simplest and probably the earliest was a vertical wheel with paddles on which the force of the stream acted. Next was the horizontal wheel, with a vertical shaft attached directly to the wheel used for driving a millstone. Third was the geared mill, driven by a vertical waterwheel with a horizontal shaft. This required more knowledge and engineering skill than the first two, but it shows greater potential. Vertical waterwheels are also distinguished by the location of water contact with the wheel, as the undershot wheel, the breast wheel, the overshot wheel and the Baker wheel. These waterwheels generally use the energy of moving streams. Each type of mill has its particular advantages and disadvantages. Relatively little is known of their development before the Middle Ages.
The Report on the Industrial Survey of the Garhwal district of the United Provinces and the Report on the Industrial Survey of the Almora district of the United Provinces compiled by H.N. Sapru in 1924 and 1925 respectively, as part of the general scheme of the Industrial survey of the whole province under the British regime, gives due importance to these watermills. The reports point out that there were as many as 5,000 watermills in district Almora and 2,956 watermills in the Garhwal district at the time of the compilation of the reports. However, the actual number of these mills in the hills even in those times must have been much more for all may not have been reported for the obvious difficulty of surveying remote areas in those days, a fact which Mr. Sapru himself conceded. In these reports a large portion of Uttaranchal hills known then as the Tehri State were not included.
The traditional Himalayan water mill or the gharat is of the vertical shaft type. The gharats in Uttaranchal can be found alongside the rivers. To run these mills a channel is dug along the river to carry the water up to the mill-house. The gradient of the channel for the flow of the diverted water is less than the gradient of the river. With this, after several hundred meters from the diversion, a fall of 2 to 6 meters is achieved for the water. In this manner water from the stream is tapped and routed through the chute, which then falls on the flat blades. The water chute consists of an open channel either made from wooden planks or carved from a large tree trunk. The chute is narrowed down towards the lower end forming a nozzle. The force of the water let through the chute with a head of 2 to 6 meters strikes the blades and rotates the wheel, which in turn, rotates the metal shaft. The head of the water varies from place to place depending upon the availability of the fall.
The wooden blades are fitted to a thick vertical wooden shaft, tapering at both ends. Two round millstones, hewn locally, are fitted at the top of the shaft to act as the grinding mill. The wooden shaft of the turbine is supported on a stone pivot through a steel pin and held in the sliding bearing at the top. The sliding bearing is a wooden bush fixed in the lower stationary grinding stone. The top-grinding wheel rests on the lower stone and is rotated by the turbine shaft through a straight slot coupling. The gap between the stone is adjusted by lifting the upper stone with the help of a mechanical lever. The blades vary in number in different gharats from 11 to 21, which is fixed lengthwise at the axis to transmit the entire load to an iron base. At opposite end from the cylindrical axis, a long shaft connects it to the upper part of the grinder stone. It is interesting to note that the fitness and quality of grain can be determined even in this nature-run process for which a groove is made into the upper grinder to set a tapered iron piece that holds the shaft and grinder simultaneously. An iron base bears the load of the system that in turn diffuses it over the horizontally laid plank. One end of the plank is attached to an adjusting lever, which moves upward and downward. The lever governs the distance between the moving and the stationary part of the grinder. An upward movement of the lever allows for coarse grinding while the downward is for fine grinding. Traditionally, channels divert the water from stream/ river to the mill. A device is also incorporated in the channel to divert the water if the water mill is not in operation. This device redirects water. It’s a simple but an ingenious construction and can be maintained with simple understanding of the principles involved.
The components of a gharat may be listed as follows:
1. Flume or chute: A wooden drain kind of thing that routes and rushes the water from the diverted channel to the rotor blades attached to the vertical shaft.
2. Grain Feeder: A bag or funnel, which feeds grains to the grinding millstones.
3. Bearing: That helps the upper grinding stone to rotate freely.
4. Upper Grinding or milling stones: The circular Upper grinding stone of the mill that is directly attached to the shaft and rotates with it.
5. Lower Grinding or milling stones: The circular lower grinding mill stone through the middle of which the shaft rod passes to support the upper grinding stone. This lower grinding stone remains stationary.
6. Bush: A round wooden or a leather piece fitted to the hole in the lower grinding stone through which the shaft rod passes.
7. The vertical shaft: The wooden or iron rod that connects the rotating fan down below with the upper grinding stone.
8. Runner with hub: The thick wooden portion to which the fans are fitted and which determines the speed of the rotation of the shaft.
9. Lifting mechanism lever: A wooden mechanism that determines the coarseness or the fineness of the grains being ground.
10. Bearing: The point at which the pin of the shaft rests giving free rotation.
These gharats are constructed from locally available material such as wood, stones, bamboo, and reeds. Apart from the technological aspect. these gharats also have an important sociological dimension. Socially, they have been the meeting points for villagers to get together. The widespread use of gharats and its popularity owe much to its simple and cost effective mechanism. It is important to note the advantages inherent in the indigenous watermill technology, in particular:
- Simple technology
- Locally designed and built
- Involving mainly local materials
- Low capital cost
- Almost no running costs
- Easily managed and maintained
- Better taste of the ground material
Improvements to the gharats and Power Generation
Grain-milling is the most widespread use of hydro-power in the Himalayas. Traditional wooden watermills (gharats) have been used for centuries. However in recent years, gharats have started to fall into disuse due to various contributory factors. The State, especially the British, other than collecting water tax from the gharat by and large ignored them. The importance of gharats was further overshadowed by the introduction of the diesel and electric powered mills and the inclination of the people towards the speed grinding machines. The owners of these gharats were forced to descend to the plains to seek more lucrative employment. Another factor has been the major deforestation of the hilly regions that has caused the resulted in water supplies to diminish or disappear altogether.
The design of traditional water mills is centuries old. Because of having extremely low output these mills do not provide enough profit to the mill owners. Increasing the output of these mills by developing efficient mill design would undoubtedly bring significant increase and end use applications. This feeling has encouraged the technologists to improve the existing design of the gharat. There are potentially two kinds of improvement that can be worked upon the gharats. The first involves whereby the efficiency of the present gharats can be improved. The second, which is more important in the present times, is whereby power may be generated from these gharats.
The estimates of the number of gharats in the Indian Himalayan region (IMR), which stretches from Kashmir to Arunchal Pradesh, vary from 100,000 to 200,000 but their number in Uttaranchal can be estimated with more precision. There could be as many as 60,000 gharats in Uttaranchal according to the study of HESCO.
Gharats cost the owner anything between 5000- 7000 rupees, and have to be replaced every 2- 3 years. These gharats have efficiencies ranging from 10%- 15% only. This indigenous technology is built and maintained by the miller himself using local materials but is limited to outputs in the range 5-10 kg of flour per hour. If this abundant and renewable waterpower resource could be exploited more effectively with appropriate and modernized equipment, it could play a key role in driving sustainable economic development in the hilly regions. This is a task, which the India Hilly Hydro Project is endeavoring to address. It is pointed out that with a little technical enrichment input the efficiency of these mills can be increased by 30 to 40%. The UNDP-GEF Hilly Hydro Project is an ongoing initiative supported by the World Bank Global Environment Facility and the Government of India to demonstrate and promote the use of small-scale hydropower in the 13 Himalayan states of India. The Himalayan Environmental Studies and Conservation Organisation (HESCO), an Indian NGO based in Chamoli District, has also been working towards the improvement of the gharats in the Uttaranchal region.
The gharat upgrade involves replacing the wooden runner with a steel casting and ball bearing. To gain another 30% of power, the open chute can be replaced with a PVC pipe and spear valve. The net result is to supply around 1kW of shaft power to the millstones. The new machine costs just the same and has an extended life span of 30% of the old machines. Additionally, the owner is saved the trouble of replacing the machine every 2 to 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. The traditional wooden runner is less than 20% efficient. The design objective was to develop a runner, which can exceed 50% efficiency, but also have a geometry suitable either for casting, or low-cost welded fabrication. Furthermore, this design of runner is suitable for converting to a horizontal axis layout at a later date. The new runner is an outward flow design – the water strikes the inside edge of the blades and escapes tangentially. The new runner is smaller and faster running than the traditional gharat, with speeds in the range 200-250 rpm.
The Himalayan Environmental Studies and Conservation Organisation (HESCO), an Indian NGO based in Chamoli District, UP, was responsible for setting up the Gharat Owners’ Association in Chamoli and has been working with them to design and implement simple upgrades for traditional gharats. The improvements have involved lining the open chute with galvanised steel sheet, using a Teflon bush for the top-bearing (at the centre of the bed-stone), and using a fabricated ball-bearing assembly as the footstep bearing at the base of the rotor. About 12 gharats have been upgraded to date in Chamoli District. The component and material costs are about Rs. 1500/- and the miller himself undertakes the upgrade work. Increased output of 2-3 times has been experienced, with stone speed increasing typically from 70 to 120 rpm. With this upgrade the millers can grind at least 15kg of wheat per hour. They traditionally keep 5% of the flour as payment-in-kind, which can be sold for 5Rs/kg (or more). Equating income against energy use leads to a value for the energy of 3.75Rs/kWh. This is 2-3 times the income that could be earned using the same power to generate electricity, but at a fraction of the investment cost.
Although the old millstones can be used, it is important that they are ‘dressed’ by cutting a pattern of grooves in both stones. This allows the stones to mill efficiently using the greater power provided by the new runner, otherwise they may get hot and damage the flour, or even break.
Improving traditional watermills would benefit:
- Millers and their families whose economic situation will be improved by greater productivity and income-generation.
- Local communities who would stand to benefit from faster and more efficient agro-processing services, a wider range of mechanized crop-processing machinery, plus electrical services via an add-on generator, such as evening lighting, or water-heating, battery-charging, crop-drying, or irrigation pumping at night.
- Women, who will have a reduced burden of either manual crop-processing, or of hours or days of walking to electric or diesel machines.
- Manufacturers, who will have the possibility of producing and selling large batches of simple, standardized equipment.
- Local workshops, which will be needed to supply components and spares, or provide repair services, or which may choose to develop/copy their own watermill upgrade.
- The environment, by displacing harmful emissions and reducing the reliance on wood-fuel
The improved gharat costs about Rs.15,000 (~$300) for all components, including some civil works. The jet of water can be provided either by the traditional wooden chute, or by a PVC pipe with a nozzle. The chute is less efficient, so needs more water to get the same output. If the old wooden chute is used, the cost for only replacing the runner is around Rs. 6000 (~$130). These modifications increase the grinding rate to between 15 and 30 kg per hour.
Energy consumption and its availability play a vital role in the development of an area. Average energy availability and consumption of an urban dweller is more than hundred times than that of a villager living in rural remote areas. So a major part of the energy requirements by way of power in the hills of Uttaranchal can be met by the modification of the gharats. Modern dams use similar technology except that the stored water is funneled through channels or pipes that push this high-pressure water through the blades of a turbine. This turbine generates electricity.
As pointed out earlier there are approximately 60,000 gharats, each producing on the average about 1.5 KW power, which can be increased up to 5 KW per gharat by a little extra technical input. 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: ¾ higher income levels, more time for recreation and study, and ability to undertake additional economic activities.
Researchers at the Tata Energy Research Institute (TERI), Alternate Hydro Energy Centre, University of Roorkee and IT Power Limited, United Kingdom too have jointly developed a novel technique of increasing the efficiencies of these mills, sometimes by up to 1500%. It’s not the speed of the water that’s important; it’s the volume, force and drop (the higher the drop and more volume, the more force). There are two main categories of hydroelectric power generation: conventional methods, which produce electricity via water flow in one direction (and are therefore dependent on seasonal runoff), and pumped storage methods, which are both producers and consumers of electricity as the water used to generate electricity can be recycled by pumping it back uphill. A water turbine uses the potential energy resulting from the difference in elevation between an upstream water reservoir and the turbine-exit water level (the tailrace) to convert this so-called head into work. Water turbines are the modern successors of simple waterwheels, which date back about 2,000 years. Today, the primary use of water turbines is for electric power generation. The new system replaces the wooden waterwheel with a cast steel runner mounted on a steel shaft. The new runner fits under the existing mill-house and can use the same millstones. The shaft is mounted on a ball bearing at the bottom and runs in a wooden bearing inserted into the bottom millstone.
Technological up gradation through intervention by voluntary sector has improved the functional efficiency of the watermills and also made it possible to generate power. A few of these upgraded watermills have been field tested and propagated by HESCO in a few Himalayan regions.
Nepal is the only country where significant progress has been made to upgrade watermill designs, where development occurred in 2 phases. Initially a packaged steel assembly was developed by a local workshop, which incorporated a vertical-axis impulse turbine made with fabricated steel buckets and a penstock pipe. There has been more than one attempt in India to copy and disseminate the Nepali design of watermill upgrade but these initiatives have failed to make a significant impact, through either institutional reasons (highly subsidized; no training or technical support; owners not helped to develop their businesses), or technical reasons (designs were copied; not understood and transferred; so systems were inappropriately specified and installed).
Two types of conventional hydroelectric facilities are dams and run-of-river. Dams raise the water level of a stream or river to an elevation necessary to create a sufficient elevation difference (water pressure, or head). Run-of-river, or water diversion, facilities typically divert water from its natural channel to run it through a turbine, and then usually return the water to the channel downstream of the turbine.
We have to emphasise the tremendous value of such improvements in the traditional technologies. Gharat can lead to potential power generation of 2500 MW/hr or 40 million units of electricity and a cash generation of Rs. 1200 million per hour.
To sum, it’s a source of energy that is eco-friendly and needs to be patronized and technologically up-graded. Regretfully, this ancient device to utilize the natural energy, locally known as gharat, has largely remained neglected.
Considering the power scene nationally, let us have a look at the following figures.
- India’s total power generation capacity from water sources 95,000 MW
- Tapped potential 22%
- Potential across Northern Mountain ranges 65,000 MW
- National requirement by 2000AD 125,000 MW
- Current power generated 78,000 MW
The technology for village-scale hydropower is generally under-researched and could benefit from R&D in a number of fields, for example:
- Hydraulic testing of alternative runner designs
- Hydraulic testing of open chutes relative to penstocks
- Design of low-cost nozzle valve or simple spear valve.
- Design and test a simple mechanical over speed trip.
- Design and testing simple mechanical governor.
- Design and testing robust generator.
- Design and testing improved footstep bearing and adjustable top bearing for gharat upgrades.
It is highly relevant and the need of the hour to formulate an independent water policy for the Himalayas. This could encompass technological up-gradation of water-millers, decentralization of technology and technical institutions, renovation of existing micro hydel projects and abolition of taxes on water-millers. The nodal agencies that need to come on a single platform are the Ministries/Deptts. of RA&E, Energy, MNES, labour, Water Resources, HRD, Forest and Environment and DST.
Our extensive explorations, though done only as a pilot study, have proved beyond doubt the potential of Uttaranchal for studying the Traditional Knowledge Systems. The study of these folk technologies and belief systems is not just an esoteric study but has also direct relevance to the socio-economic and environmental problems of Uttaranchal, as also of the world at large.
Our studies have also shown that, in contrast to the received wisdom that the Central Himalayas were an isolated region, cul de sacs, and had hardly any role to play in the historical processes of the Ganga Valley urbanisation, the Central Himalayas played a significant role in such processes. We found that the early dates of copper and iron technologies make it distinctly clear that the Copper Hoard Culture of the Ganga Valley had its typological affiliates in Pithoragarh District. With huge dumps of iron slag all over the area clearly suggests that it must have been supplied to the plains of the Ganga Valley. Thus to unravel the early urbanisation processes of the Ganga valley one has to take into account the archaeology of Uttaranchal also.
Not only the traditional copper and iron technologies are important archaeologically, but they may provide a solution to the endemic poverty of the region where majority of males have to leave their homes and hearths in search of jobs in the plains. Even today more than a thousand families are practicing copper smithy but hardly have good quality raw material. Copper production was stopped by the British way back in the nineteen thirties. The area is amply bestowed with copper and iron minerals of a high grade. The Lohaghat area was producing stainless steel utensils even fifty years back. These smallscale industries could be revived for the benefit of the local people, without disturbing the environment.
As we discussed above, the evidence from South China and Southeast Asia indicates that the early rice technology travelled with the Mon Khmer speaking people. We know that the local dialects of Uttaranchal have a distinct residue of Mon Khmer words. Only with rice sowing are associated elaborate rituals which again indicates its antiquity. If further work indicates that the early rice technology too travelled from Uttaranchal to the plains of the Ganga Valley, we wont be surprised.
The Himalayan Medicine System is a gold mine of medicinal knowledge. More than 800 plants of potent herbal medicines are found here. Instead of the Multinational companies exploiting our herbal wealth, we should allow the local people to collect, sell and grow such herbs as part of their employment schemes. In fact, as part of our continuing studies we are finding that the HMT was the real knowledge substrate for our Ayurvedic pharmacopoeia.
Traditionally watermills were run using stream water which was free. Of late though electricity is in short supply, these watermills are going out of fashion. We have suggested above that by a bit of up-gradation such watermills or gharats not only could solve the problem of grinding grains and spices but also of power shortage by modifying them to produce electricity.
Precious art and skills of woodcarving are similarly vanishing fast. They also provide a source of livelihood and satisfaction too to the craftsmen if they could be exported to the towns of the hills, plains, and even globally.
To sum, Uttaranchal provides excellent opportunities not only for studying Traditional Knowledge Systems but also the means to use traditional technologies, which are sustainable and eco-friendly, for the uplift of the poor hilly people.
Sapru H.N. 1924. Report on the Industrial Survey of the Garhwal District of the United Provinces. Government Press, U.P. Allahabad.
Sapru H.N. 1925. Report on the Industrial Survey of the Almora District of the United Provinces. Government Press, U.P. Allahabad.
Stowell V.A. 1922. A Manual of the Land Tenures of the Kumaun Division (Hill Tracts). Government Press, U.P. Allahabad.
REPORTS of the Alternate Hydro Energy Center, University of Roorkee, Roorkee Uttaranchal, India.
Internet reports of HESCO.