<p class="Abstract">This research is a prototype design of a Pico hydropower plant. The Pico hydro laboratory scale is planned to be installed at the water outlet at the steam gas power plant (PLTGU) in Cilegon, whose water discharge has not been utilized. Pico hydro will produce green energy, which in turn can partially replace fossil energy needs. The purpose of this study was to determine the effect of water discharge and the number of blades on the power generated by Pico hydro. The method used in this research is an experimental method carried out in the laboratory, by designing and making Pico hydro prototypes, with several variations in the number of blades. The results of the manual calculation analysis show that the mass flow rate, circumferential speed, and the highest rotational speed are found in blade 6. Furthermore, the design process uses the CFD method, which produces the best energy when using 6 or 7 blades.  The stronger the water discharge, the higher the Rpm, and the stronger the electric current and the resulting voltage. The water discharge of 0.04 m³/s produces 215 Rpm, a current of 0.30 ampere, and a voltage of 2.00 volts. While the airflow rate of 0.08 m³/s produces 695 Rpm, a current of 0.70 ampere,s and a voltage of 4.30 volts. Statistical analysis also shows that the higher the Rpm value of the 6 blade turbine, the higher the power and current it produces.</p>

An excellence innovation for reducing greenhouse gases are done by developing a new water heater model for household applications. The application of the new model water heater by utilizing Parabolic Trough Concentrator with an indirect heating system uses heat transfer fluid able to improve the reliability of water heater compared to the thermosyphon model. Optimization for the new model is done by enhancing the reflector material and also heat transfer fluid. The experiment is done by applying the same standard measurement in order to set an adequate data for each model. The optimal reflector for the system to concentrating the solar power is polymer substrate as the fluid heated faster. The water-based solution with ethylene glycol 50:50 (v/v) for heat transfer fluid shows the best performance by achieving 98,2 oC for the 10th minute, and after one hour, the final temperature is 100,5 oC. By using a polymer substrate as a reflector for the Parabolic Trough Concentrator and using heat transfer fluid based on ethylene glycol water-based solution by concentrator 50:50 (v/v) shows the best performance among all sample with the fastest heating rate and the highest final temperature after the one-hour experiment. It shows this model has advantages to improve the system reliability by increasing the heating rate of the heat transfer fluid, which able to heat the water on the system faster.

Seabed particles with low shear stress limits are prone to erosion and sedimentation, affecting the balance of aquatic ecosystems. The water flow velocity triggered by the rotation of the ship's propellers can reach the seabed and exert significant pressure on elementary particles. However, by setting the propeller rotation threshold, the process of erosion and sedimentation of the seabed can be controlled. This study determines the propeller rotation threshold of the Landing Craft Tank (LCT) ship based on the water flow velocity it produces. The water flow velocity was investigated at several variations of propeller rotation (rpm) and variations of water depth using numerical and empirical approaches. Then, scale model experiments were carried out in the laboratory. Analysis based on the general standard criteria for erosion and sedimentation shows that an LCT vessel with a propeller diameter of 1.5 meters can use a propeller rotation of 25 rpm in all water depths. The propeller rotation of 75 rpm is safe if the propeller shaft distance to the seabed is at least 1Dp (Dp is the propeller's diameter). A 120 rpm propeller rotation is safe to use at a minimum distance of 1.5Dp, and a 230 rpm propeller rotation is safe for a minimum distance of 2Dp. Threshold values vary based on the particle type and the water depth. The propeller rotation threshold criteria are essential in determining the new under-keel clearance (UKC) to realize environmentally friendly ship operations.

Kondisi krisis harga minyak dunia yang terjadi sejak akhir tahun 2014 memberikan dampak yang signifikan terhadap kebijakan perusahaan minyak dan gas bumi dalam mengembangkan lapangan. Lapangan X memiliki reservoir dengan kandungan Gas Oil Ratio (GOR) yang tinggi. Hal ini mengindikasikan terdapat potensi kondensat untuk dapat diekstraksi dari gas alam sebelum gas dijual menuju konsumen. Condensate Extraction Plant dikembangkan di Lapangan X sejak tahun 2011 dengan kapasitas handling total sebesar 27,5 mmscfd. Seiring dengan penurunan produksi minyak dan gas bumi secara alamiah, diperlukan penyesuaian mode operasi sehingga aset yang dimiliki oleh Lapangan X dapat memberikan efisiensi yang lebih baik dibandingkan kondisi sebelumnya. Simulasi proses modifikasi plant dilakukan dengan 5 alternatif skenario proses yaitu Metode Mechanical Refrigeration Mode Operasi Seri dengan Media Pendingin Chilled Water, Metode Mechanical Refrigeration Mode Operasi Pararel dengan Media Pendingin Propana, Metode Mechanical Refrigeration Mode Operasi Seri dengan Media Pendingin Propana, Metode JT-Valves, dan Metode Turbo Expander. Evaluasi teknis dilakukan dengan simulasi menggunakan perangkat lunak Unisim, sedangkan analisa keekonomian dilakukan dengan metode levelized cost. Selain itu, dilakukan juga analisis sensitivitas keekonomian terhadap komponen harga gas, harga kondensat, CAPEX, dan OPEX. Berdasarkan hasil simulasi proses dan perhitungan keekonomian, empat alternatif proses skenario secara teknis dan ekonomis dapat dipilih untuk meningkatkan produksi kondensat. Alternatif proses skenario yang paling optimum adalah metode Mechanical Refrigeration dengan Media Pendingin Chilled Water. Berdasarkan perhitungan sensitivitas NPV dan IRR, parameter yang berpengaruh paling besar terhadap NPV dan IRR skenario proses tersebut adalah harga gas, OPEX dan harga kondensat sedangkan CAPEX memberikan pengaruh terkecil.