I dont see how you can be a fan of EVs and not think this is a great idea. I know the typical criticism is that they are not very efficient, and generally only add weight and maybe a few miles in range.
As you may have seen from my earlier question a little while ago, I am beginning an EV transformation with a 1986 Toyota Pickup (although for some reason at the time I thought it was a ’94… it isnt), and I am using a neighbor as my guide.
He took an older Ford Ranger frame from a junkyard (for free, I might add). It had the frame (very little rust, gotta love the sonoran desert), manual tranny, and axles. He had to get damn near everything for it. Anyway, the donor car was in a rollover and he had to rebuild the roof, so he figured he might as well put some solar panels on it. After the car was finished, with about $ 30,000 invested and somewhere near 120 mile range, he decided that he really liked the look (he is an electrical engineer, he built the car mostly as an “ad” for his company) of the solar panel roof, so he decided to go all-out and put another panel on the hood and a solar bed-cover. It added another 10 miles in range for an additional $ 3000, which was mostly spent in custom fabrication so the car would look nice.
Due to this, he is actually going to take another frame he has from an older F150, and remove the bed entirely, and put a massive panel on the back, and put lots of batteries underneath.
His brother was in large part his fabrication expert, since he owns a car body shop and did quite a bit of the legwork for the Ranger. He plans to make a very durable solar panel which will actually house the batteries as well, and simply use it as the back.
All in all, generating more range seems to be the pressing issue with EVs. My gas-sucker can go hundreds of miles without needing to be filled, so the more EV range increases, the more popular EVs will get. So why not put a solar panel on?
More Pages:
- Solar Energy: DIY Solar Panels? From Scratch? (6/2/2012)
- I’m sick of all the BS on gas prices and cars not going solar/gas free……?
- Solar Panel: What Solar Panel Is Needed To Charge Four 12 Volt Batteries? (2/25/2012)
- Solar Panel: What Type Of Batteries Do I Get For A Solar Panel? (1/16/2012)
- Solar Power: Looking For Mobile Solar Power Solution? (7/9/2012)
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You have told a good story with lots of interest but I am not convinced. I think solar panels are great, some other ways of generating solar electricity may be even more efficient, but I am not sure that the numbers work to put them on the vehicle. In a nutshell my concerns are cost and efficiency. Your neighbor spent a lot of money for those solar panels and it makes sense as advertisement for his business, but could he have done better.
First efficiency: You live in the desert. Your insolation levels are probably uniquely some of the best in the country. Average insolation for the year might be as high as 6 KW-hr / sq meter / day. For a horizontal flat plate PV collector. You can look up values here: http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/serve.cgi The efficiency of the solar panels would be low for flexible panels 6% up to a high (with a high cost) for some rigid panels of about 24%.
At an average a 15% efficient panel is going to get you ( .15 x 6 =) .9 KW-hr / day This site gives dimensions of a later year Toyota pick up as 199″ by 66.5″ which translates to a total of 8.54 sq meters for the total surface area of the vehicle including all glass and the entire bed. Covering it with solar panels would give you a total potential of about 7.68 KW-hr / day.
In order to get his 120 mile range I am willing to guess that extra batteries were used. Perhaps his battery capacity is 45 KW-hr which would give a usage of .375 KW-hr / mile which would be very very good. (The leaf gets .34 and the Miev gets .39 while the Tesla roadster is closer to .22) A 40 mile day average will then require (40 x .375 =) 15 KW-hr / day. It looks like the expense of covering the vehicle might get you half your days usage or enough power for an additional (7.68/.375=) 20.5 miles.
But what if you parked those same panels on the side of the barn pointing south at the proper angle. They your average insolation level would be perhaps 17% higher.
You want more range? Then just add more batteries. Or perhaps better add some mix of batteries and solar panels. If solar panels cost $ 10 a watt and when you divide by the effective solar hours in a day you might end up with a 1000 wat system on your car. The cost would be $ 10,000 for these solar panels. Lithium batteries cost about $ 400 / KW-hr so the same 7.68 KW-hr of additional battery capacity might cost you $ 3072. And that range is not dependent upon daytime driving/ time of the year and other variables.