Analysis Of Energy Use On The Computer And Design Of Supply Using Solar Power For Remote Schools Abdul Muis Mappalotteng 1 Abstract - Most of the computer users may not be aware, that opens up more application programs will increase the electrical energy consumption for the computer. One side of the many users who behave thus, on the other hand there are still many users who cannot enjoy the energy. This is because there are many remote areas that have not drained electrical energy. For this school its own of problems. They cannot use the computer in administrative activities and learning in schools, This paper aims to analyze the use of energy at the time of running the application programs, and designing a solar power plant, for the purposes of the power supply for a computer at a remote school. The analysis is based on the energy usage of hardware and software that operate. The hardware used and the software that operate these greatly affect energy needs. The results showed that the use of the hardware that is too much, and operate the software greatly affect energy usage. Another finding is the amount of power needed to run the PC with CRT monitor is 279 Watt. With that much power, needed for 5 x 100 Wp solar panels, batteries 2 x 100Ah and inverter 1000 Watts. Keywords - Energy, Computer hardware and software, solar power. I. INTRODUCTION The computer is one of the electronic devices, which can work if given electrical energy. Son said that the Information Technology (IT) needs to be powered electrical energy [1]. The use and utilization of IT tools by the community resulting in increased demand in the use of electrical energy. One of the considerations in finding the IT devices, such as computers is performance. People do not realize that with the high performance, resulting in the use of electrical energy as 1 Lecturer in Education of Information and Computer Engineering, Department of Electrical Engineering Education, Faculty of Engineering (Cp: 0811418101, email: abdulmuism@gmail.com) well. Power consumption is a large unfavorable impact for the user. Users need to spend a large part of the energy it uses. According to the Son, is the energy used is wasted and not fully utilized [1]. This resulted in futility in energy use. On the other hand many people in remote areas who do not yet enjoy the energy. Especially in the electrical energy supply by PLN. Based on the ratio of national electricity, electricity condition in Indonesia is still felt not to meet the principles of justice and equity. This is understandable because of the availability of electricity from time to time is always smaller than the growing need. In addition, other constraints are seemingly still set on the status of management of electricity as a basic infrastructure (such as public infrastructure like-roads, bridges, ports, etc.) or the status of electricity as a commodity [2]. Several initiatives have been proposed, one option is to specify that the power plants that use natural resources to recover or renewable (without particular fuel), should be treated as a basic infrastructure for the community, while the power plant is built on islands and major cities established and quality should be established as a commodity. Electrification ratio in Indonesia until 2009 reportedly reached an average of 66%, but in Eastern Indonesia region has not reached 45% [2]. The level of use of electricity for the people who commonly expressed in per capita electricity consumption, also was still far from adequate. For comparison, the data of 2005's in the United States with a Gross Domestic Product (GDP) in the community an average of about US $ 35 000, - per year it reached 10,000 kwh of electricity consumption; The European Union with an average GDP of US $ 18,800 communities, - electricity consumption is about 5,700 kwh; Singapore and Malaysia with an average GDP communities above US $ 6000, - electricity consumption is about 3,000 kwh; while in Indonesia, if divided by the average population of only 500 kwh, even this with a note that in fact the people who already enjoy this quality power only around 65% of Indonesia's population.
Unequal distribution of electric energy utilities, the impact on the schools that cannot take advantage of IT devices, especially computers. They have not been able to enjoy the full potential of electricity, especially that supplied by PLN. The best way to cope with the demand for electricity in remote areas is to utilize the natural resources, such as wind power, water power, or solar power. The latter sources are available everywhere, but not every time can be utilized. Wind power or hydropower, is only available in certain areas only. Therefore, in this study, computer power supply design using solar energy, with consideration of solar light available everywhere. Indonesia is one country that has the resources in sufficient quantities solar energy abundant. Management of energy resources appropriately in turn will improve the welfare of society in general. Location of Indonesia that is at the equator is at latitude 6-11 N latitude and 95 E - 141 E, and having regard to the circulation of the sun in a year in the region of 23.50 N and 23.50 LS then Indonesia will be always exposed to the sun for 10-12 hours a day [7]. Due to the location of Indonesia is at the equator, Indonesia has a solar radiation level is very high. According to the measurement from the center of the Meteorology and Geophysics Agency estimated the radiation falling on the surface of the Earth Indonesia (especially in Eastern Indonesia) on average approximately 5.1 kwh / m2 day the monthly variation of about 9%. Since the last few years, researchers began to change his opinion on the use of existing energy sources in Indonesia. Reference is used as the basis for calculating the energy needs of the power computer is the hardware used and the power used by the software during the exercise. II. LITERATURE A. Solar Panels Photovoltaics (PV) is a module that directly convert solar light into electric current [5]. Certain materials, such as silicon, naturally release electrons when they are exposed to light, and these electrons can then be used to generate electric current. PV panels produce direct current (DC), which must be converted to AC current (Alternating Current), An inverter is used to convert DC power into AC power to run household appliances are generally standard voltage of 220 Volts. The amount of electricity produced by the inverter is measured in watts (W). The operation of the solar cell is highly dependent on [8]: a. Ambient water temperature b. Solar radiation (insulation) c. Speed wind blowing d. The state of the earth's atmosphere e. Orientation panels or PV array f. Position where the solar cell (array) to the sun (tilt angle) B. Controller Equipment Controller serves to protect the battery from charging and excessive use (discharging) the battery resulting in excessive battery quickly broken. To protect the battery so that is not easily damaged controller disconnects between solar modules and batteries before the batteries reach the stage of evaporation of water batteries (casing) which indicates a full battery and when the battery is almost empty water batteries which will change the nature of sulfuric acid into the water, controller disconnects the battery to the load (light). The selection is determined by the capacity of Controller Nominal Voltage and current Input / Output openness. Battery Control Unit (BCU) usually called the Controller or the regulator [8]. The controller serves to protect the battery from charging too full or exceed the capacity of the battery and protects the battery from excessive consumption or capacity of the battery becomes discharged. Controllers must break the link between the load and the battery before it runs out of battery capacity. Making Controller in order to function properly depending on the design of the manufacturer. Controller input current is the minimum amount of current coming from the solar module to the controller. In general, the planning controller has a maximum limit of allowable input current. For example, for charging stations 50WP Solar modules produce a short circuit current ± 25 A so that the controller is 30 A, so that the safety controller C. Battery Battery on a more appropriate centralized solar power plants system serves as electrical energy storage chemical in the day and serves as a power supply at night. The battery consists of a number of electronic cells and will produce an electric current when a load between the two electrodes. D. Inverter The inverter has a function to convert the DC voltage of the panel and a battery into AC voltage which can be used to supply the computer. By users who previously channeled through the distribution network before it gets to the house residents.
E. Computer Power Supplies Fakhar (2012) in the journal entitled "Level Green Computing Software For Large Scale Systems", concluded that the optimization of the energy savings can be seen in terms of hardware and software. Energy optimization in terms of hardware implementation of a process derived from a smaller silicon geometries, detection auto idle, and active well biasing techniques. In terms of the software implemented in the operating system by analyzing the techniques that are currently active process energy requirements [6]. Energy can also be saved by developing software that do the analysis and make the design. Saving energy use of an optimization software on the computer can produce. To calculate the power requirements on the computer, the author cites the use of the computer power of the research that has done by Ananda [3]. The results of the research that has been done shows the average electrical energy consumption to 10 units of computers using a CRT monitor is at 2790 Watt and 1854 Watt with computers using the LCD monitor. When averaged for a single unit of a computer with LCD monitor means for 185.4 Watt, and 279 Watt for computers using CRT monitors. For efficient use of energy, running application programs affects the energy consumption by a computer. Results of research conducted by Crown [1], find the amount of electricity savings when using certain software applications, and running one application at a time only. The savings that can be made for 53.6%. This needs to be considered in designing a solar power plant for the computer rationing. Furthermore, from measurements taken, a portable computer (laptop), requires power 65Watt. If the computer is being used, the specification required a smaller device. III. DISCUSSION A. Calculation of solar power plants To get solar power resources are reliable, careful analysis of the needs of the plant equipment is needed. This analysis is based on the installed capacity of the panel, taking into account the power requirements of computer to be used. 1. Need Solar Panels There are basically two ways to calculate the need for solar panels, the first by knowing in advance how much load to be connected to solar power, the second is to first determine the power of solar panels that will be used. In this design, the solar panels to be used with a capacity of 100 Watts Peak (WP). Time effective solar radiation in a day is 5 hours. Thus the solar panel is capable of supplying electrical energy at 100x5 hours = 500 Watt hours. The solar panels used are capable of producing a maximum power of 100 WP, with the maximum power voltage of 17.4 volts, the current at the maximum power of 5.76 amperes, has a short circuit current of 6.28 amperes, and the open-circuit voltage by 21.4 Volt. 2. Load Power After knowing the capacity of the solar panels are installed, the next step is to determine the maximum power that can be used load. From the amount of power generated solar panels can know how much power the maximum amount of usable load [4]. The solar panels installed can produce a maximum power of 500 watts for 5 hours of solar radiation. SPP is designed to supply 100% of the overall energy. Because losses (losses) are considered 15%, so that the energy supplied by the solar load is capable of [4]: EB = EP - system lossess = EP - (15% x EP) Watt hours = 500 - (15% x 500 Watt hours) = 425 Watt hours Remarks: EB = energy load (Watt hours) EP = Energy solar panels (Watt hours) So the total energy of the system that can be used for 425 Watt hours. 3. Need Batteries To calculate the battery needs (as a store of energy if there is no solar light), then do the conversion of energy (Watt hours) to ampere hour capacity of the battery in accordance with the unit. So the battery capacity can be calculated: The unit to store and transfer energy to the load is one day, so the battery only store energy and distribute it on the same day. The magnitude of the deep of discharge (DOD) of the battery is 80% [4]. The capacity of the batteries required are:
Based on the calculation above, it takes a battery with a minimum capacity of 44.2 Ah. Battery capacity is not found in the market, therefore the capacity of the battery used in it, for example, 50 Ah 12 Volt or 12 Volt 65 Ah. The bigger the selected battery capacity, increase the reliability of the system. If you select a battery with a capacity of 50 Ah closest that the battery can only store energy for 50Ah x 12V = 600 Watt hours. If it is used to supply a load of 425 watts, the battery is able to serve the electricity for 600Watt hours / 425Watt = 1.41 hours (1 hour and 24.6 minutes). But if you use the battery with 65Ah capacity battery can store power for 65Ah x 12V = 780 Watt hours. If it is used to supply the load for 425 Watt hours able to serve the electricity for 780 Watt hours / 425Watt hours = 1.83 hours (1 hour and 49.8 minutes). The maximum amount of electric power is not all used by electrical equipment due to approximately 20% will be used to operate the inverter [4], so that the electrical energy from the battery thatt can be used by a computer is equal to 780 - (20% x 780) = 624 Watt hours. 4. The need for Solar Charge Controller To set the battery charging from solar panels, it takes a piece of equipment called a solar charge controller (SCC), or often called battery Control Regulator (BCR). To determine how the capacity of the BCR is required, it should be calculated taking into account the maximum capacity of Solar Panels divided by the charging voltage. Thus it takes a BCR of 4.67 or higher fit on the market. In this case, use the BCR 10A, because the BCR is the lowest in the market. 5. Needs Inverter Specifications inverter must be in accordance with the working voltage of the system and the voltage at the AC load. Based on the system voltage input voltage of 12 VDC inverter. The output voltage of the inverter connected to the load is 220 VAC. Another thing to note is the ability to use the power of the inverter. If the load is only 425 watts, it can be used with a power inverter 500 Watt or greater. B. Analysis of Computer Power requirements As already described in the previous section, that a set of computer with a CRT monitor requires a 279 Watt power, and for the use of the LCD screen of 185.4 Watts. In the case of use is also a printer with power 55 Watt. Thus a minimum of 334 Watt power needed. If the average daily use for 6 hours, then the energy required in a day of: W = 334 Watts x 6 Hours W = 2004 Watt hour From the previous discussion, one of 100 Wp solar panels, capable of supplying 425 watt hour, thus to the use of energy in 2004 watt hour, it takes solar panels of 100 Wp as: Rounded to 5 solar panels (100 Wp). Battery required can be calculated using the equations that have been presented in the above discussion, the Thus it takes a battery of 12 V DC, with a minimum capacity of 167 Ah, 200 Ah can be used or the fruits (as there is in the market of 100 Ah x 2). Assuming using a 12V battery, 200Ah, then the maximum energy that can be supplied by this plant by 2400 Watt hours. Greater energy can improve the reliability of the system. If the calculated for 2 days of continuous overcast, so the sun is not enough to fill the solar system, the devices required above must be multiplied by 2 times. Based on the above analysis, to be able to turn on a PC computer with a CRT monitor and a printer with a 55 Watt power for 6 hours continuously, it takes 5 solar panels of 100 Wp, 2 pieces battery 12V, 100Ah, BCR 30 A, and a minimum of 1000 Watt Inverter. If this energy is used to distribute a laptop with a 65 Watt power, then the usage time can be calculated: Thus a laptop, it can be operated for 30 hours continuously using this system. IV. CONCLUSION Based on the analysis conducted above, it can be concluded that the energy consumption of a computer depends on the hardware it uses, especially the type of monitor. CRT consumes less power than the LCD. The use of software, and the many applications that are run affects the amount of electrical energy used. Solar power can be used for computer power supply isolated schools are not reached by the electricity. To be
able to run a PC computer with a CRT monitor and a printer with a 55 Watt power for 6 hours continuously, it takes 5 solar panels of 100 Wp, 2 pieces battery 12V, 100Ah, BCR 30 A, and at least 1000 Watt Inverter. REFERENCES [1] Putra, D., Argogalih, Setijaningsih. (2000). Analisis green Software pada Jawa Pos. Jakarta: Binus University. [2] Subaktian Lubis. 2011. http://www.esdm.go.id/ berita/323-energi-baru-danterbarukan/4310- pembangkit-listrik-tenaga-arus-laut-bagi-desa- pesisir-tertinggal-secondopinion.html?tmpl=component&print=1&page= [3] Ananda, S.A dan Putro,I.H. (200x) Studi Penggunaan energy pada monitor CRT dan LCD. Artikel pada Petra.ac.id. http://fportfolio. petra.ac.id/user_files/03-002/paper%20sntm- KE17-Stephanus-Petra.pdf [4] Armand. 2011. http://armand10dma.blogspot.com/ 2011/08/perhitungan-kebutuhan-plts.html [5] Solarsuryaindonesia. 2012. http://solarsurya- indonesia.com/panduan/menentukankebutuhan- listrik-cadangan 21 November, 2012 [6] Fakhar, F., Javed, B., Rasool, R. u., Malik, O., & Zulfiqar, K. (2012). Software Level Green Computing For Large Scale Systems. [7] Gdmenergy. 2014. http://www.gdmenergy.com/ artikel-ebt/32-potensi-pemanfaatan-solarcell-di- indonesia-mengunakan-alikasi-plts-terpusat.html. Diterbitkan: 07 April 2014 [8] Gdmenergy. 2014. http://www.gdmenergy.com/ artikel-ebt/31-teknik-dasar-pembangkitlistrik- tenaga-surya.html. Diterbitkan: 07 April 2014 [9] http://digilib.its.ac.id/public/its-undergraduate- 16580-2208100632-chapter1pdf.pdf [10] Philip M. Parker. 2007. Photovoltaic (PV) Solar Energy Equipment in Mexico: A Strategic Reference. Singapore: Insead [11] Green, M.A. 2006. Third Generation Photovoltaics: Advanced Solar Energy Conversion. New York: Springer [12] Kalogirou, Soteris. 2009. Solar energy engineering: processes and systems. London: Elsevier Abdul Muis Mappalotteng, born in Ujung Pandang, dated October 18, 1969, completed elementary school in 1982, SMP Jongaya 1985, STM Negeri 1 Ujung Pandang 1988, Department of Electrical Engineering
Education 1993, Masters of Education study program Technology and Vocational Education Teachers' Training College PPs Yogyakarta (1997), Master of Engineering, Electrical Engineering and Computer Information Systems concentration PPs UGM (2000), Doctor of Technology Education courses and Vocational PPs Yogyakarta Yogyakarta State University in 2011. In 1994 and now is a lecturer at the Faculty of Engineering, UNM, education courses S1 electrical engineering, informatics and computer engineering education S1, and S2 technology education and vocational PPs UNM Makassar. He served as chairman of the FT UNM computer lab, Head of Study Program (S1) Electrical education engineering and is currently Head of Study Program (S2) Technology and Vocational Education Graduate Program, State University of Makassar.