Extremely inflated wattage claims

[Hdonly]

I have been searching for flexible solar panels for a small electric boat project I would like to build. It appears most of the flexible panel sellers out and out lie about the panels output. They claim 100 watts-200 watts for panels about 26" x 44". To me those ratings are totally impossible under any conditions except maybe on the planet Mercury. Do any companies actually make flex panels that that don't inflate their numbers so much?
Woops. The W x L I meant to quote that I found rated at 100 watts is 13" x 26" found on ebay @ $115 for two, sold as a 200 watt package.

 

[Solarcabin Channel]

Renogy 100 watt flexible are 47.9 x 21. So yeah, you can get 100 watts out of a panel that size.

However, flexible have lower efficiency and generally don't last as long. Good for applications where portability, flexibility and weight are a consideration.

Panels are generally rated at 75 degrees and in cooler temps in direct sunlight you can get even more than the rated output.

I use one on my Ebke solar trailer because of the weight factor but for a permanent install I would use framed panels.

 

[SeaGal]

Panels usually come with 2 pre-defined wattage measurements.

a) the STC. This is Standard Test Conditions and is a simulation of peak wattage possible in perfect ideal conditions. Specifically a Cell temperature of 25°C and receiving an irradiance of 1000 W/m².

b) the NOCT. This is the Nominal Operating Cell Temperature measurement and is designed to better reflect real-life situations. Specifially with ambient temperature of 20°C and receiving an irradiance of 800 W/m².

The key differences being the amount of light and the temperature being the actual air temp, rather than the cell temp. The STC is somewhat optimistic as cells heat up with sunlight on them and current flowing through them, so difficult to keep a cell at 25°C when receiving an irradiance of 1000 W/m².

Best IMHO to look at both NOCT and panel efficiency % values to compare different panels' performance.

 

[chrisski]

I use 180 watts per meter square of surface are. + or - 10% does not worry me.

This is to ensure vendors don’t inflate numbers. There’s been vendors that “accidentally” listed an30 watt panel as 300 by “mistakenly” adding a 0.

I use Renogy and find their panels as advertised. I took the size of the panel and divided by watts to get that number.

 

[Hdonly]

I edited my first post. See above.