Image: O’Connor College of Law/Flickr
Developed by researchers in Saudi Arabia, the novel approach considers both the temperature-dependent power yield and the solar module time to failure (TTF), among other factors. According to its creators, the model can be applied to all kinds of module and cell technologies.
From pv magazine
Researchers from Saudi Arabia’s King Abdullah University of Science and Technology (KAUST) have developed a temperature-dependent levelized cost of energy (LCOE) model for PV technologies that is claimed to be able to quantitatively translate the LCOE gain obtained by reducing solar module temperature. “Our model can be applied to all kinds of module and cell technologies,” the research’s corresponding author, Lujia Xu, told pv magazine. “It was validated through a series of tests conducted at an outdoor testing field located in Singapore.”
The model considers both the temperature-dependent power yield and the solar module time to failure (TTF), which calculates the time from when the panel is put into service until it fails. These two values were then unified in an equivalent ratio, designated with the Greek letter γ, which evaluates the influence of temperature on the performance of a PV system.
“This ratio expresses which absolute percentage in power conversion efficiency increase would be needed for achieving the same reduction in LCOE,” the scientists explained, noting that the model allows the prediction of a module’s temperature from the basic solar cell and module materials and device architecture properties. ” Whereas the temperature-dependent LCOE speaks to those working at system level, γ provides technologists working at the module and cell level with a more tangible metric.”
The model is said to enable the calculation of the total cell heating power by either adding the components contributing to the cell heating or by subtracting the electrical power output of the cell/module and the reflected/escaped power from the incident power. “We find that more than 60% of the incident solar power leads to cell heating,” the Saudi Group stated. “In addition, the encapsulation of the cells into modules further increases the heating power to over 65% of the incident power.”
In order to create a quantitative link between the module heating-power density and the module temperature, the scientists also developed an opto-electronically coupled thermal model to compare the thermal behavior of different cell technologies and investigate possible strategies for mitigating potential heating issues. “We found that the most effective and simple way to reduce the module temperature is to place the module in a windy environment with a proper mounting arrangement to enable effective heat transfer via convection,” the researchers concluded.
The proposed model was described in the paper Heat generation and mitigation in silicon solar cells and modules, which was recently published in Joule.
Author: Emiliano Bellini