An enhancement in electrical efficiency of photovoltaic module

摘要

Energy is considered as a prime agent in the generation of wealth and a significant factor in the economic development. The development scale of any country is measured by few parameters among which per capita energy consumption holds the most significant. With the depletion of nonrenewable energy resources and growing environmental concerns, it is expected that solar energy i.e. a renewable energy source is going to play a very significant role in the future. Over the last three decades, a significant research on photovoltaic (PV) solar cells and modules has been carried out. Today, the electricity conversion efficiency of a silicon solar module available under standard test condition (I(t)=1000 W/m² & T_a = 25°C) for commercial application is about 12 %. More than 75% of the incoming solar energy is either reflected or converted into heat energy. The abundant solar energy obtained from solar radiation can be utilized in the form of either thermal energy or electrical energy (DC) using photovoltaic (PV) modules. The efficiency of the PV system is more sensitive to the operating temperature. The higher the operating temperature, lower is the electrical efficiency and vice-versa. The operating temperature of PV systems can be lowered by withdrawing/utilizing the thermal energy associated with it. The thermal energy associated with the PV module can be carried away by flowing air below it. This type of system is known as hybrid photovoltaic thermal (PVT) system. The hybrid PVT system allows the enhancement of the electrical performance of PV by removing thermal energy and subsequently decreasing the operating temperature. Standalone Photo voltaic (SPV) systems has less electrical efficiency hence long payback period is observed. The parameter performance ratio is usually employed for performance of SPV systems. This paper illustrates that both types of energy are generated and by utilizing both types of energy, payback period can be reduced hence performance is improved. SPV system is mounted on roof of administrative building of University. It has been observed improvement in average electrical efficiency is 7.02%.