SOLAR PANEL QUALITY
IS SO EAZY TO CALCULATE
“THERE IS NOWHERE TO HIDE”
This article is designed to give assurance to the reader that the Safiery Triple Insulated Solar Panels are constructed from Sunpower Maxeon Level 3 Solar wafers. It also explains how to calculate the quality of any solar panel in the market.
These are the two tables showing the solar panel performance of Sunpower cells as published by Sunpower.
NO WHERE TO HIDE: CALCULATING TRUE SOLAR PERFORMANCE
We have read many websites advertising caravan and 4WD solar panels at lower prices. They nearly always brag about having the “high or even highest efficiency solar panels in the market”.
We simply do the maths to find out the “pork pies” and its “porkies” on nearly every occassion.
How is this done?
It’s very easy you see. Sunpower publish the Voc of their solar wafers. Simply take the number of wafers on the panel and then divide the panel Voc by this number to get the Voc per wafer. Then look up the tables above to determine the quality.
There is a slight complication: If the panel has bypass diodes then the forward voltage loss has to be taken off (one reason whigh high voltage panels have an advantage as the loss is a much smaller pecentage). There will also be a very small voltage loss on the junctions themselves of say 0.1V. We use a 0.8V Diode loss.
Lets look at an example.
Safiery’s highest grade panels are 190W. They have a Voc of 38V. There are 54 wafers in a panel. The Calculation is:
Voltage of Wafers before Diode: 38V + 0.8V +0.1V = 38.9V.
38.9V/54 Wafers = 0.7203V/Wafer
Looking up Chart above these wafers are Maxeon III Bin Le1 which is 0.721 per wafer. This shows the diode and junction drop to be a little more than 0.9V.
Checking the power against the same chart:
54 Wafers x 3.62 Wp per wafer = 195.48 Watts
Loss of 0.9V x 6.15Isc Loss on Diode/Junction = 5.535 W
195.48 – 5.535 = 190.013Wats
The Maths Check out. No Porky Pies here!
To check out your own panels follow this proceedure. If the wafers are not Sunpower, use the above as a guide. Here is the Summary of Sunpower Wafers/Cells.
of Loss per Degree C
> 25Deg C