Mohammad Kholid Ridwan - Academia.edu (original) (raw)

Papers by Mohammad Kholid Ridwan

Journal of Environmental Protection, 2014

The population explosion, rapid urbanization rate and the increase in economic activities in Kath... more The population explosion, rapid urbanization rate and the increase in economic activities in Kathmandu Valley have created serious problems in various aspects, including solid waste management and energy deficiency. Despite the existence of distinct link between waste and energy, the "waste to energy" concept is still viewed as an inferior method in Nepal. The government and other concerned stakeholders pay more attention towards the development of hydropower, the major source of electricity production in Nepal. This paper intends to link between solid waste management and inadequacy in energy supply. Kathmandu Valley produces about 620 tons/day solid waste from its five municipalities. The study has shown some opportunities for Kathmandu Valley to convert its solid waste into energy. Even if only organic waste is treated, it produces energy sufficient to light more than 1000 houses in Kathmandu Valley. The quantity of waste, its heat content, the need of additional energy supply, the support from government and service users are some openings that hopefully can contribute to resolving the problems of solid waste and energy supply in Kathmandu Valley.

Menurut Undang-Undang No. 30 tahun 2009 tentang ketenagalistrikan diatur bahwa Pemerintah Daerah ... more Menurut Undang-Undang No. 30 tahun 2009 tentang ketenagalistrikan diatur bahwa Pemerintah Daerah termasuk Kabupaten/Kota memiliki wewenang dalam dalam perencanaan dan pengelolaan energi listrik daerah. Namun, perencanaan energi khususnya di bidang ketenagalistrikan yang dituangkan dalam Dokumen Rencana Umum Ketenagalistrikan Daerah (RUKD) masih bersifat makro pada tataran sektoral pengguna listrik, khususnya sektor rumah tangga. Data BPS tahun 2009 menunjukkan bahwa baik secara komposisi sektor pelanggan maupun satuan energi listrik yang terjual, sektor rumah tangga menempati urutan teratas dengan persentase masing-masing 87,99% dan 43,90% dibandingkan dengan sektor pelanggan listrik lainnya di Kota Yogyakarta. Oleh karena itu, penelitian ini akan difokuskan pada kajian kebutuhan energi listrik pada sektor rumah tangga dalam sudut pandang mikro dengan mempertimbangkan penggunaan teknologi peralatan listrik. Penelitian ini menggunakan perangkat lunak LEAP (Long-range Energy Alternati...

Building sector consumes significant amount of national energy load. Generally, in lighting secto... more Building sector consumes significant amount of national energy load. Generally, in lighting sector, a commercial building produces 20% 45% of total energy consumption needed (UNEP, 2006). In order to maximize the potential benefit of the energy load, lighting system design must consider performance factor and visual comfort. Aim of this research is to analyze the quality of lighting system by taking study case at Hotel Novotel Yogyakarta specifically in function room and lobby with three methods consist of numerical modelling based on SNI of lighting, on-site measurement, and computer simulation using DIALux. From the results, it is concluded that the average illuminance in function room by numerical calculation is 78.1 lux, by on-site measurement is 72.33 lux, and by simulation is 89 lux, while the SNI’s value quality is 300 lux. Results of average illuminance in lobby at night by numerical calculation is 49.05 lux, by on-site measurement 48.02 lux, and by simulation is 70 lux. Bas...

Building sector has been a part of the huge national energy load in order to improve the conserva... more Building sector has been a part of the huge national energy load in order to improve the conservation and energy efficiency. In lighting sector, generally a commercial building produces energy load 20% - 45% of total energy consumption needed (UNEP, 2006). With that huge energy load, lighting system must consider its performance factor and visual comfort produced. This research is to analyze the quality of lighting system at Hotel Novotel Yogyakarta in function room and lobby with three methods which are numerical modelling based on SNI of lighting, on-site measurement, and computer simulation using DiaLux. From the results of this research,it is concluded that the average illuminance in function room by numerical calculation is 78.1 lux, by on-site measurement is 72.33 lux, and by simulation is 89 lux, while the SNI�s value quality is 300 lux. Results of averege illuminance in lobby at night by numerical calculation is 49.05 lux, by on-site measurement 48.02 lux, and by simulatio...

Fokus kebijakan energi selama ini hanya memperhatikan sektor Supply Side Management (SSM), sedang... more Fokus kebijakan energi selama ini hanya memperhatikan sektor Supply Side Management (SSM), sedangkan penerapan konservasi energi Demand Side Management (DSM) belum dilakukan secara maksimal. Tujuan penelitian ini untuk mengetahui proyeksi permintaan energi listrik rumah tangga di Yogyakarta tahun 2010 hingga 2025 berdasarkan penggunaan peralatan listrik, pertumbuhan rumah tangga, serta penerapan konservasi pada peralatan listrik. Penelitian ini menggunakan metode yang disebut BUENAS (Bottom Up Energy Analysis System) dengan mengambil sampel 269 rumah tangga di Yogyakarta secara cluster random sampling. Data konsumsi peralatan listrik kemudian digunakan untuk memprediksi kebutuhan listrik kota Yogyakarta tahun 2010 hingga 2025 menggunakan perangkat lunak LEAP (Long range Energy Alternatives Planning System). Proyeksi yang dilakukan berdasarkan pendekatan end-use dan pendekatan trend dengan kecenderungan pertumbuhan jumlah rumah tangga.

Sustainability, 2021

Electricity-saving strategies are an essential solution to overcoming increasing global CO2 emiss... more Electricity-saving strategies are an essential solution to overcoming increasing global CO2 emission and electricity consumption problems; therefore, the determinant factors of electricity consumption in households need to be assessed. Most previous studies were conducted in developed countries of subtropical regions that had different household characteristic factors from those in developing countries of tropical regions. A field survey was conducted on electricity consumption for Malaysian households to investigate the factors affecting electricity consumption that focused on technology perspective (building and appliance characteristics) and socio-economic perspective (socio-demographics and occupant behaviour). To analyse the determinant factors of electricity consumption, direct and indirect questionnaire surveys were conducted from November 2017 to January 2018 among 214 university students. Direct questionnaire surveys were performed in order to obtain general information tha...

International Journal of Science, Technology & Management, 2021

The horizontal axis wind turbine (HAWT) design with low wind speed requires blade geometry select... more The horizontal axis wind turbine (HAWT) design with low wind speed requires blade geometry selection. The analysis uses the potential flow panel method and the integral boundary layer formulation to analyze wind flow around the airfoil. The blade design with the blade element momentum (BEM) theory has an aerodynamic coefficient value along the blade. Power wind calculates to model the wind shear pressure at each blade. This research aims to determine the wind turbine rotor based on the performance, including the power coefficient, tip speed ratio, power, and rpm. The simulation uses an airfoil NACA 4412 which has optimal coefficient lift (Cl) = 1.92 at 190 pitch of angle, coefficient drag (Cd) = 0.0635 at 130 pitch angle and Cl / Cd = 155 at tilt angle = 40. Five models of 2.5 m diameter blades with different angles for each chord. The test results show that the change in the speed ratio affects the power coefficient so that the optimal power coefficient on NACA 4412 in experiment 5...

JPSE (Journal of Physical Science and Engineering), 2020

In producing electrical energy, the solar module is affected by some factors, such as the solar r... more In producing electrical energy, the solar module is affected by some factors, such as the solar radiation intensity, temperature, orientation and slope of the module, and shading that occurs during operation. The solar power plant of Setjen KESDM is coordinated at 6°10'53.73" south latitude and 106°49'24.61" east longitude, with a slope of 9.7°-10.0° and azimuth of-2.0° to-5.0° towards the north. It consists of five placement locations, including 11 th floor rooftop, T1, T2, T3, and L carports with a total capacity of 150 kWp. The analysis of the production of rooftop on grid solar power plant in the government building with a case study in the Setjen KESDM was intended to determine the level of production of the solar power plant built and the parameters that influence it, which was conducted by comparing the real results with the simulation results using SAM software. The energy production in 2017 was 118,259.3 kWh, in 2018 was 106,318.3 kWh, and in 2019 was 109,973.0 kWh. The highest production was obtained in September, October, and March every year due to the maximum solar radiation. The solar power plant on the 11 th floor rooftop was more maximal in producing energy for all positions of the sun than the solar power plant on the T1, T2, T3, and L carports because it was free of shading from buildings and trees. The output produced by the solar power plant of Setjen KESDM could not reach the maximum point because the location temperature was higher than the standard test conditions of the solar module.

Journal of Approriate Technology for Community Services, 2020

Sumber daya energi yang digunakan oleh jaringan interkoneksi umumnya menggunakan energi fosil (ba... more Sumber daya energi yang digunakan oleh jaringan interkoneksi umumnya menggunakan energi fosil (batubara). Oleh karena itu kita memerlukan pengganti bahan bakar fosil di masa depan. Pemanfaatan energi terbarukan salah satunya pengoptimalan energi surya yang dapat diterapkan pada daerah perkotaan. Sektor bangunan mengkonsumsi hingga 40% dari total energi tahunan. Salah satu gedung yang dapat menerapkan pemanfaatan energi terbarukan yaitu gedung kantor Dinas PUP-ESDM D. I. Yogyakarta. Penelitian ini bertujuan untuk mengetahui potensi daya yang dihasilkan dari PLTS atap jika dibangun pada gedung Dinas Pekerjaan Umum, Perumahan dan Energi Sumber Daya Mineral (PUP-ESDM) D. I. Yogyakarta. Penelitian dilakukan dengan melakukan simulasi energi menggunakan software HelioScope. Hasil simulasi menunjukkan sisi timur gedung 1, sisi timur gedung 2, sisi timur gedung 3, sisi barat gedung 2 dan sisi utara gedung 2 merupakan lokasi optimal fotovoltaik. Total potensi energi yang dihasilkan dari kelima atap tersebut sebesar 73.484,5 kWh/tahun dan mampu menyuplai kebutuhan energi Dinas PUP-ESDM sebesar 74,42 %.

Jurnal Bakti Saintek: Jurnal Pengabdian Masyarakat Bidang Sains dan Teknologi, 2018

Jumlah santri yang mencapai 4.986 orang di ketiga Pondok Pesantren Al-Anwar menyebabkan produksi ... more Jumlah santri yang mencapai 4.986 orang di ketiga Pondok Pesantren Al-Anwar menyebabkan produksi sampah di lingkungan pondok lebih dari satu ton per harinya. Sejumlah 239,93 kg sampah merupakan sampah plastik yang tidak mudah terurai di lingkungan karena sifatnya yang nonbiodegradable. Hal ini menimbulkan pencemaran lingkungan, terlebih ketika sampah dibakar di udara terbuka dan dibuang ke laut seperti metode penanganan sampah yang dilakukan oleh pengurus pondok saat ini. Dalam penelitian ini diharapkan menjadi langkah awal pembelajaran pelestarian lingkungan dengan teknologi pirolisis. Penelitian dilakukan dengan membuat model mesin pirolisis Plastic to Oil Machine (PeTOM), berkapasitas 30 liter. Dengan mesin ini, minyak mulai dihasilkan pada menit ke-45 yang mana setiap 1 kg sampah plastik menghasilkan 0,4-0,49 kg minyak bakar. Potensi minyak bakar yang dihasilkan di Pondok Pesantren Al Anwar adalah 239,33 liter per hari dengan potensi ekonomi setara dengan Rp. 35.899.200,00 per b...

International Journal of Electrical and Computer Engineering (IJECE), 2018

The residential sector was one of the contributors to the increase in the world energy consumptio... more The residential sector was one of the contributors to the increase in the world energy consumption and CO2 emission due to the increase population, economic development, and improved living standard. Developing a reliable model of electrical energy consumption based on techno-socio economic factors was challenging since many assumptions need to be considered. Over the past decade, bottom-up approaches such as multi-linear regression, artificial neural network (ANN), and conditional demand analysis were used for developing mathematical models to investigate interrelated characteristics among techno-socio economic factors. However, the existing models mostly were focused on countries that had different socio-economic level and cultures from the developing countries of the Association of Southeast Asian Nations. Similar studies in that tropical region were very scarce and only limited for linear modelling under the conditions of techno-socio economic factors. In this study, we proposed...

2016 2nd International Conference on Science and Technology-Computer (ICST), 2016

The environmental data mapping has become an important step to measure the mitigation plans from ... more The environmental data mapping has become an important step to measure the mitigation plans from pollution impacts. It often requires an observer to measure environmental data in the field using portable measuring devices and combines them with geolocation data to produce geomapped data. One of its technical difficulties during this process is in the step of recording the data, since the observer usually has to record measurement data manually into certain program. In this paper, we developed a smartphone application that capable in reading digits on a handheld measuring device display using computer vision. The measured data is sent to a cloud-based data management system, Google Fusion Tables in order to be displayed in the form of interactive maps with web application. The template matching and pixel counting methods were used to recognize the digits of each respective digit. The variations of pre-processing techniques and template matching methods were also tested. It is shown that the combination of pixel counting and normalized correlation coefficient template matching method with binary digit and template images input resulted in maximum accuracy. From 120 sample images with varied lighting conditions, both in lab-scaled and in-field tests, the digit recognition rate has achieved 70.83% accuracy in lab-scaled and 67.92% when tested in-field. Nevertheless, digit recognition method shown unsatisfactory result which demands different digit recognition method.

Procedia Environmental Sciences, 2013

To increase share of renewable in energy mix and to increase decentralized nature of the energy s... more To increase share of renewable in energy mix and to increase decentralized nature of the energy system, Yogyakarta needs to improve energy technology applications that utilize a variety of local renewable energy resources. In this spirit, this paper describes examples that demonstrate challenges in the application of small-scale renewable energy installations based on bio-energy, hydropower and small-scale photovoltaics system in Yogyakarta. Discussion was focused on the challenges of benefit sustainability in utilizing renewable energy technologies. The study was conducted on three biodig2ester systems based on cattle waste: two systems utilizing waste from tofu small industry and a system using human faeces. From socio-cultural point of view, the study showed tendency of willingness of local community to use biogas instead of fossil-based energy and indication of the willingness of local community to run and maintain existing biodigester systems. However, there was still lack of proper operation and maintenance standard. The study showed that three cattle manure-based biodigester could reach 91%, 78% and 85% of theoretical level respectively. Two biodigester systems based on tofu industry waste achieved 72.78% and 0%, respectively, while the human faeces biodigester reached level of 95.6%. Furthermore, it was shown that six biodigester systems studied were unable to meet economic feasibility criteria. Study was also conducted on a micro-hydro power plant built in Van Der Wick irrigation channel. The power plant was of 11 kW installed capacity. The study was focused on debris being blocked by trash rack and its influence on the power plant. The result showed that the debris accumulation could lead to blockage of the trash rack that could, in turn, decrease water discharge flowing into intake of the power plant. In one observation during the study, the power plant even stopped working in less than four hours due to total trash rack blockage. Meanwhile, another set of detail study was also conducted on 20 of 60 solar home systems (SHSs) which were in operation for two years. They were distributed and installed by the government of Yogyakarta to districts of the province as a grant. The SHSs are of 50 Wp and are designed to power three lights. The study showed that all SHS under study could, in average, only achieve 68.05% of designed performance level. Besides, the problems in solar panels, wiring, inverter and light ballast were also found. The last one occurred in 50% of SHSs under study.

Procedia Environmental Sciences, 2013

Electricity consumption in airport terminal buildings can be identified via Low Voltage Main Dist... more Electricity consumption in airport terminal buildings can be identified via Low Voltage Main Distribution Panel (LVMDP) which each of them serves individual distribution block. Total electricity consumption based on distribution blocks does not describe operational characteristics of building systems. Utilization of building energy performance simulation software offers solution by providing electricity consumption data based on building systems. This research applied the method in simulating energy consumption and CO2 emission in Terminal 3 Soekarno-Hatta International Airport. Simulation result shows that total electricity consumption of Terminal 3 is 27700.107 GJ or 7.694 MWh per year, with 86.59% of that is consumed by HVAC system, 9.33% used by lighting system, 2.41% used by electricity equipment, and 1.76% consumed by transportation system. In order to achieve CO 2 emission reduction, three scenarios are simulated in this research, i.e. increasing temperature setpoint, AHU (Air Handling Unit) rescheduling, and window films replacement. Increasing temperature setpoint could reduce 247.179 ton of CO 2 emission per year. Increasing temperature combined with AHU rescheduling could reduce 286.611 ton of CO 2 emission per year. Window film replacement combined with increasing temperature setpoint and AHU rescheduling could reduce 289.966 ton of CO 2 emission per year.

Journal of Applied Meteorology and Climatology, 2009

The authors’ objective was to apply the Simple Urban Energy Balance Model for Mesoscale Simulatio... more The authors’ objective was to apply the Simple Urban Energy Balance Model for Mesoscale Simulation (SUMM) to cities. Data were selected from 1-yr flux observations conducted at three sites in two cities: one site in Kugahara, Japan (Ku), and two sites in Basel, Switzerland (U1 and U2). A simple vegetation scheme was implemented in SUMM to apply the model to vegetated cities, and the surface energy balance and radiative temperature TR were evaluated. SUMM generally reproduced seasonal and diurnal trends of surface energy balance and TR at Ku and U2, whereas relatively large errors were obtained for the daytime results of sensible heat flux QH and heat storage ΔQS at U1. Overall, daytime underestimations of QH and overestimations of ΔQS and TR were common. These errors were partly induced by the poor parameterization of the natural logarithm of the ratio of roughness length for momentum to heat (κB−1); that is, the observed κB−1 values at vegetated cities were smaller than the simulat...

Journal of Engineering and Technological Sciences, 2017

Rapid urbanization has made Kathmandu Valley one of the fastest growing metropolitan cities in So... more Rapid urbanization has made Kathmandu Valley one of the fastest growing metropolitan cities in South Asia, resulting in the need of additional facilities and infrastructure. The local energy crisis is one of the issues to be addressed. High dependence on imported fossil fuels and the sluggish development of hydropower for electricity generation despite abundant water resources are the major causes to be blamed for the energy crisis in Nepal. This study investigated possible strategies to be implemented in Kathmandu Valley to deal with the discrepancy between energy demand and supply. Several scenarios have been developed and analyzed, both quantitatively and qualitatively. The Comprehensive Scenario, which borrowed from all other developed scenarios, seems superior to the others. It reduces the energy demand by 32.36%, the GHG emission by 44.12%, and the social cost by 33.79%. This scenario implies that the Kathmandu Valley authority will support the installation of photovoltaic solar panels, the use of electric vehicles and electric cookers, and convert solid waste into energy. However, the EV Scenario (electric vehicles) is the one to be given priority in the implementation for its better performance than the other individual scenarios.

PROCEEDINGS OF HYDRAULIC ENGINEERING, 2007

This paper reports on the evaluation of Simple Urban Energy Balance for Mesoscale Simulation (SUM... more This paper reports on the evaluation of Simple Urban Energy Balance for Mesoscale Simulation (SUMM) to two cities (i.e. Kugahara, Japan; Basel, Switzerland) in winter, spring and summer. This new version of SUMM is incorporated with vegetation scheme to meet the existence of vegetation fraction in real city. SUMM simulated the urban energy balance and radiative temperature (T r) generally well in Kugahara and Basel. However, SUMM slightly underestimated T r in the nighttime and overestimated T r in the daytime in Basel.

Journal of Environmental Protection, 2014

The population explosion, rapid urbanization rate and the increase in economic activities in Kath... more The population explosion, rapid urbanization rate and the increase in economic activities in Kathmandu Valley have created serious problems in various aspects, including solid waste management and energy deficiency. Despite the existence of distinct link between waste and energy, the "waste to energy" concept is still viewed as an inferior method in Nepal. The government and other concerned stakeholders pay more attention towards the development of hydropower, the major source of electricity production in Nepal. This paper intends to link between solid waste management and inadequacy in energy supply. Kathmandu Valley produces about 620 tons/day solid waste from its five municipalities. The study has shown some opportunities for Kathmandu Valley to convert its solid waste into energy. Even if only organic waste is treated, it produces energy sufficient to light more than 1000 houses in Kathmandu Valley. The quantity of waste, its heat content, the need of additional energy supply, the support from government and service users are some openings that hopefully can contribute to resolving the problems of solid waste and energy supply in Kathmandu Valley.

Menurut Undang-Undang No. 30 tahun 2009 tentang ketenagalistrikan diatur bahwa Pemerintah Daerah ... more Menurut Undang-Undang No. 30 tahun 2009 tentang ketenagalistrikan diatur bahwa Pemerintah Daerah termasuk Kabupaten/Kota memiliki wewenang dalam dalam perencanaan dan pengelolaan energi listrik daerah. Namun, perencanaan energi khususnya di bidang ketenagalistrikan yang dituangkan dalam Dokumen Rencana Umum Ketenagalistrikan Daerah (RUKD) masih bersifat makro pada tataran sektoral pengguna listrik, khususnya sektor rumah tangga. Data BPS tahun 2009 menunjukkan bahwa baik secara komposisi sektor pelanggan maupun satuan energi listrik yang terjual, sektor rumah tangga menempati urutan teratas dengan persentase masing-masing 87,99% dan 43,90% dibandingkan dengan sektor pelanggan listrik lainnya di Kota Yogyakarta. Oleh karena itu, penelitian ini akan difokuskan pada kajian kebutuhan energi listrik pada sektor rumah tangga dalam sudut pandang mikro dengan mempertimbangkan penggunaan teknologi peralatan listrik. Penelitian ini menggunakan perangkat lunak LEAP (Long-range Energy Alternati...

Building sector consumes significant amount of national energy load. Generally, in lighting secto... more Building sector consumes significant amount of national energy load. Generally, in lighting sector, a commercial building produces 20% 45% of total energy consumption needed (UNEP, 2006). In order to maximize the potential benefit of the energy load, lighting system design must consider performance factor and visual comfort. Aim of this research is to analyze the quality of lighting system by taking study case at Hotel Novotel Yogyakarta specifically in function room and lobby with three methods consist of numerical modelling based on SNI of lighting, on-site measurement, and computer simulation using DIALux. From the results, it is concluded that the average illuminance in function room by numerical calculation is 78.1 lux, by on-site measurement is 72.33 lux, and by simulation is 89 lux, while the SNI’s value quality is 300 lux. Results of average illuminance in lobby at night by numerical calculation is 49.05 lux, by on-site measurement 48.02 lux, and by simulation is 70 lux. Bas...

Building sector has been a part of the huge national energy load in order to improve the conserva... more Building sector has been a part of the huge national energy load in order to improve the conservation and energy efficiency. In lighting sector, generally a commercial building produces energy load 20% - 45% of total energy consumption needed (UNEP, 2006). With that huge energy load, lighting system must consider its performance factor and visual comfort produced. This research is to analyze the quality of lighting system at Hotel Novotel Yogyakarta in function room and lobby with three methods which are numerical modelling based on SNI of lighting, on-site measurement, and computer simulation using DiaLux. From the results of this research,it is concluded that the average illuminance in function room by numerical calculation is 78.1 lux, by on-site measurement is 72.33 lux, and by simulation is 89 lux, while the SNI�s value quality is 300 lux. Results of averege illuminance in lobby at night by numerical calculation is 49.05 lux, by on-site measurement 48.02 lux, and by simulatio...

Fokus kebijakan energi selama ini hanya memperhatikan sektor Supply Side Management (SSM), sedang... more Fokus kebijakan energi selama ini hanya memperhatikan sektor Supply Side Management (SSM), sedangkan penerapan konservasi energi Demand Side Management (DSM) belum dilakukan secara maksimal. Tujuan penelitian ini untuk mengetahui proyeksi permintaan energi listrik rumah tangga di Yogyakarta tahun 2010 hingga 2025 berdasarkan penggunaan peralatan listrik, pertumbuhan rumah tangga, serta penerapan konservasi pada peralatan listrik. Penelitian ini menggunakan metode yang disebut BUENAS (Bottom Up Energy Analysis System) dengan mengambil sampel 269 rumah tangga di Yogyakarta secara cluster random sampling. Data konsumsi peralatan listrik kemudian digunakan untuk memprediksi kebutuhan listrik kota Yogyakarta tahun 2010 hingga 2025 menggunakan perangkat lunak LEAP (Long range Energy Alternatives Planning System). Proyeksi yang dilakukan berdasarkan pendekatan end-use dan pendekatan trend dengan kecenderungan pertumbuhan jumlah rumah tangga.

Sustainability, 2021

Electricity-saving strategies are an essential solution to overcoming increasing global CO2 emiss... more Electricity-saving strategies are an essential solution to overcoming increasing global CO2 emission and electricity consumption problems; therefore, the determinant factors of electricity consumption in households need to be assessed. Most previous studies were conducted in developed countries of subtropical regions that had different household characteristic factors from those in developing countries of tropical regions. A field survey was conducted on electricity consumption for Malaysian households to investigate the factors affecting electricity consumption that focused on technology perspective (building and appliance characteristics) and socio-economic perspective (socio-demographics and occupant behaviour). To analyse the determinant factors of electricity consumption, direct and indirect questionnaire surveys were conducted from November 2017 to January 2018 among 214 university students. Direct questionnaire surveys were performed in order to obtain general information tha...

International Journal of Science, Technology & Management, 2021

The horizontal axis wind turbine (HAWT) design with low wind speed requires blade geometry select... more The horizontal axis wind turbine (HAWT) design with low wind speed requires blade geometry selection. The analysis uses the potential flow panel method and the integral boundary layer formulation to analyze wind flow around the airfoil. The blade design with the blade element momentum (BEM) theory has an aerodynamic coefficient value along the blade. Power wind calculates to model the wind shear pressure at each blade. This research aims to determine the wind turbine rotor based on the performance, including the power coefficient, tip speed ratio, power, and rpm. The simulation uses an airfoil NACA 4412 which has optimal coefficient lift (Cl) = 1.92 at 190 pitch of angle, coefficient drag (Cd) = 0.0635 at 130 pitch angle and Cl / Cd = 155 at tilt angle = 40. Five models of 2.5 m diameter blades with different angles for each chord. The test results show that the change in the speed ratio affects the power coefficient so that the optimal power coefficient on NACA 4412 in experiment 5...

JPSE (Journal of Physical Science and Engineering), 2020

In producing electrical energy, the solar module is affected by some factors, such as the solar r... more In producing electrical energy, the solar module is affected by some factors, such as the solar radiation intensity, temperature, orientation and slope of the module, and shading that occurs during operation. The solar power plant of Setjen KESDM is coordinated at 6°10'53.73" south latitude and 106°49'24.61" east longitude, with a slope of 9.7°-10.0° and azimuth of-2.0° to-5.0° towards the north. It consists of five placement locations, including 11 th floor rooftop, T1, T2, T3, and L carports with a total capacity of 150 kWp. The analysis of the production of rooftop on grid solar power plant in the government building with a case study in the Setjen KESDM was intended to determine the level of production of the solar power plant built and the parameters that influence it, which was conducted by comparing the real results with the simulation results using SAM software. The energy production in 2017 was 118,259.3 kWh, in 2018 was 106,318.3 kWh, and in 2019 was 109,973.0 kWh. The highest production was obtained in September, October, and March every year due to the maximum solar radiation. The solar power plant on the 11 th floor rooftop was more maximal in producing energy for all positions of the sun than the solar power plant on the T1, T2, T3, and L carports because it was free of shading from buildings and trees. The output produced by the solar power plant of Setjen KESDM could not reach the maximum point because the location temperature was higher than the standard test conditions of the solar module.

Journal of Approriate Technology for Community Services, 2020

Sumber daya energi yang digunakan oleh jaringan interkoneksi umumnya menggunakan energi fosil (ba... more Sumber daya energi yang digunakan oleh jaringan interkoneksi umumnya menggunakan energi fosil (batubara). Oleh karena itu kita memerlukan pengganti bahan bakar fosil di masa depan. Pemanfaatan energi terbarukan salah satunya pengoptimalan energi surya yang dapat diterapkan pada daerah perkotaan. Sektor bangunan mengkonsumsi hingga 40% dari total energi tahunan. Salah satu gedung yang dapat menerapkan pemanfaatan energi terbarukan yaitu gedung kantor Dinas PUP-ESDM D. I. Yogyakarta. Penelitian ini bertujuan untuk mengetahui potensi daya yang dihasilkan dari PLTS atap jika dibangun pada gedung Dinas Pekerjaan Umum, Perumahan dan Energi Sumber Daya Mineral (PUP-ESDM) D. I. Yogyakarta. Penelitian dilakukan dengan melakukan simulasi energi menggunakan software HelioScope. Hasil simulasi menunjukkan sisi timur gedung 1, sisi timur gedung 2, sisi timur gedung 3, sisi barat gedung 2 dan sisi utara gedung 2 merupakan lokasi optimal fotovoltaik. Total potensi energi yang dihasilkan dari kelima atap tersebut sebesar 73.484,5 kWh/tahun dan mampu menyuplai kebutuhan energi Dinas PUP-ESDM sebesar 74,42 %.

Jurnal Bakti Saintek: Jurnal Pengabdian Masyarakat Bidang Sains dan Teknologi, 2018

Jumlah santri yang mencapai 4.986 orang di ketiga Pondok Pesantren Al-Anwar menyebabkan produksi ... more Jumlah santri yang mencapai 4.986 orang di ketiga Pondok Pesantren Al-Anwar menyebabkan produksi sampah di lingkungan pondok lebih dari satu ton per harinya. Sejumlah 239,93 kg sampah merupakan sampah plastik yang tidak mudah terurai di lingkungan karena sifatnya yang nonbiodegradable. Hal ini menimbulkan pencemaran lingkungan, terlebih ketika sampah dibakar di udara terbuka dan dibuang ke laut seperti metode penanganan sampah yang dilakukan oleh pengurus pondok saat ini. Dalam penelitian ini diharapkan menjadi langkah awal pembelajaran pelestarian lingkungan dengan teknologi pirolisis. Penelitian dilakukan dengan membuat model mesin pirolisis Plastic to Oil Machine (PeTOM), berkapasitas 30 liter. Dengan mesin ini, minyak mulai dihasilkan pada menit ke-45 yang mana setiap 1 kg sampah plastik menghasilkan 0,4-0,49 kg minyak bakar. Potensi minyak bakar yang dihasilkan di Pondok Pesantren Al Anwar adalah 239,33 liter per hari dengan potensi ekonomi setara dengan Rp. 35.899.200,00 per b...

International Journal of Electrical and Computer Engineering (IJECE), 2018

The residential sector was one of the contributors to the increase in the world energy consumptio... more The residential sector was one of the contributors to the increase in the world energy consumption and CO2 emission due to the increase population, economic development, and improved living standard. Developing a reliable model of electrical energy consumption based on techno-socio economic factors was challenging since many assumptions need to be considered. Over the past decade, bottom-up approaches such as multi-linear regression, artificial neural network (ANN), and conditional demand analysis were used for developing mathematical models to investigate interrelated characteristics among techno-socio economic factors. However, the existing models mostly were focused on countries that had different socio-economic level and cultures from the developing countries of the Association of Southeast Asian Nations. Similar studies in that tropical region were very scarce and only limited for linear modelling under the conditions of techno-socio economic factors. In this study, we proposed...

2016 2nd International Conference on Science and Technology-Computer (ICST), 2016

The environmental data mapping has become an important step to measure the mitigation plans from ... more The environmental data mapping has become an important step to measure the mitigation plans from pollution impacts. It often requires an observer to measure environmental data in the field using portable measuring devices and combines them with geolocation data to produce geomapped data. One of its technical difficulties during this process is in the step of recording the data, since the observer usually has to record measurement data manually into certain program. In this paper, we developed a smartphone application that capable in reading digits on a handheld measuring device display using computer vision. The measured data is sent to a cloud-based data management system, Google Fusion Tables in order to be displayed in the form of interactive maps with web application. The template matching and pixel counting methods were used to recognize the digits of each respective digit. The variations of pre-processing techniques and template matching methods were also tested. It is shown that the combination of pixel counting and normalized correlation coefficient template matching method with binary digit and template images input resulted in maximum accuracy. From 120 sample images with varied lighting conditions, both in lab-scaled and in-field tests, the digit recognition rate has achieved 70.83% accuracy in lab-scaled and 67.92% when tested in-field. Nevertheless, digit recognition method shown unsatisfactory result which demands different digit recognition method.

Procedia Environmental Sciences, 2013

To increase share of renewable in energy mix and to increase decentralized nature of the energy s... more To increase share of renewable in energy mix and to increase decentralized nature of the energy system, Yogyakarta needs to improve energy technology applications that utilize a variety of local renewable energy resources. In this spirit, this paper describes examples that demonstrate challenges in the application of small-scale renewable energy installations based on bio-energy, hydropower and small-scale photovoltaics system in Yogyakarta. Discussion was focused on the challenges of benefit sustainability in utilizing renewable energy technologies. The study was conducted on three biodig2ester systems based on cattle waste: two systems utilizing waste from tofu small industry and a system using human faeces. From socio-cultural point of view, the study showed tendency of willingness of local community to use biogas instead of fossil-based energy and indication of the willingness of local community to run and maintain existing biodigester systems. However, there was still lack of proper operation and maintenance standard. The study showed that three cattle manure-based biodigester could reach 91%, 78% and 85% of theoretical level respectively. Two biodigester systems based on tofu industry waste achieved 72.78% and 0%, respectively, while the human faeces biodigester reached level of 95.6%. Furthermore, it was shown that six biodigester systems studied were unable to meet economic feasibility criteria. Study was also conducted on a micro-hydro power plant built in Van Der Wick irrigation channel. The power plant was of 11 kW installed capacity. The study was focused on debris being blocked by trash rack and its influence on the power plant. The result showed that the debris accumulation could lead to blockage of the trash rack that could, in turn, decrease water discharge flowing into intake of the power plant. In one observation during the study, the power plant even stopped working in less than four hours due to total trash rack blockage. Meanwhile, another set of detail study was also conducted on 20 of 60 solar home systems (SHSs) which were in operation for two years. They were distributed and installed by the government of Yogyakarta to districts of the province as a grant. The SHSs are of 50 Wp and are designed to power three lights. The study showed that all SHS under study could, in average, only achieve 68.05% of designed performance level. Besides, the problems in solar panels, wiring, inverter and light ballast were also found. The last one occurred in 50% of SHSs under study.

Procedia Environmental Sciences, 2013

Electricity consumption in airport terminal buildings can be identified via Low Voltage Main Dist... more Electricity consumption in airport terminal buildings can be identified via Low Voltage Main Distribution Panel (LVMDP) which each of them serves individual distribution block. Total electricity consumption based on distribution blocks does not describe operational characteristics of building systems. Utilization of building energy performance simulation software offers solution by providing electricity consumption data based on building systems. This research applied the method in simulating energy consumption and CO2 emission in Terminal 3 Soekarno-Hatta International Airport. Simulation result shows that total electricity consumption of Terminal 3 is 27700.107 GJ or 7.694 MWh per year, with 86.59% of that is consumed by HVAC system, 9.33% used by lighting system, 2.41% used by electricity equipment, and 1.76% consumed by transportation system. In order to achieve CO 2 emission reduction, three scenarios are simulated in this research, i.e. increasing temperature setpoint, AHU (Air Handling Unit) rescheduling, and window films replacement. Increasing temperature setpoint could reduce 247.179 ton of CO 2 emission per year. Increasing temperature combined with AHU rescheduling could reduce 286.611 ton of CO 2 emission per year. Window film replacement combined with increasing temperature setpoint and AHU rescheduling could reduce 289.966 ton of CO 2 emission per year.

Journal of Applied Meteorology and Climatology, 2009

The authors’ objective was to apply the Simple Urban Energy Balance Model for Mesoscale Simulatio... more The authors’ objective was to apply the Simple Urban Energy Balance Model for Mesoscale Simulation (SUMM) to cities. Data were selected from 1-yr flux observations conducted at three sites in two cities: one site in Kugahara, Japan (Ku), and two sites in Basel, Switzerland (U1 and U2). A simple vegetation scheme was implemented in SUMM to apply the model to vegetated cities, and the surface energy balance and radiative temperature TR were evaluated. SUMM generally reproduced seasonal and diurnal trends of surface energy balance and TR at Ku and U2, whereas relatively large errors were obtained for the daytime results of sensible heat flux QH and heat storage ΔQS at U1. Overall, daytime underestimations of QH and overestimations of ΔQS and TR were common. These errors were partly induced by the poor parameterization of the natural logarithm of the ratio of roughness length for momentum to heat (κB−1); that is, the observed κB−1 values at vegetated cities were smaller than the simulat...

Journal of Engineering and Technological Sciences, 2017

Rapid urbanization has made Kathmandu Valley one of the fastest growing metropolitan cities in So... more Rapid urbanization has made Kathmandu Valley one of the fastest growing metropolitan cities in South Asia, resulting in the need of additional facilities and infrastructure. The local energy crisis is one of the issues to be addressed. High dependence on imported fossil fuels and the sluggish development of hydropower for electricity generation despite abundant water resources are the major causes to be blamed for the energy crisis in Nepal. This study investigated possible strategies to be implemented in Kathmandu Valley to deal with the discrepancy between energy demand and supply. Several scenarios have been developed and analyzed, both quantitatively and qualitatively. The Comprehensive Scenario, which borrowed from all other developed scenarios, seems superior to the others. It reduces the energy demand by 32.36%, the GHG emission by 44.12%, and the social cost by 33.79%. This scenario implies that the Kathmandu Valley authority will support the installation of photovoltaic solar panels, the use of electric vehicles and electric cookers, and convert solid waste into energy. However, the EV Scenario (electric vehicles) is the one to be given priority in the implementation for its better performance than the other individual scenarios.

PROCEEDINGS OF HYDRAULIC ENGINEERING, 2007

This paper reports on the evaluation of Simple Urban Energy Balance for Mesoscale Simulation (SUM... more This paper reports on the evaluation of Simple Urban Energy Balance for Mesoscale Simulation (SUMM) to two cities (i.e. Kugahara, Japan; Basel, Switzerland) in winter, spring and summer. This new version of SUMM is incorporated with vegetation scheme to meet the existence of vegetation fraction in real city. SUMM simulated the urban energy balance and radiative temperature (T r) generally well in Kugahara and Basel. However, SUMM slightly underestimated T r in the nighttime and overestimated T r in the daytime in Basel.