Determination of power efficiency of locally fabricated wind turbine generators in Tanzania

The study intended to determine power efficiency of locally fabricated wind turbine permanent magnet alternative current generators in Tanzania. This was considered after noted poor performance of wind turbine generators locally developed in Tanzania. The study also compared efficiencies of locally fabricated wind turbine generator with proven equivalent wind turbine generators from the market. Parameters of locally developed wind turbine generators were optimised for improved power output efficiency using Maxwell software. The rationale for optimisation of generator parameters was to improve performance of locally fabricated wind energy generators for further investment in wind energy systems for the purpose of electricity generation especially for off-grid population in Tanzania. The study used laboratory experiment at Chalmers University of Technology Sweden to investigate characteristics of two generators with close related parameters characteristics. Three types of generators were designed. The first with 8 pole pairs, the second with 6 pole pairs and the third with 4 pole pairs and all were optimised. Efficiencies of the optimised PM generators were found to be 91.66 percent, 91.97 percent and 90.63 percent at 350 rpm for 8, 6 and 4 pole pairs, respectively. The study showed that, the best design of wind turbine PM generator is one with 6 pole pairs, which is recommended for low wind zone applications. It can be concluded from the study that, the Tanzanian locally fabricated PM generator recorded efficiency of 55 percent at 350 revolutions per minute (rpm). The equivalent standard PM generator recorded the efficiency of 96 percent at 350 rpm.