Calculate Panel Capacity from Dimmensions?

[swvic_matt]

Hello,
Is it possible to determine what capacity panel I can get, for given dimensions?

I have a space on my RV of 1200mm x 650mm where I can mount a panel. Can I use those sizes to determine what capacity panel I can get?

Currently I'm just Googling 200W panels and looking at their dimensions, but this is becoming tiresome.

Thanks for any help.

 

[snoobler]

How to not get completely scammed when purchasing solar panels.

Too many times folks purchase panels from something like Wish or from anonymous on eBay, and they later realize they were sold LIES. Sanity check your purchase in the following two ways: Panel Length, L, in meters Panel Width, W, in meters. 1000W/m^2 * L * W * 0.2 = absolute maximum possible...

diysolarforum.com

1.2*.65 = .78m^2

1000W/m^2 * .78m^2 * 20% = 156W

 

[fratermus]

Is it possible to determine what capacity panel I can get, for given dimensions?

Yes, but you'll still have to check listing dimensions anyhow to find something that actually fits the space. The L/W dimensions will give you the area in square meters. The area times X the efficiency (.20 or 20% in snoobler's example above) X 1000w will give you rated power (not what you will actually harvest).

Normal consumer panels will be something like 15% efficiency (150w/square meter). High-efficiency (and higher cost) panels may be >= 20% efficiency (200w/square meter. The ubiquitous Renogy 100w mono panel is 15.47% efficient, which would be 121w-rated panel if it were that size.

Given the limited space (and the amount of shadow typically thrown by accessories on RV roofs) instead of trying to mount in a suboptimal space you might consider leaning a couple 100w panels against the south side the RV when encamped.

 

[swvic_matt]

Thank you both for your help.
I was thinking of mounting something on the roof so I can use solar while driving as sometimes we can be on the road for 10 hours.

I'll work out what capacity panel I can use for the area I have, maybe it won't be worth putting a panel on the roof at all???

Thanks for the help and suggestions.

 

[snoobler]

The method I listed is a good starting point for investigating which rating to pursue. Given the computation, 180 or 200W panels are unlikely to fit where 160W and smaller might.

Finding panels based on a physical dimension is tedious.

 

[Ampster]

1000W/m^2 * .78m^2 * 20% = 156W

I have been using a factor of 15 Watts per sq ft, and if we assume a sguare meter is roughly ten sq. ft. we are pretty close. As every one else has stated, finding panel sizes to fit in small spaces is tedious and can be expensive.

 

[swvic_matt]

Yep it sure does take some time.

Thanks for the help, I really appreciate it.

 

[swvic_matt]

I'm looking at a panel that I could make fit in the space. It's listed as 220W.

Size in 930mm x 710mm = 0.66sqM.

So therefore 1000W/sqM x .66 x 20% = 213.85W

But the Voc = 22.5 and Isc = 13.5 which = 303.75W

And the Vmp = 17.5 and Imp = 12.22 which = 213.85W

So it could be a legitimate panel????

 

[Ampster]

But the Voc = 22.5 and Isc = 13.5 which = 303.75W

A panel is not likely to see maximum current and maximum voltage at the same time. The best measure of a panel output is STC Wattage (Standard Test Conditions)