MLucas
Posts: 833
Joined: Thu Jun 07, 2012 8:52 am
Location: Niagara on the Lake, Ontario, Canada

Re: solar on the car roof

Mon Jul 23, 2012 4:34 am

Off topic, but...what a neat car! I love that paint job. What is that like to drive and do you still have it?

Like Dylan...I went electric.

  • Purchased: June 29th, 2012
  • Mileage on June 29th, 2013 - 25,431 km / 15,802 miles
  • Mileage on June 29th, 2014 - 51,286 km / 32,616 miles

List of Oil Spills: http://en.wikipedia.org/wiki/List_of_oil_spills

PV1
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Re: solar on the car roof

Mon Jul 23, 2012 4:10 pm

The batteries I found are 160 Ah LiFePO4 cells, and you would need 16 cells at $207.92 each. A 240 watt solar panel is $500, and the inverter is $500. This setup would give you 8,192 Wh of extra electricity, plus .5-1 kWh from the panel, totaling 8,592-9,192 Wh of extra electricity, giving you slightly more battery capacity than a LEAF. Although, this extra storage cannot be accessed by the car while in motion. The power can only be transferred to the car through the inverter, through the level 1 EVSE, and then to the onboard charger while you are parked. So, the question is, at the same price as a LEAF SV, would you attempt it? I probably would, because the i is easier to manage in heavy traffic because visibility is better. My circumstances at the moment is I drive 40 miles to work, 30 of it on the highway at 60-65 mph, sit for 10 hours in an unshaded parking lot, and drive home. There are no plugs that I can find, so having this setup would help, while also making a statement. Of course, you'd also need a wall charger for the second battery pack if you plan to use it everyday, like I would, so you can recharge the second pack overnight. You could also manage a window fan or something to keep your car cooler while parked, powered by the solar panel. And if anybody doesn't know, the LEAF SL does have a solar panel on it, but it is a little 5 watt panel on the back by the top brake light meant to maintain the 12 volt aux. battery, adding no range to the LEAF. Wasn't meant to.

So, doable? Yes. Practical? Most likely, unless you don't need the range extension or have a plug handy to charge from. Affordable? About the price difference between the LEAF and i. The LEAF and the i have about the same economy on the highway, with the i having the city advantage, so you'd probably get better range than the LEAF, given that you have enough time to deplete the secondary pack.
:idea: :idea: :idea: :!: :!:

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TaosEV
Posts: 68
Joined: Sat Apr 14, 2012 4:06 pm

Re: solar on the car roof

Mon Jul 23, 2012 4:55 pm

Did you calculate the extra energy needed to transport the extra weight around? And what drag you'd add to the vehicle by putting a solar panel on the roof?
=====
2012 iMiEV
2007 Zenn
1998 Honda EV+
1995 GM Impact prototype consumer test driver
... over 60,000 miles in electrics

PV1
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Re: solar on the car roof

Mon Jul 23, 2012 5:40 pm

What is the difference in range with an extra 200 lbs? (Tried to make that sound sincere) As for the solar panel, the frame could be modified to let the panel sit as low as possible, with skirting around it to smooth out airflow. But you're obviously paying an aerodynamic price. But in some people's situation, like mine, you can sacrifice a few miles one way for an extra 18-25 miles for the other way.

Instead of putting a solar panel on top of the car, how about making a windshield shade from Solarrolls? But this kind of strays away from the idea given the price and inefficiency of flexible solar panels.
:idea: :idea: :idea: :!: :!:

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Don
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Re: solar on the car roof

Mon Jul 23, 2012 6:22 pm

You're talking about spending $4500, giving up cargo space, adding weight, complexity and taking an aerodynamic hit for another 25 miles of range which can only be accessed if you leave the car parked for 10 hours, plus you're adding in the inefficiencies of recharging one battery pack from another battery pack via an inverter - Your definition of 'practical' is maybe just a little different from what might be considered the accepted norm ;)

Have you checked with your employer to see if there might be any possible way to make some sort of charging arrangement there where you park? Can you park closer to the building so that a cord could be run to the car? Rather than go to all the trouble and expense of modifying the car, I would investigate to see if you could add a charging station at work somehow, assuming you cannot run a cord to the car - Maybe even going so far as to have a new power pole with a meter installed where you park. You're going to need it for the foreseeable future, aren't you?

Are there any other businesses or houses in the vicinity of the parking lot where you work? If you can't charge at work, then I would canvass the neighborhood to see if I could make arrangements with another business, or maybe park it at a private residence nearby where you could pay them to allow you to recharge while you're working. That $4500 could pay for at work charging for more than ten years - It might even be at no extra cost, considering you're going to have to recharge those LiFePo's at home anyway

Granted, you could make your ideas work, I'll give you that - Given enough money and ingenuity, you can make most anything work, but 'practical?' - I'd have to argue that a bit. I would certainly look for every other simpler solution to your problem before I spent the money trying this one

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

JoeS
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Location: Los Altos Hills, California

Re: solar on the car roof

Tue Jul 24, 2012 9:04 am

PV1 - I'm confused, as perhaps I missed your posting that you've actually bought your iMiE and are driving it. :?:

If you continue doing the math, you need to derate all your components: battery usable capacity, inverter and charger efficiencies, etc. And don't forget to add a very sophisticated and expensive BMS for those Lithiums, not to mention the packaging to keep the cells tightly compressed, and a decent cooling system for the inverter and battery pack. Total weight and locating and moving that weight around is another issue.

In any case, you're talking about converting our relatively light and nimble lovely little car into a top-heavy much less desirable vehicle, all at the possible gain of a few puny miles.

I fully agree agree with Don's comments. Since my Sparrow has a usable range of less than 25 miles (even though I could go 50 mile on a bet), i quickly learned where the power outlets are at the local stores, dentist's offices, schools, med center, etc. They're there, just need to look for them and be civil in either asking permission to use them (always explain the tiny $ consumed and offer to pay), or begging forgiveness... you need to have been in the Jazzercise class when a cop walks in demanding to know who owns that electric vehicle and asserts that electricity is being stolen from the city… while they're unnecessarily burning 12kW in incandescent overhead lighting in a room full of windows, but that's another story.

Off Topic: MLucas, the vehicle is a Corbin Sparrow - my biggest surprise was how stable it is at very high speeds.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

PV1
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Re: solar on the car roof

Tue Jul 24, 2012 9:33 am

No, I don't have an i yet. Actually, discharging the second pack would take 8 hours, enough to give you 7.5 kWh, which at 3.5 mi/kWh, adds 26 miles of range. A round trip to work for me is 80 miles, which pushes the LEAF's range. So, say an i gives you 55 miles range on the highway, I use up 40 miles, leaving 15 miles, plus 26, gives me 41 miles. That's judging all 80 miles are on the highway, but only 60 are on the highway, plus about a mile crawling to get to the highway. So that leaves me with about 6 miles extra.

So it's not "practical" in a sense, but for no way to get a plug, it's not bad. It was asked if it could be done, and I provided an answer.

This setup is meant to take advantage of the sun beating on a parked car that is going to be sitting there for 10 hours, charging or not. This is the easiest way to use solar to charge the car when the infrastructure is unavailable. Another way to go is to hack the CHAdeMO port and charge the battery directly, but that opens up a whole other set of issues.
:idea: :idea: :idea: :!: :!:

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JoeS
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Re: solar on the car roof

Tue Jul 24, 2012 11:15 am

OK, so given the constraint that it's impossible to charge either at work or somewhere closeby :( , would you be allowed to build your own solar-powered charging station carport onsite and leave it there?
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
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Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: solar on the car roof

Tue Jul 24, 2012 11:35 am

That would work . . . . at least until it rains all day one day and he's forced to walk home

I'm trying hard to 'picture' where he works and that there is no possible way to recharge conventionally within a block or two . . . . must be a pretty remote place

We have several 'solar worshippers' here (Joe and myself for two) who would like to do everything solar powered - Joe actually does, recharging at home using solar power. We'd all LOVE to drive 100% solar powered, recharging whenever and wherever we liked using only the sun . . . . and you could actually do that most of the time even at work, utilizing a 'solar carport' as Joe suggested, but you'd still need a plug as backup for not so sunny days. The impracticiality (there's that word again) of doing something meaningful with a solar panel actually mounted on the car would make most of us (no matter how much we love solar power) think twice about doing it

If you actually buy an iMiEV and decide to try any of this, please document your experiments and take plenty of pictures - I'm sure we'll all learn a lot from your efforts

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

jennrod12
Posts: 223
Joined: Sat Feb 11, 2012 8:51 pm
Location: Santa Clara, CA

Re: solar on the car roof

Tue Jul 24, 2012 1:48 pm

Ya know, "a block or two" sounds pretty cool in your head, but you'd be surprised at actual distances involved. I work in Silicon Valley in a fairly dense area. I'm in a 1-mile long strip of individual buildings none of which have ANY outdoor outlets. Across the street is a freeway. I'd literally have to walk at least a mile to find any kind of charging, and since I'm surrounded by like buildings, I think it might be 2-3 miles before I found anything.

My company leases the building from a landlord, as with all the surrounding buildings. My company doesn't have the say in putting in outdoor outlets. There is a company about a mile away that is thinking of putting in charging stations (they own their own site), but I am sure they will be for THEIR employees, and even if they are not, those stations would quickly fill up. And I'd still be adding 15-20 minutes on each side of my commute walking to/from the car.

Just saying that you don't have to be in a remote place to not have access to charging.

Jenn
2012 Diamond White i-MiEV ES
with green racing stripes and hubcaps (thanks to WeeJohn)
Santa Clara, CA

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