The New Metal Gharat: A Simple Application of the Power of Water
A modern version of a traditional tool, the gharat, or small water-powered turbine, is part of an ecologically sustainable economic revolution that is taking place in some remote Indian villages in the Himalayas.
The traditional wooden water turbine, widely used at one time, has been on the decline because of its inefficiency and the cost of building and maintaining it. Newer wheels, developed and popularized by a former botany professor named Anil Joshi, have brought significant improvements to many remote areas of rural northern India. Joshi launched a grass-roots movement to help Himalayan villagers stop using coal-intensive power and instead turn the region’s thousands of fast-flowing streams into personal mini hydro-electric power stations.
The new gharat, a water wheel with steel blades, grinds grain, presses oil, and generates electricity for remote villages where electricity is otherwise unavailable. A single steel-bladed wheel can produce electricity at night for as many as 60 homes. Usually the small turbines are used to provide hydro power for small-scale industry by day and for generating electricity by night.
Water wheels are a centuries-old technology in the Himalayas, but one that was becoming obsolete until Joshi and an organization he founded three decades ago taught villagers to develop alternative livelihoods by modernizing the wheels and using them for traditional industry during the day and to provide electric power for village homes at night.
Improving the technology was key to Joshi’s strategy. The old water wheels were inefficient, taking a day to crush around 10 kilos (22 pounds) of wheat. Making a single wheel was a laborious process that required the wood from an entire pine or cedar tree. And environmental considerations had led to restrictions on tree-felling, which drove up the price of timber.
Joshi did much to improve the traditional gharats by fitting them with modern gears and ball bearings, but the main innovation was the introduction of steel for the turbine blades. Wooden wheels were liable to break when torrential monsoon rains washed rocks downstream, and repairing the blades was time-consuming and costly.
The most recent improvement has been the change to the horizontal turbine to replace the traditional vertical model.
Many of the hill streams which drive the small turbines come down with tremendous force and as much as 1/5 of the generative capability is lost by the crashing of the water into the turbine vertically. Much capacity is gained with the use of the horizontal turbine.
The redesigned gharat represents an exemplary use of simple resources to improve the world without destroying it. Using the free energy from the streams rather than diesel generators or nuclear power creates a clean, sustainable power source.
Reference: The Christian Science Monitor.