Windmill driven water pump for small-scale irrigation and domestic use : In Lake Victoria basin

Abstract: This project is a combination of mechanical engineering and sustainable development in developing countries. The goal has been to build a windmill driven water pump and to design a small-scale irrigation system for SCC-Vi Agroforestry’s demonstration farm in Musoma, Mara region, Tanzania. The purpose was to enable SCC-Vi Agroforestry to demonstrate and spread knowledge about these techniques to farmers in the region. In 2007, two students from Halmstad University conducted a field study in the Mara region and found that many farmers lack clean and running water. Back in Sweden they constructed a prototype of a windmill that employs wind energy to pump water using a semi-rotary pump. The intention is that local farmers should be able to build their own windmill, and thus have running water in their household. However, the windmill has never been built in Tanzania. The windmill construction in this report is based on the prototype, but the original drawings were changed to fit the specific situation in Tanzania better. Important throughout the project has been to minimise cost and to only use material that local farmers can get hold of. Building and assembling of the windmill were then performed by the authors in co-operation with local workers. The windmill drives a pump that pumps water from a well to a tank for further use in irrigation. Calculations have been made on the energy available in the wind and an energy analysis was then performed to see what wind speed is required for the system to work. If wind speed is low, the windmill can be adjusted by placing the connecting rod closer to the rotation centre where it requires less work to function. As a result of that, the volume of water per stroke will decrease and it will take longer time to fill the tank. This project was carried out during the rainy season when there is less wind; therefore the windmill has not been tested during optimal wind speed conditions. The tests that have been performed during the circumstances at the time showed that the performance of the windmill is consistent with the theoretical calculations. A proposed design for a simple drip irrigation system has been developed based on the conditions at the project area. It is constructed of plastic pipes with holes that emit water. Covers are in place to prevent soil from clogging the holes. Building the irrigation system was not part of this project.