Computational study on water based hybrid photovoltaic systems with different absorber configurations

Area of Science:

• Renewable Energy Systems
• Thermal Engineering
• Photovoltaics

Background:

• Photovoltaic-thermal (PVT) systems integrate solar photovoltaics (PV) with solar thermal collectors to simultaneously generate electricity and heat.
• The thermal absorber is crucial for PVT efficiency, as it mitigates PV temperature rise and captures thermal energy.
• Advanced thermal absorber designs are needed to optimize PVT system performance.

Purpose of the Study:

• To assess and compare different water-based PVT system thermal absorber configurations.
• To analyze the performance of proposed semi-circular thermal absorbers against conventional spiral absorbers.
• To investigate the impact of varying flow configurations on thermal and electrical efficiency.

Main Methods:

• Simulated PVT systems with constant water flow rate and solar radiation were employed.
• Computational Fluid Dynamics (CFD) using FLUENT software was utilized for steady-state analysis.
• Key parameters measured included PV surface temperature, water discharge temperature, and pressure drop at constant ambient and inlet water temperatures (299 K).

Main Results:

• The zigzag thermal absorber demonstrated superior performance, achieving the highest water outlet temperature and lowest PV surface temperature.
• Compared to a non-cooled PV system, the zigzag absorber PVT system yielded an 11.97% increase in electrical efficiency and 76.75% in thermal efficiency.
• The zigzag absorber PVT system achieved 13.61% electrical efficiency and 76.75% thermal efficiency, outperforming the conventional spiral absorber PVT system (13.5% electrical, 54.8% thermal).

Conclusions:

• Thermal absorbers effectively reduce PV surface temperature through cooling, enhancing overall system efficiency.
• The zigzag semi-circular thermal absorber is the most efficient configuration identified in this study.
• The zigzag thermal absorber PVT system presents a viable economic case with a simple payback of 4.63 years and a 28% ROI, making it recommendable for future PVT system improvements.