Energy and Exergy Performance Calculation of Solar Photovoltaic/ Thermal Hybrid System under the Baghdad Environment

Abstract

A combined system with photovoltaic panel modules, which extracts heat from water or air and produces thermal and electrical energy which is called a solar photovoltaic or solar thermal photovoltaic thermal (PV/T) system. A way to enhance the electrical efficiency of the PV module is by diminishing the temperature at which the module is working, i.e. by extracting thermal energy. The design of the solar Photovoltaic/Thermal provides certain advantages. When the temperature is increased 1°C, the photoelectric efficiency decrease by 0.5%. This work is principally aimed to clarify the effectiveness by means of the exergy generated in a PV/T hybrid water module, a photovoltaic thermal module, generating thermal and electrical energy. Were determined the energy, exergy and the efficiency of the power conversion for a certain amount of days in function of the solar intensity, the temperature of the module and environmental temperature. During the hours 9:00 am to 3:00 pm, the efficiencies of exergy and power conversion varies according to the following values, between 2.16 - 12.27% for the exergy efficiency and between 5.2 - 11.2% for the power conversion efficiency as well as, the energy efficiency varies between 6.89 – 14.9%. The temperature of the photovoltaic module has a great impact on the electrical, thermal and exergy efficiencies. Moreover, these efficiencies can be enhanced by removing energy in form of heat from the surface of the photovoltaic module.

Three‐dimensional computational comparison of mini‐pinned heat sinks using different nanofluids: Part two—energy and exergy characteristics

“…The first law of thermodynamics is applied to find the thermal energy efficiency ( η EX ), which points out the quantity of energy. However, the second law of thermodynamics is used to determine the exergy loss (Ex) and exergy efficiency ( η EX ), which refer to energy quality . Thus, in the present evaluation, the energy dissipation could be represented by three main products such as pressure drop, exergy loss (Ex), exergy efficiency ( η EX ), and energy efficiency ( η EX ) as well as pressure drop is considered.…”

“…The exergy denotes the amount of the most significant work, which mean the heat sinks system could be eliminated as the system submits to a reversible process from the original to the final state. Thus, the design and assessment of energy devices could be investigated by exergy performance, which is the quality of variation in the energy of the devices until they achieve an equilibrium state with the surroundings …”