In recent years, Wind power generation in Indonesia is no longer a new issue. Indonesia has average velocity from 2 m/s  to 7 m/s. With the characteristic it, Indonesia is suitable for small (10 kW) and medium wind turbine installation (10-100 kW. Based on the monitoring data from meteorological, climatological, and geophysical agency (BMKG), the average wind velocity in Bali is 2 m/s – 5m/s, hence Bali has potential to development and utilization the source for wind turbine installation, There are four stations of BMKG in Bali, which each station is supervise the region. Weibull distribution has been represented on this research to calculate and determine the probability of the each of region to know the availibility of the source. Literally,  Jembrana station has the lowest availability of power available from the district and cities in Bali, with 0-0.2 W/m2, compared with some districts and cities in Bali, with wind density power between 0-2.88 W/m2 and also the KHK station has the highest probabiity of wind velocity than the other regions. Reconstruction design had been done, with basic data from probability in Bali. The result shows that the redesign of wind turbine give an effective power to extract the wind source.

Due to its high energy concentration, hydrokinetic energy from tidal and rivers flow provides great expectation. One of the effective ways to meet the energy production target is to reduce the installation and maintenance effort arranging turbines in such configuration, known as hydrokinetic turbine array. The performance of array configuration is affected by turbine position and rotational direction. This research provides a comprehensive analysis of the effect of turbine rotational direction and position on the array performance. The experimental study and URANS simulation were carried out to gain deeper information. This previous study proposed 3 side-by-side configurations, i.e. Co-rotating” (Co), “counter-rotating-in” (CtI) and “counter-rotating-out” (CtO) and the current study proposed 2 multi-row configurations, i.e. 3T-A and 3T-B. The comprehensive information is provided. Both experimental and numerical study confirmed that the velocity superposition in the interaction zone gives the constructive effect on turbine performance. All site-by-site configurations is able to enhance farm effectiveness. Co configuration is recommended to install in the resource having unpredictable flow direction. However, the CtI is for canal or river since it has better performance. The study for multi-row configuration shows that the downstream turbine has performance decrement due to the bad effect of the upstream turbine wake.

HAWT with three blades often used because it has the highest coefficient of performance among other turbines. The airfoil used is Clark-Y type because it has a high glide ratio (coefficient lift/coefficient drag) in the application of subsonic flow. The main purpose of this study is to increase the power coefficient value obtained by the increase of lift force on each airfoil of blade compiler and to fix the wind turbine performance. One of the variations added is the addition of winglets on the tip of the blade. The method employed is a laboratory scaled experiment by using wind tunnel. Theoretically, this study also applied blade element momentum (BEM) as the calculation of each segment on the airfoil, and the simulation was carried out with computational fluid dynamics (CFD), in order to find out the characteristics of flow passing by the rotor. The advantage of using winglets is, fostering the condition of starting wind turbine rotor on low tip speed ratio (TSR) condition by varying the pitch angle on the blade. The addition of pitch variation gives an advantage that it can maximize the wind speed towards the angle of attack to the airfoil; hence, it increases the aerodynamic effect on the rotor.

Abstract. Over 70 000 000 people in Indonesia have no access to electricity. This study was carried out in Bawean Islands which are located in the Java Sea about 150 km North of Surabaya, the headquarters of East Java. The study to determine the energy services available in the Bawean Island was done through interviewing a random sample of 72 households in two villages namely Komalasa and Lebak. Based on the average monthly electricity consumption of the sampled households connected to the grid, a hybrid renewable energy based electrical supply system was designed for Gili Timur Island, one of the satellite islands around Bawean Island. The system was designed with the aid of a time step simulation software used to design and analyze hybrid power systems. A sensitivity analysis was also carried out on the optimum system to study the effects of variation in some of the system variables. HOMER suggests that for the expected peak load of 131 kW, an optimum system will consist of 150 kW from PV array, two wind turbines each rated 10 kW, a 75 kW diesel generator and batteries for storage.

No abstract