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.