Experimental Study of The Alternative Analysis of Cross-Section Variety of Half-Circle, Bowl and Isosceles Triangle to Generate Electricity: A Case Study of Pico Hydro-Pelton Turbines in ITATS Surabaya

One of the main urgencies of a developing country such as Indonesia is developing energy supply. Under the government regulation, Indonesia thrives the supply of electricity which mainly maintain by fossil fuels such as oil, gas and coal. This energy supply is limited from time to time. To alternate the condition, environment-friendly energy sources need to be developed. One such energy source is Pico hydro with the use of the concept of a hydroelectric power generator. As we know, this type of generator proven only useful in small, remote communities balanced with a small amount of electricity and considerably function with the Pelton turbines. This study focuses to maximize the valve opening of Pelton turbines to give a good distribution system to generate the electricity. The variety of valve opening of 18⁰, 36⁰, 54⁰, 72⁰ and 90⁰ are matched to the variety of cross-section of the half-circle, bowl and Isosceles Triangle. The result of this research is that the greater the valve opening the greater the efficiency system. Type of bowl blade results in greater efficiency of the system than the semicircular and isosceles triangular blade.


INTRODUCTION
Indonesia is well-known with a great archipelago island living with 270 million people, emerging as a middle-income country under the condition of development in economic, industrialization as well as urbanization.
This development is interrelated to the demand for energy supply, in particular mixed with the enormous population.In fact, the government continued support to provide a green sustainable energy supply, but the factor of efficiency still become a burden especially in the remote area.Pico hydro come with the solution of the hydroelectric power proven to be allocated in a small, remote area that can maximize the function of use electricity.Pico-hydro setups are also practiced running by streaming with a small weir, pipes, Pelton-turbine valve and some common supported tools.In addition, typical like other hydroelectric and green source power generation, consumption of fossil fuels is maximally reduced.Some advantages of this system not limited to: (1) Utilizing zero pollutants, mainly used water as the parameter energy with a very low head system between 1 to 3 meters with a large electrical energy that has produced to turned on a laptop" has been conducted by [6].
Variations of valve openings are 18 0 ,36 0 ,54 0 ,72 0 dan 90 0 .The results showed that the duration of charging the laptop to 100% from the initial 0% condition takes about 138 minutes or 2 hours 18 minutes.
A study on the effect of the number of nozzles on the Pelton turbine.Tests were carried out with 3 variations of pressure (head), i.e., 2 kg/cm 2 , 2,5 kg/cm 2 dan 3 kg/cm 2 [7].From the test results, it is found that with 1 nozzle the efficiency is higher, where at the head of 30 m.If using 1 nozzle the output power is 9.51 Watt, while if using 2 nozzles the output power is 9.41 Watt.
Research on the performance analysis of the Pelton turbine-type hydropower system with variations in valve openings and lamp loads using an inverter was carried out [8][9].
The turbine used in this study was a Pelton valve openings with a 9 Watt lamp load, the highest power was obtained at 1.765 Watt.
The Pelton turbine prototype as alternative energy for micro-hydro in Lampung [10].The research variation is to use a variation of the discharge with the following amounts of discharge0,00043 m 3 /sec, 0,00046 m 3 /sec dan 0,0005 m 3 /sec.
In this study, the highest power was obtained at a discharge of 0.0005 m 3 /sec with a value      Therefore, the speed for doing work is also getting bigger.This is according to the mechanical power formula.
Where: P (t) = mechanical power, T = torque and ω = rpm converted to rad / s.In the graph, it can be seen that the blade with the spoon type produces a greater mechanical power than the isosceles triangle blade and the semi-circular blade.
pelton turbines that can be used to generate electrical energy have been carried out by researchers abroad, including [2][3][4][5].Pico hydro is a power plant that uses water as the driving force of the blade in the turbine which will drive the generator to produce electrical energy.In principle, Pico hydro is utilizing the flow rate of water which functions to drive the turbine that connects to the generator.Several studies on Pelton turbines can produce electrical energy by previous researchers.Research on "Experimental study of variation of the effect of the Pelton turbine valve opening on turbine with an inverter.Comparison of various lamp power, such as 3, 5, 9 and 12 Watt was analyzed.The results showed that the greater the valve opening, the greater the Volume 6, Number 1, May 2021 ISSN 2528-2611, e-ISSN 2528-2700 electric power produced, for example, 90 0

of 4 .
97 Watt for blade 40.The highest efficiency was at a discharge of 0.0005 m 3 /sec with a value of 49% at blade 40.However, from this previous research, research on variations in the shape of Pelton turbine blades on the electric power generated in water installations at ITATS has never been done before.The contribution of this research is as a database for researchers on the importance of the influence of the blade shape on the productivity of supplying electrical energy.RESEARCH METHOD Performance of system description as illustrated as a step as a follows: Water in the tendon with a height of 20 has potential energy.Through the pipe, the tendon is connected to the water valve so that the water flows.When water at the valve, the water has kinetic energy and when the valve is opened the water flows into the manometer.The manometer is used here as a monitor to ensure constant pressure, from the water manometer to the nozzle.The function of this nozzle is to maximize kinetic energy.From the nozzle, the water hits the turbine blade, and the turbine rotates.The turbine shaft is connected to the generator so that the generator rotates and produces electrical energy in the same direction.Electrical energy from the generator is stored by the battery before it is connected to the inverter.The function of this inverter is to change the direct current with a voltage of 12 volts and a strong current of 3 amperes into alternating current with a voltage of 220 volts (PLN electricity).Electrical energy from the inverter that is following the needs of the laptop to the laptop and can turn on the laptop.

Figure 2 .
Figure 2. The system scheme

Figure 3 .Figure 4
Figure 3. Describes the comparison of the effect of the valve opening on the rotation of the shaft

Figure 4 .Figure 5
Figure 4. Effect of valve opening on shaft rotation (rpm)

Figure 5 .
Figure 5. Relationship between valve opening and torque of different type of blade

Figure 6 .Figure 7
Figure 6.Effect of valve openings on mechanical power