APROJECT IMPLEMENTED BY UK-based IT Power in the Indian Himalayas is helping local millers upgrade their traditional watermills with locally made crossflow turbines.
Building on similar experiences in Nepal, the technical designs have been simplified to involve minimum components and permit robust manufacture.
The crossflows have no casing and use an overhung runner located outside the mill house. The shaft entering the mill house ends in a three-groove pulley from which three machines can be operated without the need for line-shafting.
Another feature has been the casting of the crossflow runner in one piece, providing a design resistant to the fatigue-cracking that has hampered many locally made crossflows, says the company.
A 5kW scheme will cost around US$600/kW (50% for channel and power house and 50% for the turbine and penstock). A 5kW rice huller can de-husk up to 100kg of rice per hour, for which the miller earns 3.5 US cents/kg. Relating income to energy consumption yields a value of 70 US cents/kWh – at least ten times the value of electricity.
If the miller can de-husk 200kg a day for 200 days per year, he will pay back the investment in less than three years.
Those involved in the project say that these numbers reiterate the fact that agro-processing end-uses can justify new micro hydro projects without the need for subsidy.
‘We believe that these low cost micro hydro systems will prove to be an effective and sustainable way of meeting the energy needs of a significant section of the rural poor in hilly areas,’ said Oliver Paish, senior engineer at IT Power.