UKH

Will a solar panel work when inside an Ortlieb map case?

Can you sunbathe inside a greenhouse?

Plants can photosynthesise inside a greenhouse, greenhouses wouldn't exist otherwise.

In reply to gravy:

Are you sure? His map will block the sunlight.

In reply to gravy:

Way more than 10%. But the real question to the OP is why? Most outdoor orientated panels are water resistant, and you're hardly going to be using a solar panel in the pissing rain...

Ease of use, ortlieb handlebar bags have a transparent map case on top of the bag, for maps obviously, but also handy for phone and prob small solar charger. Just shove it in and zip up the opening and the charger will sit securely on top of the bag.

Yes, but he wants to use his panel inside the case not grow tomatoes in it

Silicon PV operates across an illumination wavelength range of about 300 nm to 1100 nm. The transmission of clear polymers is variable depending on the precise material. From the following: https://www.gsoptics.com/transmission-curves/ things look pretty flat across that wavelength range at about 90% transmission for common clear polymers.

You also get additional loss from Fresnel reflection which is tied to the refractive index of the material and other more complex issues involving angle of incidence and polarisation (glass @ n=1.5 ish is about 4% loss for normal incidence).

I would guess 15-20% efficiency loss overall? You could do a test with a multimeter and appropriate load.

Temperature may also be a factor, solar PV efficiency decreases with ambient temperature. Having a panel in a map case will increase the operating temperature.

Good point well made.  Clearly it was just bloody stupid to try to make an analogy with a greenhouse in the first place, so I can only apologise for bringing them up at all.

Map case won't be the issue here. Constant shading, changing sun angle, poor placement, and general small panel size will be far more limiting IMO. 

That's OK. When I worked at the Ortlieb Institute we had to solve all sorts of daft @rse questions. Do you know how many map cases are required to build a hang glider?

Did you ever figure out the answer?

No idea at all, but if you develop a map case that doubles up as a decent bivvy bag while you're working on it you might be on to a winner.

No. All our research funding went on putting solar charging panels inside our map cases. It's probably the most pressing problem in map case research today.

perovskite based panels

I can only guess that it's been a long winter so far ?  Absolutely nothing in the quarries in any sort of condition at all ?

Dave

He hardly wants his panel to get a sun tan though, does he?

What he ^^^ said. 👍