Replacing alternator with solar panel array on roof?

[gascort]

Originally Posted by Tourigjm

I've heard that the next gen prius will have a solar system to run all the "non essentials" as an option. so you are definitely not the only one with this idea. How long do you estimate it will take to recoup the price of the panel/bodywork in fuel savings?

I really don't have an answer for you; I'm unsure of the amount of mpg savings for this type of setup. If I manage to save 4 mpg, which is ballpark of what I hope for, it factors to:
15,000 miles/year / 40 mpg = 375 gal *$4 = $1500 fuel costs
15,000 miles/year / 44 mpg = 340 gal *$4 = $1360 fuel costs
I think I can get the equipment for around $300, and do the installation myself. It should take about 2.5 years to pay off.
If my mpg values are better, payoff will be faster, and if lower, then longer...

[idiom]

Originally Posted by blackjackel

Has anyone thought about doing this? You could get all your electrical power from the sun isntead of your engine/gasoline...

How about this?:
12-Volt Solar Battery Charger Car/Truck/Boat (w/Clips) - eBay (item 270271348878 end time Sep-08-08 11:00:00 PDT)

http://i7.ebayimg.com/03/i/000/db/f8/a744_1_sbl.JPG

[BrianAbington]

I saw a prius online that had solar panels to recharge the plug in battery pack. The cells were set flush and curved to the roof so it wouldn't affect aerodynamics.

Think about this...plug in hybrids with solar panels on the roof...so they recharge them selves entierly as you drive. Then when you get home or to work, or the mall...etc you plug them in to power cords in the parking lot and they put power into the grid!

yeah it wouldn't be much...but look at how many cars are in the lot at your local mall. That would add up.

[jamesqf]

Originally Posted by Binger

Think about this...plug in hybrids with solar panels on the roof...so they recharge them selves entierly as you drive.

(Sigh) Do the math. IIRC, the energy of sunlight at 45 degrees latitude is approximately 700 watts per square meter - and that's meter perpendicular to the sun, on a clear day, at noon, in full sun. Solar panels on a car are not often going to be any of these, but ignore that for now, and figure that the sun's providing about 1 HP per square meter.

A solar cell that has 20% conversion efficiency is pretty darn good, so that's 0.2 hp per square meter of solar cells on your car. How many square meters can you fit? 5 seems pretty high, but it makes a nice round number. How far and how fast is your car going to go on one horsepower? And realistically that's the absolute max you're going to get. Most of the time you'll be getting much less.

but look at how many cars are in the lot at your local mall. That would add up.

Why not do something more practical instead? Put up shade structures in the parking lot, and cover their roofs with solar panels. That way they can be oriented to face the sun, and generate whenever the sun is shining, not just when your car happens to be in a sunny spot.

[cfg83]

jamesqf -

Originally Posted by jamesqf

...


Why not do something more practical instead? Put up shade structures in the parking lot, and cover their roofs with solar panels. That way they can be oriented to face the sun, and generate whenever the sun is shining, not just when your car happens to be in a sunny spot.

Bingo. That's what I want :

Solar e-Clips - Parking Lot or Power Plant?

Close to half of the urban landscape in the United States is dedicated to automobiles and about 20% reserved for parking alone. With land becoming an increasingly scarce resource, attention has turned toward making parking lots more productive urban features, serving multiple functions rather than only providing space for cars that sit idle 95% of the time.

Parking lots provide an unparalleled opportunity for generating clean, renewable energy through installation of photovoltaics (PV). PV carports provide highly desirable shade for parked cars and can help improve air quality by reducing parking lot temperatures, thereby reducing hydrocarbon emissions from gasoline that evaporates from leaky fuel tanks and worn hoses.

CarloSW2

[Newton]

Found solar modules for $0.83/watt. This seller commonly has modules for this cheap. Only downside is you have to do the labor yourself but that's why they're so cheap. I figured that on top of my metro I can fit 102 of these 3x6 modules generating about 183watts max.

Since my metro doesn't agree with 12v and requires the 14.5v to run properly I figure I can put two 12v deep cycle batteries in series to produce 24v then use a voltage divider circuit to bump it down to 14.5v that would feed it to a 12v battery for starting and to run the cars electrical. The solar array would be wired properly to feed directly into the 24v pack.

What would be a good current to design the voltage divider to sustain? probably over 163watts for my metro going by the experiment with the blackfly.

[ConnClark]

I think the weight of the two deep cycle batteries would offset any gains on a metro.

[TroyRank]

First Post-

Here's another approach to this idea:

I have an old saab900 which has a bad crank pulley (harmonic balancer) Which I will fix one of these days. Since I ride my motorcycle most of the time I havn't got around to fixing it.

The crank pulley is what allows all the "Accessories" to run (water pump, power steering pump, AC Pump, Alternator). I would imagine these things all added up together would be a significant load on the motor.

What if I was to create a Hybrid, which would utilize a small amount of batteries (perhaps lead acid, perhaps Nicd) which could run the accessories with the use of a small 12V brushed DC motor.

Hell, I could remove the harmonic balancer completely...

Naturally you would have to charge the batteries at night, but it wouldn't be very hard to get enough battery power to run the car for any given day.

I wonder what kind of fuel economy gains could be achieved from a setup like this?

Should I try it?

[TroyRank]

P.S. a Solar Panel could be added to help ....:-D

[Shawn D.]

Originally Posted by TroyRank

Hell, I could remove the harmonic balancer completely...

Naturally you would have to charge the batteries at night, but it wouldn't be very hard to get enough battery power to run the car for any given day.

I wonder what kind of fuel economy gains could be achieved from a setup like this?

Should I try it?

No, you shouldn't try it. First, the harmonic balancer is more than a pulley base -- it damps crankshaft oscillations that can damage the engine.

Second, to run all those accessories "for any given day," you'll need a significant (not "small") DC motor and batteries. Sure, it won't be like creating an entire EV, but you'll need to have a control system to monitor and adjust speed for the water pump.

On second thought, go ahead and try it...