# Solar powered car?



## fishhead (Jul 19, 2006)

Would it be possible to put up a reasonable amount of solar collectors and use that stored energy to recharge the battery in a commuter car for a 40 mile daily commute?

My car gets 35-40 mpg and I probably spend about $30 a week 52 weeks a year. My yearly gas costs me about $1,600. Multiply that by 5 years and it starts adding up.


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## wy_white_wolf (Oct 14, 2004)

Your propably looking at about 5kw to 10kw worth of panels for starters. Really just a SWAG until you get the car and know how much it takes to charge it.

Hopefully you can charge the batteries in the car direct, but if the car is to be away from the panels in the daytime you will need a set of batteries to charge while the car is away.


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## mightybooboo (Feb 10, 2004)

With lead acid batteries it would take 14-16 batteries or so.

Or about 8 L-16 batts equivalent.Ballpark figures.

Need to figure how many amp hours at 50% discharge at least,somewhere in that area.

Try looking up the Rav 4 electric or the Ford Ranger electric,might be able to get your info there.


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## OntarioMan (Feb 11, 2007)

Are you looking to simply remove the alternator on a fuel powered vehicle? Removing the alternator on a fuel powered car will only save maybe 4% to 6% - which equates to less than $100 per year for you. 

It may pay to simply get a more fuel efficient vehicle - like a Geo Metro. A stock 5 speed Metro may hit 55 mpg if you drive it properly on the highway.

If you're paying $1600 at 37.5 mpg, you'd pay around $1100 at 55 mpg, a savings of $500 per year in fuel.

Checkout http://www.metrompg.com for lots of great info. re. fuel savings. 



fishhead said:


> Would it be possible to put up a reasonable amount of solar collectors and use that stored energy to recharge the battery in a commuter car for a 40 mile daily commute?
> 
> My car gets 35-40 mpg and I probably spend about $30 a week 52 weeks a year. My yearly gas costs me about $1,600. Multiply that by 5 years and it starts adding up.


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## fishhead (Jul 19, 2006)

I was just wondering out loud if it would be reasonable to charge batteries during the day and then transfer that charge to the car each evening or if it would take $20,000 worth of solar cells.

The vehicle would be 100% electric.


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## wy_white_wolf (Oct 14, 2004)

One of the main expenses with electric cars is the batteries. They also wear out from discharging them over and over again. So having a second set of batteries to recharge the first set is going to double (at least) your battery cost. You would be farther ahead if you swapped battery packs everynight. This would make your batteries last longer.

Just ruff figuring.

20kwh would be about the minimun amount it take to charge any of todays car. At a winter average of 4 hours a day to charge that would be 5kw worth of panels.

At $4 a watt that's $20,000 in panels alone. 

I think a more realistic size would be in the 10kw range for panels.

A few good sites on electric cars:

http://www.evalbum.com/build.html

http://www.evadc.org/build_an_ev.html


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## ace admirer (Oct 5, 2005)

no.


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## Ed Norman (Jun 8, 2002)

Last time I came thru MN it was gray and cold and cloudy, with a short day. You wouldn't get much charging done. So you would need to either plug in or keep a gas car for winter driving along with the electric.


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## MELOC (Sep 26, 2005)

here is a neat little project if only you lived a bit closer to town. i wish this guy had given more detail about the "stuff" in this vehicle. 

this is a youtube video..so beware those with dial-up.

[ame]http://www.youtube.com/watch?v=M0JNohHaqM4[/ame]


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## sgl42 (Jan 20, 2004)

why did you mix the 2 problems, ie, electric car & solar? I'd suggest you break it into 2 problems -- (1) does it make sense to have an electric car? (2) Does it make sense to charge the electric car from solar power instead of the grid?
--sgl


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## mightybooboo (Feb 10, 2004)

MELOC said:


> here is a neat little project if only you lived a bit closer to town. i wish this guy had given more detail about the "stuff" in this vehicle.
> 
> this is a youtube video..so beware those with dial-up.
> 
> http://www.youtube.com/watch?v=M0JNohHaqM4


What a totally awesome Man.

Thank you for sharing.


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## Esteban29304 (Apr 29, 2003)

I would work with trying to get the very most MPG out of you present car. 35-40mpg is already good, but most of us can increase our mpg by 10-15% just by a few alterations. Look over these 2 websites for info, try their suggestions [ some ARE extreme ] & see if that makes you happier.
www.gassavers.org

www.cleanmpg.com


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## fishhead (Jul 19, 2006)

I do conserve fuel ie. set cruise on 57, start slowly, keep tires pumped, plan trips, etc. but I'm convinced that gas prices are going to continue to climb (best case) and could easily spike in a matter of weeks in the future.


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## OntarioMan (Feb 11, 2007)

I agree. The more fuel efficient your vehicle, the less impact the rising cost of fuel will have on your pocketbook. 

Some of the mods that folks do to increase their fuel efficiency are extreme - but there is nothing more extreme than an all electric vehicle using solar panels to recharge the batteries - and the reality is, that it will be many years before an electric vehicle is as convenient or as cheap as a fuel powered vehicle.

Those are great websites.



Esteban29304 said:


> I would work with trying to get the very most MPG out of you present car. 35-40mpg is already good, but most of us can increase our mpg by 10-15% just by a few alterations. Look over these 2 websites for info, try their suggestions [ some ARE extreme ] & see if that makes you happier.
> www.gassavers.org
> 
> www.cleanmpg.com


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## WisJim (Jan 14, 2004)

It is generally considered that .2 to .5 kw-hrs per mile is a reasonable ball-park figure for electrical consumption for an all-electric, battery powered car. A typical PV panel might produce 10 to 13 watts per square foot. If you lived where the equivalent full sun hours was 4 hours a day, you would get 40 to 52 watt-hours per day per square foot of PV panel. Let's say 50 for easier figuring. (I am using 4 full sun hour equivalents as that is the figure for Western Wisconsin, where I live, and probably close to what you can expect. This isn't the total hours of sun, but the equivalent number of hours of full PV panel output that you can expect on an annual average.)

So, if your all-electric car uses .5 kw-hrs per mile, you need 500watt-hours (0.5kw-hrs) to go one mile. To produce that, you need 500 divided by 40, or 10 square feet of PV panels to produce that amount of electricity in an "average" day. A Kyocera KC130 PV panel is almost exactly 10 square feet, and produces 130 watts peak output. I have 12 similar panels (older ones rated at 125 watts each) that produce about 6 kw-hrs of electricity per day on the average, year around--some days almost nothing, somedays a lot less. PV panels set up to do nothing but charge your car battteries might cost $6 to $8 a watt, or more, installed. If my PVs did nothing but charge the batteries of a simple electric car, I could drive 10 miles to 15 miles a day on that power. These figures are estimates and a bit of guess work, as power usage in electric cars varies all over the place. So far, I'm not sure if these figures hold for "real life", but ask me in a year. Our 1976 Citicar might be on the road by then.

Edited to correct math errors


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## SolarGary (Sep 8, 2005)

Hi, 
WisJim's updated numbers look good to me.

If you take the 40mpg you get now with the car on gasoline and convert that to the equivalent KWH per mile, it comes out to 0.9 KWH/mi -- electric cars are more efficient, so you might get something like the 0.5 KWH/mi that WisJim suggests once its converted.

One alternate approach is to scale the vehicle way down to reduce the KWH per mile, and then take the PV panels with you so they can charge at work:
http://www.builditsolar.com/Projects/PV/pvscooter.htm

Newer design electric vehicles with lighter weight structure and battery technology, AC motors and controllers, ... should do better and require less PV to charge them.

There is a good article in Home Power issue 117 by Kevin Johnson on his EV conversion and PV charging system. By cutting driving down some, and through electricity conservation in his house, he manages to power both his EV and home on a 3 KW PV rig in a sunny location. But, he is not faced with a fixed commute as you are.

WisJim -- Hopefully you will let us know how the Citicar comes out?

Gary


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## ed/IL (May 11, 2002)

Perhaps you could plug in at work.


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## fishhead (Jul 19, 2006)

Thanks for all the info!

If (HA!) the price of gas keeps going up and the price of solar cells keeps going down this looks doable. Add to that improvements in batteries and we might start seeing all electric solar charged commuter cars before long.


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## SolarGary (Sep 8, 2005)

Hi,

Here is a 50 watt-hr per mile EV!

http://www.evalbum.com/1418

1 penny per mile, 40 mile range, $9300 new, and really good views 

Gary


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## fishhead (Jul 19, 2006)

That looks like a good city car.

If I drove 45 mph they would run me over. Even at 57 I sometimes stack'em up behind me.


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## wy_white_wolf (Oct 14, 2004)

That'll work great in the northern Minnisota winters.  

While the owner of that one claims 50 WHPM, I couldn't find that same claim on the dealers(?) website

http://www.harveyev.com/BugE/


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## mightybooboo (Feb 10, 2004)

Its a step.I like how he is advancing to Li ion.


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## Esteban29304 (Apr 29, 2003)

It is not feasible in many parts of our large country, but some people drive from their homes to a parking area, & catch public transportation from there, [ Park & Ride ] to save some gas. Others ,, including myself, ride a bike or walk, for short errands. Carpooling is another alternative. I feel that there will never be " ONE " cure for our oil dependancy, but we ALL must do something .


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