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"The spectral intensity of direct and scattered solar radiation is of fundamental importance for various studies in civil engineering, agriculture, solar power generation, and radiation budget estimation. In this paper, we describe a ground-based, wide-spectral-range sensor that can be used for measuring spectral intensities both in the visible and near-infrared spectral regions. The measurements are conducted either with artificial light sources or direct/scattered solar radiation. The measured spectra yields information on the absorption features of atmospheric gases such as nitrogen dioxide (NO2), carbon dioxide (CO2) and water vapor, as well as aerosol optical properties in the atmosphere. Relatively weak absorption of nitrogen dioxide is measured with the technique of differential optical absorption spectroscopy (DOAS), whereas aerosol, carbon dioxide, and water vapor amounts are measured by matching the observed spectra with simulated ones. Both High Resolution Transmission (HITRAN) and Moderate Resolution Atmospheric Transmission (MODTRAN) database/codes are used to derive column amounts of absorbing molecular species and to characterize aerosol optical properties."

"The spectral intensity of direct and scattered solar radiation is of fundamental importance for various studies in civil engineering, agriculture, solar power generation, and radiation budgetestimation. In this paper, we describe a ground-based, wide-spectral-range sensor that can be used for measuring spectral intensities both in the visible and near-infrared spectral regions.The measurements are conducted either with artificial light sources ordirect/scattered solar radiation. The measured spectra yields information on the absorption features of atmosphericgases such as nitrogen dioxide (NO2), carbon dioxide (CO2) and water vapor, as well as aerosol optical properties in the atmosphere. Relatively weak absorption of nitrogen dioxide is measured with the technique of differential optical absorption spectroscopy (DOAS), whereas aerosol, carbon dioxide, and water vapor amounts are measured by matching the observed spectra with simulated ones. Both High Resolution Transmission (HITRAN) and ModerateResolution Atmospheric Transmission (MODTRAN) database/codes are used to derive column amounts of absorbing molecular species and tocharacterize aerosol optical properties. "

"Reflector is used to increase the amount of solar radiation that the solar panels are exposed with, thus increasing the production of electric power. Parameters and I-V characteristic curve of a solar panel is strongly influenced by the amount of solar radiation received by the solar panels. This paper will discuss the effects of flat reflectors on the parameters and I-V characteristic curve of the solar panels. The parameters are solar radiation and temperature at solar panel, maximum power output (PMPP), voltage when PMPP is reached (VMPP), current when PMPP is reached (IMPP), short circuit current (ISC), open circuit voltage (VOC), and Fill Factor (FF). In this study, the types of reflector material are stainless steel mirror and aluminum foil. Reflector is placed beside solar panels. Reflector tilt angle was varied at 30, 45, 60, and 75 degrees. The measurement results show that the greatest increases in solar panel producing electric power are achieved at 75 degrees tilt angle. Aluminum foil reflector and stainless steel mirror can increase power output of solar panels until around 31.5 % and 21.5% respectively. In this tilt angle, for these two types of material reflector, VOC and VMPP tend not to change, ISC, IMPP, solar radiation and temperature on solar panel are increasing, whereas FF is decreasing around 4%. Changes in these parameters refer to the condition without a reflector."

"Pada saat ini solar cell sudah banyak digunakan dalam kehidupan sehari-hari. Solar cell yang terpasang kebanyakan bersifat statis. Hal ini mengakibatkan penyerapan energi matahari oleh solar cell kurang optimal. Agar penyerapan energi matahari oleh solar cell optimal, maka solar cell harus mempunyai system yang selalu mengikuti arah matahari. Skripsi ini membahas tentang solar tracking system yang terdiri dari solar tracker. Solar tracking system yang dibuat merupakan prototype. Solar tracker berfungsi untuk mengoptimalkan penerimaan energi matahari oleh solar cell. Hasil pengujian yang diperoleh yaitu solar tracker yang dibuat belum berfungsi dengan baik karena kesalahan penempatan posisi LDR dan sudut ideal untuk penempatan LDR terhadap garis normal adalah 41.85°. Dari hasil tersebut disarankan bahwa untuk program lebih lanjut penempatan LDR pada sudut 41.85°, dimensi papan solar cell dicari yang ideal dan adanya solar charging."

"ABSTRAKElektrifikasi yang rendah dan terbatasnya penyediaan akses air terkendala untuk didaerah pedalaman atau jauhnya tempat resapan dengan objek tempat yang diairi. Berbagai upaya telah dilakukan untuk menyelesaikan masalah ini, salah satu solusi alternatif yang kami usulkan adalah sistem terintegrasi pompa bertenaga surya dengan konsep DC. Kami menginvestigasi sistem yang optimum dana efisiensi keterkaitan daya pada pompa bertenaga surya sebelum dan sesudah dipasangnya solar panel. Adapun beberapa kriteria yang menjadi perhatian, pada konfigurasi sistem sebelum pemasangan solar panel untuk mengetahui keterkaitan ketinggian atau total head terhadap laju alir dimana ketinggian total lift sebagai variabel bebas (variasi pertambahan setiap 1 meter) dan daya diasumsikan sebagai variabel tetap (suplai daya hanya berasal dari baterai). Dengan skema ini, didapatkan efisiensi dari empat kondisi dimana nilai efisiensinya berturut-turut sebagai berikut 2.73%, 12.21%, 18.44% and 15.34%; Sementara itu, pada konfigurasi sistem sesudah pemasangan solar panel dengan variabel bebasnya adalah daya (4x30 Wp, dan 6x30 Wp) dan variabel tetapnya adalah = 1.33 m, diketahui nilai efisiensi berturut-turut sebagai berikut ; 11.92% and 11.78%.

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ABSTRACTIn a rural area, where electricity supply is limited, water accessibility for the society generally becomes a major concern. Here, we proposed the alternative solution which is an integrated solar-powered water pump system using the DC concept. We investigated the optimum condition and the power conversion before and after the installation of photovoltaic (PV) panels. The correlation between the total water lift and flow rate has been determined as one the parameter designing the PV panel integration by assuming the total water lift as independent variables (H0, H1, H2, and H3 with 1-meter increment) and the electrical power as a dependent variable (the power supply only comes from battery). Using these schemes, we calculated the efficiency of these four different conditions were 2.73%, 12.21%, 18.44%, and 15.34%, respectively. Meanwhile, after PV panel integration in which the total head H1 =1.33 meter as dependent variables and PV modules as independent variables, the efficiency of the submersible Water DC pump powered by a PV module of 4x30 Wp and 6x30 Wp reached 11.92% and 11.78% subsequently."

"ABSTRAKSolar energy is a huge and infinite source of energy so that solar energy can support energy resilience. Parabolic solar cell reflectors use mirrors. The purpose of this research is to determine the thermal collector's power and thermal efficiency on solar stoves. This research methodology is by taking data with time parameters that have been determined according to environmental conditions. The subjects of this study were parabolic solar cookers with a diameter of 84 cm to 500 gram water. The results of the average stove power obtained by 141.71 Watt and the thermal efficiency of the stove by 5.45%. The power of the stove is affected by the difference in temperature of the water after it has been heated by the temperature of the water before it is heated. The greater the temperature of the water after heating it will increase the power of the stove. The greater the overall heat transfer Qm and the smaller the intensity of solar radiation on the reflector using a mirror, the greater the thermal efficiency."

"Berwudu merupakan hal yang sangat penting bagi seorang muslim. Dalam pelaksanaannya, Rasul SAW. menganjurkan untuk senantiasa berhemat air dalam berwudu, baik pada kondisi sumber daya air sedang melimpah maupun tidak. Bahkan, Rasul mencontohkan wudu dengan takaran cukup 1 mud atau sama dengan 675 ml. Indonesia, dengan mayoritas masyarakatnya beragama Islam (87,2% atau lebih dari 207 juta orang), disayangkan masih mubazir dalam menggunakan air untuk berwudu. Beberapa penelitian mengemukakan bahwa rata-rata konsumsi air orang Indonesia dalam sekali wudu mencapai angka sebesar 3-4 liter. Dalam mengatasi kemubaziran penggunaan air wudu di Indonesia, terdapat beberapa peneliti yang telah mengemukakan solusi berbasis teknologi tanpa memerlukan biaya yang besar ataupun harus membongkar instalasi keran yang telah ada. penelitian ini berupaya menyempurnakan alat penghemat air wudu yang telah ada, dengan menggunakan konfigurasi yang menunjukkan hasil terbaik dari penelitian yang sudah ada, serta menggunakan panel surya mini untuk mengetahui apakah dapat digunakan untuk alat penghemat air wudu. Hasil menunjukkan bahwa penggunaan alat ini pada keran air wudu dapat menghemat volume air wudu sebesar 26% hingga 70% dengan rata-rata penghematan sebesar 53%. Perbedaan gerakan tidak memengaruhi responsivitas alat dengan nilai keterlambatan sebesar 0,18 detik. Alat memiliki daya tahan hingga 10.800 kali penggunaan dan berpotensi lebih. Waktu pengisian baterai oleh panel surya mini yang digunakan yaitu 3 minggu untuk kapasitas baterai alat 27,75 Watt dengan jam efektif panel surya selama 4 jam per harinya.

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Ablution is very important for a Muslim. In its implementation, Rasul SAW. teach to always save water in ablution, both in conditions where water resources are abundant or not. In fact, Rasul gave an example of ablution with a measurement of 1 mud or equal to 675 ml. Indonesia, with the majority of the population are Muslim (87.2% or more than 207 million people), unfortunately it is still inefficient in using water for ablution. Some studies show that the average Indonesian water consumption in ablution reaches 3-4 liters. In addressing the inefficient use of ablution water in Indonesia, there are some researchers who have proposed technology-based solutions without the need for large costs or have to dismantle existing tap installations. This research seeks to perfect the ablution water saver that already exists, using configuration that shows the best results from existing research, and using a mini solar panel to find out whether it can be used for a ablution water saving device. The results show that the use of this device in the ablution water tap can save the volume of ablution water by 26% to 70% with an average savings of 53%. The difference in motion does not affect the responsiveness of the device with a delay value of 0.18 seconds. The device has a durability of up to 10,800 times of use and potentially more. The battery charging time by used mini solar panel is 3 weeks for 27.75 Watt battery capacity of the device with an effective solar panel clock for 4 hours a day."

"Instalasi solar panel terapung memberikan dampak berupa terhalangnya cahaya matahari, yang merupakan sumber energi fitoplankton untuk melakukan fotosintesis, masuk ke badan air. Perubahan dalam aktivitas fitoplankton akan memengaruhi produktivitas primer serta konsentrasi sejumlah nutrien yang terlibat. Penelitian ini bertujuan untuk menganalisis pengaruh penutupan permukaan badan air berupa solar panel terapung terhadap perubahan produktivitas primer dan konsentrasi nutrien yaitu nitrat, amonia, dan fosfat perairan, serta hubungan antara produktivitas primer dan konsentrasi tiap nutrien. Penelitian dilakukan dengan objek studi Danau Mahoni UI dengan jumlah pengambilan sampel sebanyak 8 kali dalam kurun waktu delapan minggu. Analisis data dilakukan dengan menggunakan uji parametrik independent t test dan uji korelasi Pearson's. Penutupan permukaan danau oleh solar panel terapung memberi pengaruh yang signifikan secara statistic terhadap penurunan produktivitas primer danau dengan rata-rata penurunan produktivitas primer danau -79,79%, dan pengaruh yang tidak signifikan secara statistik terhadap peningkatan konsentrasi nutrien dengan rata-rata peningkatan konsentrasi nitrat 3,45%, amonia 18,96%, dan fosfat 4,87%. Korelasi produktivitas primer dengan konsentrasi nitrat dan amonia danau lebih kuat pada keadaan tanpa penutupan permukaan danau, sementara korelasi produktivitas primer dengan konsentrasi fosfat danau lebih kuat pada keadaan dengan penutupan permukaan danau.

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Floating solar panel installation has an impact of blocking the sunlight, which serves as the source of energy for phytoplankton photosynthesis, to reach the water bodies. Changes in phytoplankton activities will affect water primary productivity and the concentration of involved nutrients. This study aims to analyze the effect of covering water bodies by floating solar panel on water primary productivity and nutrients (nitrate, ammonia, phosphate) concentration changes, and the relationship between water primary productivity and each nutrient concentration. The study is carried out with Lake Mahoni UI as the study object, with 8 times sampling in the span of eight weeks. Data analysis uses independent t test and Pearson's correlation. The covering of lake by floating solar panel has statistically significant effect on the decrease of lake primary productivity with average decrease of -79,79%, and statistically insignificant effect on the increase of lake nutrient concentration with average increase of 3,45% on nitrate concentration, 18,96% on ammonia concentration, and 4,87% on phosphate concentration. The correlation between lake primary productivity and nitrate and ammonia concentration is stronger without the covering of water bodies, while the correlation between lake primary productivity and phosphate concentration is stronger with the covering of water bodies."

"Energi terbarukan telah menjadi topik penting dalam beberapa tahun terakhir karena meningkatnya kekhawatiran tentang perubahan iklim dan keterbatasan energi fosil. Salah satu sumber energi terbarukan yang menjanjikan adalah energi matahari, yang dapat dimanfaatkan tanpa menghasilkan emisi zat sisa dan tersedia di seluruh tempat. Salah satu aplikasi pemanfaatan energi matahari adalah Solar Thermal Cooling System (STCS), yang menggantikan sistem pendingin konvensional yang menggunakan refrigeran sintetis dan berkontribusi terhadap emisi gas rumah kaca. Evacuated Tube Solar Collector (ETSC) adalah salah satu jenis kolektor surya yang digunakan untuk memanaskan air dan memiliki efisiensi lebih tinggi dibandingkan kolektor surya datar karena menggunakan tabung vakum yang mengurangi kehilangan panas. Pada penelitian ini, performa ETSC diuji dengan menggunakan reflector di bagian bawah tabung yang divariasikan jenisnya, yaitu pelat galvalum dan pelat aluminium, dengan standar ASHRAE 93-2003 sebagai referensi. Pengujian dilakukan pada sudut kolektor surya 15° dengan flowrate sebesar 2,6 LPM. Hasil penelitian menunjukkan bahwa ETSC dengan reflector aluminium memiliki efisiensi rata-rata tertinggi (63%), diikuti oleh ETSC dengan reflector galvalum (55%), dan ETSC tanpa reflector (50%). Penggunaan reflector aluminium meningkatkan efisiensi sebesar 13%, sementara reflector galvalum meningkatkan efisiensi sebesar 5%. Oleh karena itu, penggunaan reflector aluminium lebih efektif dalam meningkatkan efisiensi ETSC dibandingkan dengan reflector galvalum. Hasil penelitian efisiensi ETSC tanpa reflector ini memiliki nilai lebih rendah daripada nilai efisiensi dari standar pengujian perusahaann yang sebesar 75%. Hal ini dapat disebabkan oleh beberapa faktor seperti perbedaan kondisi pengujian, kualitas peralatan, dan desain dan instalasi.

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Renewable energy has become a significant topic in recent years due to growing concerns about climate change and the limitations of fossil energy. One promising source of renewable energy is solar energy, which can be harnessed without producing emissions and is available everywhere. One application of solar energy utilization is the Solar Thermal Cooling System (STCS), which replaces conventional cooling systems that use synthetic refrigerants and contribute to greenhouse gas emissions. The Evacuated Tube Solar Collector (ETSC) is a type of solar collector used to heat water and has higher efficiency compared to flat plate solar collectors because it uses vacuum tubes that reduce heat loss. In this study, the performance of ETSC was tested using reflectors at the bottom of the tubes with different types, namely galvalume plates and aluminum plates, with ASHRAE 93-2003 standards as a reference. The tests were conducted at a solar collector angle of 15° with a flow rate of 2,6 LPM. The results showed that ETSC with an aluminum reflector had the highest average efficiency (63%), followed by ETSC with a galvalume reflector (55%), and ETSC without a reflector (50%). The use of an aluminum reflector increased efficiency by 13%, while the galvalume reflector increased efficiency by 5%. Therefore, the use of an aluminum reflector is more effective in improving ETSC efficiency compared to the galvalume reflector. The efficiency results of ETSC without a reflector are lower than the company's standard test efficiency value of 75%. This can be caused by several factors such as differences in test conditions, equipment quality, and design and installation."