[groar]

Originally Posted by groar

Oops, Wc may be the French term ("Watt Crête"), which can be translated by "Peak Watt" but I don't know if this is the English term. This is the output of the panel at normalized conditions: iirc 20°C and 1000W/m², imho the alignment is certainly normalized too but I can't remember about this detail.

Denis.

From Watt-peak - Wikipedia, the free encyclopedia :

Watt-peak (Wp) is the DC power output in watts of a solar module as measured under an industry standardized light test before the solar module leaves the manufacturer's facility. The light test tests the output power when illuminated under standard conditions of 1000 watts of light intensity per square meter, 25 °C ambient temperature and a spectrum similar to sunlight that has passed through the atmosphere (air mass 1.5).

But other parameters are also important :

It can happen that a panel from brand A and a panel of brand B give exactly the same watt-peak in a laboratory test; but in a real installation the power output can be different. This difference can be caused by the fact that in real conditions the temperatures are different and the photovoltaic cell temperature will go up. Photovoltaic cells have a different characteristic at different temperatures; a low efficiency cell will become hot and with higher temperature the efficiency will go down and produce less power.

Denis.