Solar panels by IKEA

[oil pan 4]

To charge a lead acid battery you need at least 16 or 17 OCV (open circuit volts). I hooked up 15.5 OCV worth of panels to a battery last month and it pushed almost no power into the battery.

Originally Posted by dieselbeetle

Ok, now that we've established the fact that it CAN assist, how much?

How much roof you got on your car and how deep is your wallet?
Those are the only limits I can think of.

I plan on building two 8 amp 17v panels to put on the roof of my suburban and if I get enough power out of them during day light hours I will experment with running with no alternator belt. I have all the materials, just need the time to do it.
If (not very likely) that the solar panels work good I am going to look into building a tool-less alternator belt quick relase system.
If they don't work they will be serriesed up and put to work running a grid tie inverter.

[SwamiSalami]

nice.

Unfortunately, my question wasn't really answered.

I want to know what kind of efficiency gains I can see from adding some solar power. NOT DELETING the alternator. But rather, augmenting its usefulness through solar means.

[NeilBlanchard]

Right, well one of those laminated panels would provide about 5A, enough to supplement an alternator. 15 1/2" x 216" and $447 is a lot of PV material to even fit on a car. I think the best it it do is power some ventilation fans and your stereo.

[oil pan 4]

The wiki here says that in theory every 50 watts of electrical load you remove you can pick up something like 0.55% fuel economy.

[SwamiSalami]

Originally Posted by NeilBlanchard

Right, well one of those laminated panels would provide about 5A, enough to supplement an alternator. 15 1/2" x 216" and $447 is a lot of PV material to even fit on a car. I think the best it it do is power some ventilation fans and your stereo.

Thanks, Neil. I now deem you "Ol' Reliable". Don't worry, it's a compliment. You've done a great deal to enhance my experience as an ecomodder. Hope you never go away.

Anyhow...

I think that if an affordable solar setup was obtained, it would be fun. Fun unfortunately doesn't amount to practical. If I had a million dollars, maybe. I'm infamous for saying "why does it have to pay for itself?", however as a young student of History Education, it becomes more of a question of "How CAN this pay for itself?"

Originally Posted by oil pan 4

The wiki here says that in theory every 50 watts of electrical load you remove you can pick up something like 0.55% fuel economy.

Thanks. If this information is accurate, it would take a lot of surface area to amount to little mpg improvement. With that said, the better your fuel economy to being with, the better your results with this setup would be.

For instance: my 2001 vw beetle tdi automatic gets around 45 mpg. x/45=.55/100 is my formula.

From this, I learn that "theoretically", I should gain .2475 mpg from the solar addition.

Similarly, if Frank Lee's '98 Mercury Sable Automatic recieved the same solar treatment: x/30=.55/100

He would likely only see a .165 mpg gain.

In summary, if you're in the market for a new hybrid, buy one withOUT the solar panel. I say this, because you're paying for it one way or the other. And, while it provides a bit of nostalgia and is quite honestly very, VERY cool, it will likely not amount to significant savings concerning fuel economy or monies.

[SwamiSalami]

I'd rather drive without the radio and using the vents sparingly.

[EdKiefer]

If you run no accessories you could maybe only need like 20-25a and that would go up to 35a once some fans kit in. add lights ,wipers etc and your probably in the 35-45a range depending on car .

[topcat]

If your panels are low quality, low efficiency, there is a high likelihood of the extra mass of the panels reducing your mpg more than any mpg gained.

[oil pan 4]

On the weight side of the house it takes like 50Kg to lose 1% of your MPG.
Aero dynamicly you can lose more than a few % real easy, check out the roof rack delete wiki.
My suburban has such poor aerodynamic features afew low profile solar panels on top wont hurt anything.

[SwamiSalami]

Solar films have come a long way. by using them inside AND out, we may have a solution to this microcosm.

For instance, my beetle's dash is huge.

(I say this theoretically. I have no proof.)