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"Penggunaan energi alternatif sebagai catu daya Base Transceiver Station (BTS) 3G dapat mengatasi permasalahan pasokan listrik PLN yang belum mencapai seluruh wilayah Indonesia. Penggunaan modul sel surya menjadi salah satu solusi yang dapat dipertimbangkan sebagai catu daya BTS, sedangkan energi angin dapat digunakan ketika irradiansi matahari tidak dapat memenuhi kebutuhan beban. Nilai tegangan keluaran sel surya dan turbin angin yang tergantung keadaan lingkungan di sekitar pembangkit menyebabkan perlunya rangkaian untuk menjaga agar nilai masukan ke beban selalu konstan. Skripsi ini menggunakan rangkaian switching regulator dengan IC L4970 yang mempunyai nilai tegangan keluaran 15 volt. Pemilihan antara kedua energi alternatif ini menggunakan mikrokontroller ATMEGA16 dan dua buah relai. Simulasi sistem hybrid catu daya ini dapat menjamin suplai catu daya BTS selalu tersedia dengan nilai tegangan masukan yang konstan dengan lama waktu switching 2 ms.

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Using of alternative energy source such as solar cell and wind power could over come problem about power supply from PLN for Base Tranceiver Station (BTS). Solar energy can be extracted from solar cell power generator for one of main alternative source in BTS. When the power of sunlight is not adequate to be converted into solar cell power, the wind power generator could become a secondary alternative source. The output of solar cell and wind turbine depend greatly on surrounding environment. This condition requires a certain circuits on the power generator to maintain a constant number on the load input.

The circuits used in this project are switching regulator with IC L4970 with an output of 15 volt. The decision of choosing between two alternative energies are excecuted by ATMEGA16 microcontroller with two relays. This hybrid power system guarantees suplai catu daya is available with constant input number."

"Platinum is the most effective counter electrode for use in dye-sensitized solar cells (DSSC). However, as platinum is very expensive, its price impedes its broad use as a DSSC counter electrode. As an alternative, carbon has been used for this purpose. In this study, carbon has been successfully pyrolyzed from the precursors of table sugar and sucrose through a chemical process, i.e. the dehydration of the precursors with sulfate acid followed by a pyrolysis process, and used as Pt-less counter electrode in a DSSC device. The as-synthesized carbon was characterized using X-ray diffraction (XRD) to obtain crystal structure information and a scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) was employed to carry out morphological and compositional examination. The material activity and performance of the counter electrode in the DSSC device were analyzed using a semiconductor parameter analyzer through current–voltage characteristic curves (I-V). The results show that the precursors of table sugar without the addition of a metal catalyst and with initial heat treatment at 300°C for 1 hour, and of sucrose with a catalyst could produce carbon with a particle size of around 600–900 nm. The I-V curve characteristic of the DSSC device assembled using carbon produced from sucrose as a counter electrode resulted in a power conversion efficiency (PCE) of only 0.041%, whereas the DSSC device assembled using carbon produced from table sugar as a counter electrode exhibited a good performance with a PCE of 3.239%, almost equivalent to that of platinum paste with a PCE of 4.024%. This result is promising in terms of using a cheap source of carbon for the Pt-less counter electrode."