Small River Hydro Turning the Lights On in Nepal
People living in remote Himalayan villages could potentially be among the last to enjoy the benefits of electricity. The terrain is steep and harsh, and sunshine is fleeting in the deep valleys where most settlements are found. The locations are often extremely difficult to reach. Schools are small and children in Nepal wishing to go past grade 7 must travel to larger cities like Katmandu, from which they seldom return. Resources are scarce, but one thing they have in abundance is plenty of fast-moving water, snow-melt runoff from the greatest mountains in the world.
The non-profit Himalaya Currents, in conjunction with the World Wildlife Fund (WWF), seeing the opportunity, partnered with New Energy Corporation, makers of hydro-kinetic turbines, Advantage Products, and US Synthetic , makers of synthetic diamonds, to develop a clean energy system capable of providing continuous, clean, renewable energy to the villagers. If you're wondering where the diamonds come in, keep reading.
Working together, they installed a 5 kW EnCurrent hydro-kinetic electric power system, submerged in a flume a nearby river, close to the village of Ringmo, high in Nepal's Dolpa region.
These systems are well suited to installations like this, requiring no dams, penstocks, or any of the elaborate civil works generally associated with hydro-power, other than a gabion, which is a cage filled with rocks that forms a wall, and a flume. These were both constructed with the enthusiastic support of local community members who provided much of the manpower. This technology was also a good fit considering the fact that all the equipment had to be carried in by porters and pony caravans to the very remote location, three days' walk from the nearest airstrip, and six days' walk from the nearest road.
Said Clayton Bear, President of New Energy Systems, “we quickly recognized the need to make our system as simple and lightweight as possible. So, we scrapped the gearbox and focused on a simple above-water direct drive hydro-kinetic generator using a submerged water lubricated PCD bearing for the turbine rotor. This design breaks the system down into small enough components that can be carried by porters and assembled on site with hand tools.”
The PCD bearing referred to is the polycrystalline diamond bearing, which is an essential element in making the system work. Given the amount of sediment and debris that is picked up as the water rushes down from the mountains: mud, sand and gravel, all create a tremendous amount of abrasion on the system elements. This would quickly destroy any of the traditional sealed bearings that are typically used in rotating equipment, bringing the turbine to a grinding halt while also releasing the petroleum-based lubricants into the water.
The polycrystalline diamond bearings from US Synthetic are ideally suited for this application. They are water lubricated, which makes the system virtually maintenance-free. The system will run continuously, twenty-four hours a day, providing lights and a satellite connection to link the residents of Ringmo with the rest of the world. A system like this is highly reproducible and well suited to thousands of similar locations around the world, bringing in constant, clean electricity with little to no environmental impact.
[Image courtesy of New Energy Systems]