Comparing TSM with standard PV
A traditional pv solar system (with the majority of energy being generated outside the time of maximum demand)...
Is comprised of a series or string of PV cells which form a solar panel which is traditionally glass covered, with a glass composite backing material that creates an encapsulated 'hothouse' effect. Standard PV specifications are obtained under the standard test conditions (stc's): 1000 w/m2 solar irradiance, 1.5 air mass and cell temperature of 25ºc.
If the ambient atmospheric temperature is 25ºc, then the panel temperature will be approximately 60ºc as a result of the PV cells being heated to 35ºc above the ambient temperature. This increase in cell temperature is due to the " hothouse” effect and has a detrimental effect on the energy output performance of the cell which in turn, impacts on the performance of the traditional PV solar system.
For every 1ºc increase in the temperature of a PV cell, there is up to a 0.6% decrease in the efficiency of that cell. Accordingly, if the ambient temperature is 25ºc, the traditional solar panel will reach a temperature of 60ºc (25ºc + 35ºc) which means that the traditional PV system will lose efficiency output of up to 21% of its stated efficiency. This means that if a PV cell is rated under standard test conditions at achieving an efficiency of 15%, then on a 25% c day, the cell's efficiency is reduced to 11.85%.
If there is not direct solar radiation on the cell due to dirt build-up, bird droppings or shading from trees or buildings, then the entire solar panel may be rendered totally inefficient. The affected area only needs to be the size of a 50 cent coin and therefore the risk of a reduction in the system efficiency is high.