China
Africa
Explore chapters and articles related to this topic
Improved High-Efficiency Conventional Solar Photovoltaic System: A Novel Approach
Published in Hee-Je Kim, Solar Power and Energy Storage Systems, 2019
The performance of PV modules is generally specified under standard test conditions (STC); however, the performance of the modules under real field conditions differs from the expectations derived from the results under STC due to a variety of continuously changing conditions. Therefore, it is important to monitor the behavior of PV modules under real field conditions with temperatures higher than the ambient temperature defined at STC (25°C). An increase in temperature of the PV module causes the bandgap of the intrinsic semiconductor to shrink, and as a result the open circuit voltage (Voc) decreases. At the same time, a lower bandgap allows more incident energy to be absorbed because a larger percentage of incident light has sufficient energy to raise charge carriers from the valence band to the conduction band; a larger photocurrent results. As the temperature is raised, however, the internal resistance of the material increases and the electrical conductivity decreases. The increase in current for a given temperature rise is proportionally lower than the decrease in voltage. Hence, the efficiency of the cell is reduced. Cooling systems are required to reduce the temperature and increase the efficiency of an SPV module. On the basis of a literature survey and previous work, the following four cooling techniques were compared in an effort to achieve the most effective cooling system for an SPV system.33
Current, voltage and resistance
Published in Mike Tooley, Lloyd Dingle, Engineering Science, 2020
Because of the losses associated with it, internal resistance is important in many electrical applications. We showed how this resistance has an effect on the output produced by a source of e.m.f. This is an important topic that we shall return to later when we investigate the maximum power transfer theorem.
Data-driven state of health monitoring for maritime battery systems – a case study on sensor data from ships in operation
Published in Ships and Offshore Structures, 2023
Qin Liang, Erik Vanem, Yongjian Xue, Øystein Alnes, Heke Zhang, James Lam, Katrine Bruvik
Health monitoring (also known as condition monitoring) for maritime battery systems includes the monitoring of operation, safety, and performance. It can be implemented through onboard monitoring with the battery management system (BMS), using different models and algorithms on data to estimate, or through specific controlled test scenarios. Batteries will lose capacity and experience an increase in internal resistance over time, both by calendar time and by charge/discharge cycles. For ships that rely on onboard battery system for energy, it is important to ensure that the capacity of the battery system is always sufficient for the safe operation of the ship. Therefore, accurate assessment and verification of the capacity and performance of offshore battery systems are critical for the safe and sustainable operation of battery powered ships.
Performance of Paracoccus homiensis DRR-3 in microbial fuel cell with membranes
Published in International Journal of Ambient Energy, 2018
Deepika Jothinathan, Richard Thilagaraj Wilson
Internal resistance (Rin) can be measured by the polarisation slope method, power density method and electrochemical impedance spectroscopy (EIS) method using the Nyquist plot (Manohar et al. 2008a). In earlier studies, methods used to calculate Rin were based on Ohm's law where the ohmic resistance was determined (Rinaldi et al. 2008). EIS is a well-known method that measures the impedance of the fuel cell at different frequencies. EIS has been used in electrochemical research areas such as corrosion (Huet 1998; Kelly et al. 2002) and fuel cells (Wagner et al. 1998). The use of EIS in this technology is to analyse the various processes such as charge transfer resistance, ohmic resistance, polarisation resistance and capacitance (He, Wagner, and Minteer 2006).