Traceability of pitch angle position for small scale wind turbine to get a maximum Energy Extraction

Global crisis in financial, energy, together with climate and enviromental, has motivated word community to seek for alternative energy resourses, known as the new and renewable energy source to replace conventional widely used fossil energy. Wind energy, regarded as potential candidate of the clean alternative source that may help to solve the crisis. The development of the world’s wind turbine instalation in 2010 reached 30 %, with a total capacity of 160 GW. The comprise of USA=39 GW, Germany and China = 26 GW, followed by Spain, India, Italy, etc. Indonesia as a tropical country with low wind speeds (3-6 ms) is also participate in the development. In 2008 there are 1.2 MW wind turbine instalations, and in 2011 a new plant is built in Bulukumba-South Sulawesi and Aceh, each with 0,5 MW and 10 MW, respectively. However, the majority of the installed turbines technology come from other countries, which are not fully suited with local conditions and the exist a great problem in dependency of the spare parts from the producers. Therefore, it needs to develop our own local wind turbines technology, with the key players from LAPAN,BPPT, state and private Universities in Indonesia. This paper reports development and test of a prototype for wind turbine with blade diameter of 2 m, with three blades of airfoil NREL S83n. Crucial problem in implementation of small scale wind turbine for low wind speed regimes ( i.e. 3-6 ms, like in most areas in Indonesia), is to determine the position of pitch angle of turbine blade. The right position of blades’ pitch angle may produce maximum mechanical power, wich means also maximum electrical energy. The proof of concept experiments were done by considering pre-determined dimension, type and diameter of blade, as well a range of angular velocity and power produced. The prototype of turbine was exposed to variation of wind speed flow, and stepwise variation of blades’s pitch angle was set through PC, with angular step of 5 for range of angle 0-90 degrees. Optimal pitch angle 0f 15± 5 degree was obtain, with a maximum value of Cp=0.54 Keyword : Pitch angle, wind turbine, mechanical energy, Electrical power.