Generator bekerja dengan optimal saat sistem penggerak mengirimkan daya turbin dengan arah putaran dan kecepatan yang sesuai. Tegangan bending dan tegangan kontak pada roda gigi serta tegangan geser pada poros perlu diperhatikan dalam merancang transmisi roda gigi karena sering menyebabkan terjadi kegagalan. Dibandingkan dengan analisa teoritik, menganalisa tegangan pada desain transmisi roda gigi dengan simulasi numerik akan memberikan keterengan lebih akurat dengan hasil tidak tidak jauh berbeda. Tujuan penelitian ini menganalisa tegangan bending dan tegangan kontak pada roda gigi serta tegangan geser pada poros bertingkat menggunakan metode silumasi numerik menggunakan perangkat lunak Ansys Workbench 14,5. Desain transmisi menggunakan dua pasang roda gigi dengan tiga poros yang menerima beban 1200 Nmm pada poros pertama, 706 Nmm poros kedua, dan 456 Nmm poros ketiga. Hasil dari penelitian ini menunjukkan tegangan bending terbesar terjadi pada akar gigi, tegangan kontak terbesar terjadi pada pitch line, sedangkan tegangan geser pada poros bertingkat terjadi pada diameter terkecil. Berdasarkan nilai keamanan, desain transmisi roda gigi yang dianalisa layak digunakan.

Pelton turbine is an engine that facilitates continuous power as a wheel or a rotor continually turns due to the pressure of fast moving water through the bucket, where a bucket receives water from the surging nozzle. The objective of this research is to investigate the highest efficiency among different types of Pelton turbine through the modification of bucket volume, bucket angle attack, nozzle needle seat ring, and nozzle needle tip. The experiment was conducted at Energy Conversion Laboratory of Sebelas Maret University. The comparative study among the different parameters shows that the value of maximum efficiency was 21.65%, which was obtained at 90° needle seat ring and 45° needle tip, and +15% bucket size and 92° angle of attack. It was gained likely due to the lightness of the +15% bucket compared to the standard bucket and the collision produced by the jet water in the middle of the bucket, in which the water loading occupied the large area on the surface of the bucket and promoted the increasing speed. It is expected that the result on the appropriate size and angle attack of bucket at specific nozzle seat ring and nozzle tip of this experiment can be manufactured commercially in the future for achieving maximum Pelton turbine efficiency.

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Hydroelectric power plants (hydropower) with a power generated capacity of less than 5 kW called "Pico Hydro" (hydropower-PH). Pico Hydro is one of the renewable energy sources that are environmentally friendly. In this study aims to: (1) the manufacture hydropower plants Pico Hydro energy-efficient, renewable and environmentally friendly; (2) determine the efficiency of the turbine with the testing of flow variation; (3) determine the efficiency of generator. Designing and making portable water turbines are easily in the manufacture, operation, and maintenance and has a high efficiency and effectiveness that can use the method of reverse engineering. The production process is performed to create a turbine by the lathe and welding processes. While the materials used are mild steel. Results of this study were found that: (1) the manufacturing process of hydropower plants Pico Hydro can be performed easily by the public; (2) the type of turbine used in hydropower-PH testing is a propeller turbine with 4 blades; (3) flow measurement with V-Notch method showed the following actual debit are 5.38 x10-3 (m3/s), 6.62 x10-3 (m3/s), 7.69 x10-3 (m3/s) and 8.84 x10-3 (m3/s. Turbine efficiency is 3.59 %, 4.26 %, 5.66 % and 7.54 %. The efficiency of the generator has a value of 39.31 %, 40.51 %, 32.55 % and 30.45 %.

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