Solar Panels for Auto Applications

[capnbass91]

I've thought about putting solar panels on cars for a while. But I hear the panels are QUITE expensive. As a means around that I thought you could buy a bunch of cheap calculators with a small solar panel on them and take them out and rig them to your car. But that probably wouldn't work very well or at all hahahaha.

[SwamiSalami]

That's interesting that you mention this "calculator" idea. I keep crossing my fingers that I'll come across a school that's discarding their old ones.

It obviously wouldn't be cost effective to buy calculators for this use. But, hey, if you came across a lot of them for cheap or even free, it would totally be worth it.

[capnbass91]

Just gotta think outside the box!

[Fat Charlie]

Cars are a great place for solar. The military's been using them for years. This was my driver tracking mud all over the "No Step" sign, but the little solar panel shows up pretty well. They get parked for long periods, sometimes with the radios on all the time. No problems, at least with the batteries.



Don't scoff at something being "only" a trickle charger. I slapped one of these on my shed once the snow melted and by the time I needed to use the mower it worked. Usually I have to drive out to the shed or push the mower back to the house so I can jump it the first couple times I use it. This year it started right up- not too shabby for $25.

Depending on your usage and where you park during the day, a DIY panel could replace your alternator: flexible solar panel - Google Search. I don't think it would help me too much, but you could probably turn your whole roof into a panel without having to know too much about electricity.

[California98Civic]

Originally Posted by Fat Charlie

you could probably turn your whole roof into a panel without having to know too much about electricity.

"The General rule to calculate the average charge time:

"Take Amp/hour rating of the battery and Divide by the charger rating (in amperes) and then add about 10% for the extra time to top off the battery, i.e. Assuming You have a typical full size auto battery, it is about 50 amp hours.

"To Calculate how much time You’ll need to charge the battery with a 15 Watt solar charger You’ll need:
1. Calculate the Ampere per hour of the charger: 15 Watts /12 Volts = 1,25 Amperes
2. Calculate the division: 50 amp hours / 1,25 ampers = 40 Hours of direct sunlight
3. Add 10%: 4 hours"
(retrieved from here: How to Use 12 Volt Portable Solar Powered Battery Chargers)

Seems useful. Maybe use a 100 watt charger, like this pretty expensive thing:
100w 12v,Semiflex solar panel,thin 2.5mm,Waterproof ! - eBay (item 260771192187 end time May-18-11 20:59:20 PDT)

This panel would nearly cover my whole roof.

[spacer]

After seeing a string of one-line non-posts, then the above advertisement, I'm reminded of a certain potted meat product...

edit.. the ad post was removed, so this post is in no way meant to describe anything else here.

[some_other_dave]

Spacer, there is a little exclamation-mark icon () in the lower-left corner of each and every post. If you click that, it will alert The Management to a problem with a post. Please use that button to report SPAM.

-soD

[spacer]

Oy, was just thankin' ya here, but it's off topic, so feel free to delete it.

[Andale]

Originally Posted by Fat Charlie

Don't scoff at something being "only" a trickle charger. I slapped one of these on my shed once the snow melted and by the time I needed to use the mower it worked. Usually I have to drive out to the shed or push the mower back to the house so I can jump it the first couple times I use it. This year it started right up- not too shabby for $25.

I don't mean to sound like I'm scoffing at the idea. I love trickle charger solar and think they should become a standard. I t would be worth it for car companies to add a strip of solar in the dash of every new vehicle, but I would bet we never see it for ... well... a lot of dumb reasons mostly to do with hurting future sales by removing built in obsolescence.
If every vehicle had a trickle panel then we'd rarely find ourselves trapped and in need of a jump, but once you did you could be certain the battery was VERY DEAD. This is assuming that the car is smart enough to turn off the high wattage stuff.

I only said what I did before to imply that I don't think there are any worthwhile applications other than trickle charging. Does the cost of replacing the alternator with a car-length coating of solar materials equal out in gas savings within 10 years. Doesn't that much material add up to more weight than an alternator anyway. You reduce drag on the engine but add weight to the wheels and possibly deform the airflow over the vehicle. I just don't see it as a cost-worthy application of solar. I love to see experiments so I would never put down anyone who tries that sort of thing, but I will be practical and ask questions.
I still think we (as in everyone, not the U.S., not the ecomodders) need to find a way to start sheeting the top of semi-trailers with solar panels and convert all the trucks to run heat/air off that. Do you know how many states don't make it illegal to idle a semi while it is parked? I've talked to truckers that say they've sat at idle over 24 hours just to keep the truck warm. Some trucks are built smart and cut on/off, some have generators (which are usually gas and that is very funny to me).

Sorry, my 2 cents/rant is now complete.

[Mr. Previa]

Solar is not a bad idea if you have an understanding of the abilities of your application. If your car sits in a parking lot for hours a day, why not use some of all that free energy.

I am pretty sure that most of us here do these mods in part to do our part to help the environment; not only for financial reasons. Personally, I would rather spend my money on anything but OIL!!!

As some one has all ready mentioned, don't under estimate a trickle charge. In my case, pull over 300 watts a day. Usually more than that, but some times less if it is raining/cloudy. That is at 4 to 5 amps. - I use my system to trickle charge my deep cycle that I use in place of my alternator.

Depending on your vehicle, it would not be hard to remove or add your panel. In my case, I used the existing roof rack. It just bolted down to the existing fastener areas. - Probably got real lucky.

Another nice thing about having panels on your roof (elevated ones like mine) is that they help keep the cab cooler by blocking the sun, therefor I don't have to run the A/C.

Now just to be level here, though I have proven the application in a past vehicle, I am still building this for my current vehicle. I hope to be done in a couple of days.

I would eBay for panels and/or check out Harbor Freight. I did both. I found a nice panel for the Previa on eBay and I have a Harbor Freight setup on my barn. Good prices too.

Any who, sorry if I ranted and I did not intend to question any ones opinions. I am simply sharing my personal experiences.

It is a great project to under take. Remember to have fun!!!