Volume 31: Clean Energy Technologies towards Carbon Neutrality

An efficient hybrid system integrated concentrated parabolic trough solar collector with solar photovoltaics Qiliang Wang*, Hongxing Yang*

Abstract

The concentrated parabolic trough solar power is regarded as a promising renewable alternative expected to exert a vital role in supplying green and sustainable electricity and thermal energy for the human race in the future. However, the parabolic trough collector (PTC) system still encounters a knotty problem of considerable radiation heat loss caused by its high operating temperature (generally above 400 °C), which significantly degrades the thermal performance of the PTC system and thus power generation performance of the PTC power plant. In this work, a novel PTC system integrated with solar photovoltaics (PTC-PV) is proposed. The PV panels have a narrow width which is the same as the diameter of the parabolic trough receiver (PTR), and are placed above the PTRs at a certain distance. In addition, the rear surfaces of the PV panels are covered with a high-reflective coating used to block the radiation heat loss from the PTR. The unique configuration of PV panels in the PTC-PV system is expected to reduce the radiation heat loss of PTRs and simultaneously generate electricity in an efficient manner due to the sun tracking mechanism of the PTC system. In this research, a test rig of the proposed PTC-PV system was established in the Hong Kong Polytechnic University. The comprehensive experiments were carried out. In the experiments, PV efficiency under different PTR’s operating temperatures and solar irradiances were explored. Moreover, the overall performance of the PTC-PV system was also evaluated and compared with the traditional PTC system. The experimental results showed that the PV panels in the PTC-PV system maintained superior photoelectric efficiency compared to the traditional PV system without sun tracking. The high-reflective coating covered on the rear surface of the PV panel can effectively reduce the PV temperature when the temperature of the glass tube in the PTR is above 75 °C. And the electricity capacity of the PTC-PV based concentrated solar power plant is effectively improved by 1.1 % compared to the traditional PTC based concentrated solar power plant.

Keywords Solar Energy, Concentrated Parabolic Trough Collector, Photovoltaic, Solar Power, Integrated system