Solar panel can act as a medium for transforming sunlight into electrical energy. Nevertheless, not all of the sunlight received on this device can be converted into electrical energy and the remainder will be dissipated into thermal energy. If a solar panel is continuously exposed to the sun, so its temperature will increase and thereby reduce its electrical efficiency. To deal with the issue, it may combine a PV panel with a thermal collector which is called a hybrid PV/T collector. Furthermore, in the present study the effects of fluid flow direction and mass flow rate on the thermal and electrical efficiency of the PV/T collectors are extensively analyzed. Single and double pass collectors with rectangular plate fin absorber were attached to backside of the PV panel. They were tested using a solar simulator with different flow rate ranging between 0.01 and 0.05 kg/s of the working fluid. The results show that the use of double pass PV/T air collector increase its performance compared with the single pass one. The highest values obtained from this type collector are found to be 73.23% in the thermal efficiency and 10.16% in the electrical efficiency with the working fluid mass flow rate of 0.048 kg/s.

The night air temperature which is below or equal to the temperature of human thermal comfort is very potential to be used to help reduce the thermal load of the room. This utilization can help minimize the electrical energy consumption of air conditioning systems. Phase change material (PCM) can be used to utilize the potential of cold air at night as latent heat thermal energy storage (LHTES). One model of the application of PCM is the heat exchanger. PCM fills one part of the heat exchanger. The characteristics of heat transfer need to be known so that it can know the cooling rate and the time required in the process. The variable used in this study is the inlet air velocity. In this research, a staggered fins-type heat exchanger which contains PCM with paraffin material is used in the cooling process. The results showed that an increase in speed would accelerate the cooling rate. At a velocity of 3 m.s−1, the average cooling rate of the PCM mass unity was 6.4 °C.hr’.kg−1. With this rate of cooling, the potential for cold night air for about two to three hours can be utilized for the PCM freezing process.

Kolektor surya pelat datar sering digunakan dalam memanfaatkan energi surya. Kolektor ini memiliki keuntungan yaitu dapat menyerap dengan baik radiasi matahari. Untuk mengkarakteristik unjuk kerja kolektor surya dapat digunakan metode Computational Fluid Dynamic (CFD). CFD memberikan kemudahan untuk menganalisis karakterisrik aliran fluida. Tujuan dari penelitian ini adalah melihat karakteristik unjuk kerja termal dan pressure drop kolektor surya pelat datar aliran spiral dan serpentine menggunakan CFD. Langkah-langkah yang dibutuhkan dalam proses simulasi CFD meliputi: desain dan name selection geometri. meshing. pemilihan metode radiasi. pemilihan jenis material dan input kondisi batas. Kemudian proses validitas dilakukan terhadap hasil simulasi dengan cara membandingkan dengan data eksperimen aliran serpentine. Langkah selanjutnya mensimulasikan kolektor surya pelat datar aliran spiral dengan metode CFD kemudian hasilnya dibandingkan dengan hasil data simulasi aliran serpentine. Hasil penelitian ini menunjukan bahwa untuk jenis aliran spiral setiap kenaikan laju aliran massa sebesar 0.005 kg/s maka temperatur maksimal fluida kerja akan mengalami penurunan sebesar 2°C. Kemudian pada laju aliran massa terbesar yaitu 0.02 kg/s. pressure drop maksimal fluida kerja (air) ialah 1339 Pa. Penggunaan jenis aliran spiral pada kolektor surya pelat datar akan meningkatkan nilai temperatur keluar fluida kerja (Tout) sebesar 3.14 % dan menurunkan temperatur permukaan kolektor sebesar 6.4 %   serta   pressure drop fluida sebesar 15.08 %. Flat plate solar collectors are often used in harnessing solar energy. This collector has the advantage of being able to absorb solar radiation well. To characterize the performance of the solar collector. the Computational Fluid Dynamic (CFD) method can be used in the present study. CFD provides benefits for analyzing fluid flow characteristics. The purpose of this research is to characterize the thermal performance and pressure drop of spiral and serpentine tube solar collectors using the CFD method. The steps required in the CFD simulation process include the design and selection of geometry names. meshing. radiation planning. selection of material types and input conditions of boundary conditions. Then the validity process is carried out and compared to those obtained from experimental data. The next step is to simulate for both the thermal performance and pressure drop of spiral and serpentine flow solar collectors flat using the CFD method. In comparison with the serpentine flow type. the use of the spiral flow type on the flat plate solar collector will increase the value of the outlet working fluid temperature (Tout) by 3.14%. Otherwise. the use of the spiral flow type will reduce collector surface temperature by about 6.4 % respectively and the pressure drop of working fluid by about 15.08%.