Abstract:
Water wheel turbines are not popularly used for water pumping or power generation in Sri Lanka.
Utilization of water-wheel-turbine for water pumping and electricity generation for rural areas has
been envisaged in this proposal. Recently, an undershot water wheel was fabricated and tested in
a drop structure of an irrigation canal in Polonnaruwa, Sri Lanka. Characteristic curve of shaft
power verses rotating speed of the water wheel was obtained during its test runs. Its special feature
is the ability to extract energy from low-head (less than 5m) water sources that have not yet been
viewed as potential energy sources. The ease of fabrication, cost and compact design were main
criteria in developing the water wheel. This study aims to extract hydropower from numerous drop
structures located in the dry zone of the country. The extracted hydropower can be used to pump
water for irrigating higher locations (lift irrigation) or for generating electricity. A 1.25 m long, 1
m diameter waterwheel can generate 1 kW of shaft power when installed in a 1 m high drop
structure with approximately 175 1/s flow rate. The efficiency of the developed prototype water
wheel needs to be further improved and at the same time an industrial version of the water wheel
needs to be designed.
