Technologists at IIT-Madras have developed a turbine for run-of-the-river plants with low water depth. The turbine can be placed where the water depth is less than 4.5 m and flow rate is only 3 m per second.
The turbine is horizontal, which means the water flows through it and turns the blades at a speed of 1,500 rpm. Prof Dhiman Chatterjee of the Hydro Turbo Machines Lab of the Department of Mechanical Engineering, told Quantum that the rated capacity of the lab-tested device is 9kW, but the one built for field trials would have 100kW capacity.
The energy for conversion into electricity comes from both the flow of the river and the pressure from the head of the water — the machine converts around 73 per cent of this energy into electricity. Dr Chatterjee said the team is “looking for opportunities for funding and a place to do field-level tests”.
For field tests, the only addition, apart from upscaling the capacity, would be to integrate a generator to produce electricity. The only other challenge is the likely damage to the blades from silt, for which the team is working with IIT-M metallurgy department for an appropriate surface coating. Dr Chatterjee said the turbines have high potential for commercial deployment. It can be put up in Himalayan rivers, at places where there is a good slope, or in other places by building a small check-dam and a diversion canal to place the turbine.