Chinese solar researchers increase efficiency of solar cells

Chinese scientists have developed a hybrid cooling technique to reduce photovoltaic (PV) module temperatures by up to 12.86 C and increase power yields by 7.25%.

“Researchers from Zhejiang University and Shanghai Jiao Tong University in China have developed a hybrid solar module cooling technique based on radiative cooling (RC) and the use of heat pipes to transfer heat”, PV Magazine reports.

The scientists discussed their findings in “Enhanced radiative cooling of solar cells by integration with heat pipe,” which was recently published in the scientific journal Applied Energy.

The article points out that “thermal management of solar cells is of vital importance to maintain adequate electrical efficiency.”

Lately, radiative cooling (RC) of solar cells has been researched extensively because of its passive nature and structural simplicity. However, commercial solar cells are usually encapsulated with highly emissive glass covers, and therefore the additional potential to reduce the cell temperature through RC is not significant.”

The Chinese study proposes a new system configuration to maximize the radiative cooling potential.

Image: Longi Solar

It consists of a photovoltaic module for electricity generation, an RC module for heat removal to the sky, and a heat pipe for quick and efficient heat transfer between the two modules.

A comparative analysis of temperature reduction and efficiency improvement between the proposed and previously studied systems was conducted. The influence of input parameters (i.e., solar radiation, ambient temperature, wind speed, atmospheric emissivity, radiator length, and heat pipe resistance) on the system performance was also studied.

The results showed that in contrast to the conventional glass-coated module, the proposed system gives a maximum cell temperature reduction of 12.86 °C, which corresponds to a 7.25% relative rise in electrical efficiency. This is significant reduction in solar cell operating temperature and a rise in electrical efficiency is obtained.

The paper said that the “new configuration’s enhanced thermal performance supports it as an alternative to the glass-coated or ideally emissive photovoltaic modules. By addressing the challenge of limited radiative sky cooling, researchers can eventually move a step ahead and use this study for the thermal management of other devices and not just solar photovoltaics.”

Applied Energy, Vol 308, 15 February 2022.!

PV Magazine, 6 January 2022.