Solar under the front windshield

basing110

Observer
Looking at doing some solar panels and have read some reviews of people putting small 7 -20 watt solar panels on their dash and showing .75 V drop difference from on the dash to in full sunlight.

Has anyone tested this with larger panels? Or can you?

I am debating on getting a flat foldable 100 watt panel and putting it inside my windshield while running my fridge. This would save me from taking up valuable roof space and i could use it from vehicle to vehicle and in populated areas with a little security. Once out in the boonies camping i could still use it in full sun.

I can almost always park facing a certain direction depending on time of day to get the most light possible given a setup like that.
The vehicle front winshield tinting if any can change the output.

I know it would be better to just mount a panel to the roof but i am looking for other possibilities and after searching the net for any real world tests i have come up with next to nothing.
 

rayra

Expedition Leader
Not sure what kind of 'tests' you are looking for. Yes there's a slight drop through the glass. There have long been (25? 30? yrs) small clamshell-design solar panels meant to be used as battery tenders in stored vehicles. Typically they plug into the cigarette lighter. They typically generate around 1Amp

Messing around wtih my own 100w folding kit, I think you'd best re-evaluate your inside windshield plan. Even if you get it in there, you'll need to somehow support the upper end. And the backs of panels are exposed within their aluminum perimeter frames. So if the panel is laying on your steering wheel you might break the panel. Then there's the corners of the panel digging on the dash etc. And shadows cast on the panel by rear view mirror, dash cam or cellphone mounts, A-pillars, which in some panel designs may hinder power production a great deal.
I've got large vehicles and I wouldn't even want to try wrasslin a 100w panel into such a position

If you want to go with the dash, I'd suggest some sort of soft / roll-up panel. Too, even at the lower amp outputs - anything less than the rated draw of your fridge - you'll at least be generating SOME power and extending your battery life under such a sustained load.
 
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Ducky's Dad

Explorer
I tried three different small NOCO panels on two different vehicles, with zero success. These were panels specifically sold as dash-top panels. These were a complete waste of money in my case.
 

rayra

Expedition Leader
was driving around in my Suburban later in the afternoon today and while sitting in traffic and looking out my windshield I thought of this so snapped a pic. There's just no reasonable way to position a 100W panel in this space, not without some complications and just plain looking goofy as hell.

Suburbanwindshielddashspace.jpg


If you really think you want to do this, OP, I suggest you get a piece of cardboard cut to the size of your intended panel and wrestle around with it some.
 

Red1

HERO
Looking at doing some solar panels
and have read some reviews of people putting
small 7 -20 watt solar panels on their dash
and showing .75 V drop difference from on the dash to in full sunlight .

Has anyone tested this with larger panels ?

Or can you ?

I am debating on getting a flat fold-able 100 watt panel
and putting it inside my windshield while running my fridge .

This would save me from taking up valuable roof space
and I could use it from vehicle to vehicle
and in populated areas with a little security .

Once out in the boonies camping I could still use it in full sun .

I can almost always park facing a certain direction
depending on time of day to get the most light possible given a setup like that .

The vehicle front windshield tinting if any can change the output .

I know it would be better to just mount a panel to the roof
but I am looking for other possibilities and after searching the net
for any real world tests I have come up with next to nothing .

We have used those mini solar chargers to keep batteries charged ~ you will need a lot more to run your refrigerator & keep your milk cold . . .

GMC solar.jpg

Our youngest son installs solar @ www.Instagram.com/WiseYoungin . . .
 

rruff

Explorer
I am debating on getting a flat foldable 100 watt panel and putting it inside my windshield while running my fridge. This would save me from taking up valuable roof space and i could use it from vehicle to vehicle and in populated areas with a little security.

Have you thought about mounting one on the hood? Flexible or not, either would work. Solar panels are cheap enough now, I wouldn't worry about them getting stolen.

1f1162bb4f2ff0aa69ae7dc910f5c087.jpg
 

dwh

Tail-End Charlie
Even if it fit, it's not a great idea. The glass in solar panels is coated with an anti-reflective to minimize the photons ricocheting off the glass. More photons crashing into the solar cells' electrons equals more power.

Adding another layer of (warped, bent) glass, without an anti-reflective coating is going to reduce watts harvested by a significant amount.


http://2manytoyz.com/solarlexan.html
 

calicamper

Expedition Leader
Your biggest issue is lost generation due to heat. Hot car sitting in a hot spot you'll loose 50% of what little generation a small panel on the dash would generate 10watt panel at most with 30-50% loss from high temps your looking at about .5 amp generation. Not worth it.
 

4Roamer

Member
I saw a Taco with a flexible panel mounted to the hood. He had painted the center section black so, it didn't stand out that much. Looked good.
 
Not to jump in on an old post, but much of the solar energy that is generated is coming from the UV/IR spectrum which is not penetrable through glass.....hence why thermals can't see through glass! Then there are the refractive and reflective effects of newer glass in most vehicles for safety purposes and all that hoopla.

Voltage drop through a windshield is counterproductive to any possibility of reliable charging since the heat, UV/IR angles, and all of that would have to be completely perfect to provide optimal charging conditions.

Most people will tell you that flat-mounted panels even on the roof are not ideal over directly positioning panels into the sun; the difference is, the roof mount is the best option available for on the move solar.
 

workerdrone

Part time fulltimer
I saw a Taco with a flexible panel mounted to the hood. He had painted the center section black so, it didn't stand out that much. Looked good.

Might have looked good but probably didn't work at all - painting over even a couple of the cells would pretty much kill the output of that flexpanel
 

Wallygator

Adventurer
The flexible panels already have a high heat issue when flat mounted which causes efficiency drop and will fry cells on some panels. I would be afraid mounting it to the hood would greatly increase that with the heat from the engine rising through the hood.
 

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