Design of a Vertical Axis Wind Turbine at Istanbul Beach, Tambakbulusan Village, Demak-Indonesia For Wind Generation System as an Alternative Energy Source

Limited electrical energy and high dependence on fossil fuels make the government have to be responsive to find solutions to these problems by looking for other resources. Wind power is one of the alternative energies that can be used as a power plant with wind turbine media, to overcome the above problems, the idea arose to make a vertical axis wind turbine. vertical-axis wind turbines (VAWT) are not widespread, but their simplicity and better performance in disturbed flow-fields, compared to small horizontal-axis wind turbines (HAWT) make them a good alternative for distributed generation devices in an urban environment. Istanbul Beach has wind speeds ranging from 3 m/s to 5.4 m/s which is suitable for use as a wind turbine drive. This research focuses on designing wind turbines as generator drives to get large electrical power with the best system efficiency. This study aims to design a vertical axis wind turbine and calculate the efficiency of a vertical axis wind turbine at Istambul Beach, Tambakbulusan Demak Village-Indonesia. The results of the design of a cross-flow type wind turbine for the planned power to be generated by 100 watts on the assumption that the strongest wind speed is 5.4 m/s obtained a blade specification of 8 pieces with a height of 0.75 m and a diameter of 0.19 m and a sweep area of 1.79 m2. Wind speeds at 09.00 a.m, 11.00 a.m, 01.00 p.m, 03.00 p.m, and 05.00 p.m range from 3 m/s to 6 m/s with a potential wind power of 28.9 watts to 231.9 watts resulting in a theoretical output power of 8.7 watts to 61.9 watts with fairly stable turbine efficiency at a percentage of 26% to 30%. The real power generated by the generator ranges from 0 watts to 2 watts with a system efficiency of 0% to 0.9%. Wind speeds at 09:00 a.m and 11:00 a.m ranging from 3 m/s to 4.3 m/s produce 0 watts of generator power. Wind speeds at 01:00 p.m, 03.00 p.m, and 05.00 p.m ranging from 4.4 m/s to 6 m/s produce generator power of 0.27 watts to 2 watts, The low generator power is caused by improper generator selection and the rotation of the wind turbine has not been able to meet the needs of rotation of the generator or generator speeds in rotation per minute (rpm) so that the real generator power results are difference from the output power in theory.