The best photovoltaic solar panels
Thought I would share some information on what are rated as the best/most efficient panels available. Sanyo HIT Power N Series. The cells are hybrids of monocrystalline silicone, surrounded by ultr...
Forum Discussion
Salvo wrote:
Virtually all solar panels specify either voltage or power temperature coefficient (or both). If you can't show me a panel with -1.1%/C then that claim is pure nonsense.
I can't believe you're that gullible. Some critical thinking is in order.
Sal
The 1.1%/C was not intended to represent any panel PTC or voltage.
How many degrees of temperature increase over 25C-77F would it take to reduce PTC to 1.1 %?
Contrary to popular belief, the efficiency of a solar cell decreases with increasing temperature. The reason for this is that a higher temperature increases the conductivity of the semiconductor. This balances out the charge within the material, reducing the magnitude of the electric field at the junction.
This in turn inhibits charge seperation, lowering the voltage across the cell.
The listed power of a cell/module is the power measured under ideal labritory conditions at a temperature of 25C (77F).
On a hot summer day it would not be unusual to reach a temperature of 70C (158F).
The rule of thumb is that the efficiency of a cell decreases 0.5% for every 1 degree C (1.8 degrees F) above 25C (77F). This means the efficiency of a cell could easily drop by 25%.
