Objective: To improve the reutilisation of heat lost due to convection from the cell to ambient air. For this purpose, initially parameter like efficiency of cell with tin oxide coating and fill factor of cell with tin oxide coating for various cross sections are envisaged.In the later stages the heat lost due to convection in predicted from the transient analysis on single cell considering it as a flat plate collector.
Methods/Statistical analysis: Experiments are conducted to apply a thin film-coating layer of tin oxide on solar cells (silicon wafers) by a thermal vapour process under high vacuum, followed by annealing with an objective of reducing the reflection.Theoretical analysis is carried out on single solar cell and on an array of cells (solar collector) to assess quantitatively the convection heat loss rate to the ambient air during the process of heat absorption by the cells.
Findings: The tests conducted with the nano-coated solar cells showed that the cell efficiency has increased from 24% without coating to 31% with an optimum coating 400 nm thicknesses has been found. The results of the theoretical analysis conducted on a single cell reveal a 2% saving in the heat loss from the cell with nano-coating compared to that without coating. As the coating thickness is increased from zero to 600nm the heat loss due to convection decreased monotonically from 461.4 to 452 W/m2.
Application/Improvements:These thin films can be used in various applications like gas sensors, solar cell and sensors.