Ha, I did it. Hood solar

[Paddy]

Always wanted to mount a panel on hood, but until these semi rigid models came out I couldn’t do it. They are a thin skin of aluminum so they don’t suffer issues with wind and dirt like the plastic flexible ones.

Anyway this is the first step toward my camper conversion so I’m stoked about that.

 

[Kingsize24]

Awesome! Which ones did you purchase? Got a link?

 

[Hillbilly Heaven]

Nice Move Bumper

 

[Paddy]

I’ve had them in my shop for over a year. I got a good deal on them from an eBay seller. I tested them in full sun and they put out more than advertised amps! The key search word is “semi flexible aluminum”. Also sometimes called aluminum substrate solar. They are even rated to walk on (carefully).

Thanks on the bumper. It came out okay. I still think they should have cut their name in backwards so it reads right in a rear view mirror. Then again who uses those these days. The rear bumper is kinda goofy, and it didn’t suit the stock bed, but when I changed to the service bed it suddenly looked great. Just don’t try to stand on it, you’ll fall for sure.

 

[Bubblegoose1]

Looks good. Keep us posted on hood heat results. I have been considering the same install. Heat, without air space between the hood and panels, has been a concern.

 

[Paddy]

Yes I’ve mulled that over and I contest that they will run cooler on the hood than on roof. The roof has insulation or trapped air directly behind the sheet metal, therefore no heat that gets through the panel will be able to dissipate. The hood however is open inside. True the engine is hot but only when I don’t need the solar to work. When sitting there is more air flow and no windows to let in heat. Experiment: park car in sun and let engine cool completely. With interior good and hot from sitting, take temp reading. Now take reading under hood. I bet it’s considerably cooler underneath hood, but I haven’t done the test admittedly.

But the biggest issue with roof mounting is that they will be blocked greatly by any gear that’s mounted where the hood is always conveniently clear. You could slip a thin sheet of foam under the panels if you wanted sinsulation, or even mount with some air under if you really wanted, but these aren’t really meant to be mounted like that I don’t think. But, I wanted to see how they would work like this. I roof mounted one of these panels on my sprinter and it worked out really well. They are the best compromise between heavy glass traditional and soft floppy flexi types.
These also add zero weight and bulk, obviously.
If you’re lucky you can find them in various sizes for 1.50-2.00$ per watt.

 

[luthj]

I would agree that the hood is a good spot for them. Less likely to be shaded. Even a 20% shading of a single cell will make it a current consumer, and can drop panel output significantly. I would not put insulation below them, air gap , or bonded to a conductive surface is best. These cells will get hot in direct sun. Cooler cells mean more output!

One of these panels on an AL sheet could have a slotted rack/bracket on the roof (very low profile, AL extrusion?). This would let you pull them off if your parked in the shade, or if you have gear on the roof, etc. A good compromise between permanent and portable panels.

 

[Paddy]

And just think, you can angle them by popping the hood! Lol. Which might sound funny but you know what? I was putting it into effect in the evening sun just tonight while wiring them under hood. I’m tempted to mount these to piano hinges so they can tilt. Then again, KISS. They beauty if using the hood is that it’s not useable for anything else so it’s really no down side even if the panels aren’t max efficiency potential (but I think they are)

I figure my roof will always have kayaks on it and those things can block a lot of sun. Like, all of it lol. Panels that move around with the sun are always going to return massively better results, but, ads another significant chore to ,y “relaxation”. So, these panels will hopefully do some good while not taking me away from what I love to do best, which is nothing! Tested today and with overcast sky and parked under a tree, in other words indirect light, they were still pushing more V than the battery had in it so, they are already paying themselves off.

 

[Yroundrdn]

I'm amazed at the quick advances they are making on these. I was at the Overland Expo last weekend and they had some that were so durable you could drive over them, drop them or walk on them. Another vendor had one that rolled up in the awning.

 

[DaveInDenver]

I can see the logic of this from the solar perspective. My question is if they'd reflect or cause a glare. I could see them being a problem driving into a sunrise or sunset.

 

[Paddy]

They can’t be any worse glare than was already present, because they follow the same shape as the hood and in fact being black they should have less glare.

 

[Paddy]

I wonder if I could just wire a second charge controller into the panels in parallel with the engine batt controller to charge the House?

 

[Paddy]

The way I’ve done it in the past is to hook panels to house batt only and hook the engine batt to house with an ACR and this works well for function while in use, but doesn’t address a dying engine batt while on long term park.

 

[luthj]

Many acr are bidirectional. So a charge source on either will trigger a combine. There is also the trick-L-start. This is a battery to battery trickle charger that keeps your starting batt topped up from the house.

 

[Paddy]

Here’s the controller I’m using under the hood. It uses mppt technology which was new to me but it’s basically as I understand it a voltage boost that can bring up lower voltages during partial light or low light to the 13v we need for the batts. It’s also waterproof which I wanted for under hood install. Seems to be working but I haven’t really tested it in full sun. The truck sits in tree shade when parked.