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How much would you be willing to pay for the solar panel option?

  • I don't want the solar panel, even if it's free.

    Votes: 54 12.7%
  • For $40k, that panel had better be included in the price.

    Votes: 90 21.2%
  • I want the panel, but won't pay more than $250 for it.

    Votes: 73 17.2%
  • I want the panel, but won't pay more than $500 for it.

    Votes: 109 25.6%
  • I want the panel, but won't pay more than $1k for it.

    Votes: 61 14.4%
  • I want the panel, but won't pay more than $2k for it.

    Votes: 23 5.4%
  • I want the panel, and will pay more than $2k for it.

    Votes: 15 3.5%

Solar Panel Option for Chevy Volt

102K views 159 replies 78 participants last post by  hparker 
#1 · (Edited)
There has been quite a bit of discussion centering on a possible optional solar panel on the roof (?) of the Volt. Without knowing any details on the panel, we can make a reasonable guess that it would be capable of putting out 100-200W under direct, full sun. This is clearly not enough to provide a meaningful charge against a possible 40-mile all-electric range, but it could be enough to provide other services - as yet unknown.

How much would you be willing to pay for the solar panel option? You may select only one choice.
 
#56 ·
It really would be solar powered for the typical user down here in Florida, at most they are going to cruise a couple of miles and then sit all day drinking beer and eating.. but I can see an all day leisure cruise down a canal in New York state and its canal system, that sounds like a really enjoyable experience... no loud outboard din or the awful smell of the exhaust.
 
#61 ·
Thanks for the excellent post, Geronimo - as usual. The Osprey looks really interesting. I was envisioning it converted into a small houseboat. The area available for solar PVs on the roof reaches the point where you could truly have a solar-powered boat.
 
#62 ·
It's fun to look into some things on the threads that catch my interest, but it's nice to see that someone appreciates my comments.

I hadn't been aware of this move to electric boats in the last few years: I don't want to buy one, but I will look for them now on lakes when vacationing. I'd like to see how quiet they are, they probably make good tour or cruise boats :)

And the solar power is a nice attraction: I hope they have a small display showing how much power they have captured that day, or week... something like Google's display:
http://www.google.com/corporate/solarpanels/home
 
#63 ·
Good Info, Geronimo

Well, I just found these GM-VOLT forums, and have been browsing because of the interesting subjects. And I have to agree with Altizi, Geronimo you have posted some good stuff. For example, the peak oil graphs. -- If I could just figure out which stocks to buy before alternate energy takes off like a rocket.
 
#64 ·
Well, I just found these GM-VOLT forums, and have been browsing because of the interesting subjects. And I have to agree with Altizi, Geronimo you have posted some good stuff. For example, the peak oil graphs. -- If I could just figure out which stocks to buy before alternate energy takes off like a rocket.
Thanks mike - and yes, any great transition brings great opportunity.
Good luck with your investing :)
There are lots of websites and email newsletters with investing advice, but nothing is a sure thing: a lot depends on the principals in the company, luck with the timing of technical improvements, and worldwide relevant developments.

First Solar just had a jump in stockprice yesterday as they announced a huge project in China - I just heard about it on gm-volt.
I like SunPower products for retail applications - good, long lasting efficiencies.
Clipper Windpower is a pure play American company, working on a 7.5 MW turbine for offshore applications - I'm not sure how it will fare financially, but I like their 'largest turbine in the world' ambitions. The Queen of England is a customer.

But a lot can happen in just two years - it all depends on financing raised, technical improvements, what competitors come up with, etc. There are some good Chinese companies in the wings, good Danish wind competitors, good German and Japanese solar competitors, etc.

On the fringes are companies working on tidal power, ocean wave power, things like that. Some might make good profits in their growth phases.

I would love to see fusion power perfected, but it seems it will require the resources of many governments to get it right - probably not a good 'profit situation' for a few decades, but a nice advancement for humanity.
 
#66 ·
Since everything is electric on the Volt, it's just a net sum that matters. What ever the output of the panel is, it just goes back to the battery to run whatever. The problem is, the cost to performance ratio of a panel on the roof is likely to be pretty poor. At this point in solar panel technology such a device would be more gimmick with bragging rights than actually very practical.
 
#68 ·
I personally don't care if a Solar Panel feeds into the battery or not.

I like the Prius' solar powered ventilation system idea (although I have no experience with it). But if it can keep my car a few degrees cooler in July in Phoenix, I'm all for it.

It may even be able to divert some power to the battery thermal management system.

I'll definately get the Solar add-on as long as its reasonably priced. The Solar (from what I can tell) adds about 1800 bucks to the cost.
 
#69 ·
I did some calculations a while back and determined that a 1 sq meter panel, at 15% efficiency could provide an additional 2-4 miles of driving range for the average driver. I used this link to create a map for a horizontal, flat panel type array.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/


The average solar insolation value for the US seems to be around 4.5 kWh/m2/day
Two or more sq meters could easily be achieved by covering the roof/hood/deck lid with a thin film solar array that would perfectly fit the contour of the vehicle.

Some math:
2 sq meters of surface area, and a 15% efficiency of the thin-film array = 1.35 kWh/day
Assume the Volt requires an average of 250 kWhr/mile during normal driving: Increased Range = 5.4 miles
Assume 80% charge/discharge/conversion efficiency (losses): Range = 4.32

GM is paying (very) roughly $1000/usable kWhr of battery pack capacity...so I guess if they could install solar for less money there might be a business case for it.

However, there are other benefits:
The weight of a solar array producing 1 kWh/day should be less than 1 kWh of battery capacity
10% of the average daily energy would be "green"...even if you live in an area where coal fired power plants are the norm.
Even greater benefits would be realized by people living in the SW
 
#70 ·
Here is a laminate panel 3/4 of a sq meter.
http://www.sunelec.com/gs-solar-laminate-46-watts-4800-vmp-p-1504.html

It produces max insolation 46watts, but it is impossible to achieve max insolation unless you get a dual axis tracker at some high altitude. Generally a 0.77 derate of name plate watts is accepted practice. Laminates take about double the area of crystaline panels.

This link can help you understand your possible harvest.
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/

I think given the area available and the poor orientation a roof and hood would give it really is a gimick to add laminate solar to a car. You could get some crystalline custom panels made that would produce more but again the orientation would still be poor most of the time. One other thing that affects panel output is temperature. Panels are generally rated at 20C but a car roof is extremely higher mid summer especially in the South. Production falls off dramticly at higher temps. In winter in northern climates snow covers a big issue.

I have 72 175 watt crystalline panels orientated due south on a 5/12 pitch roof that has 6 inches of air space underneath for cooling them and the very best I have seen it produce is about 1kWh per panel per day in early May when the temps are ideal and days are getting longer and the angle of incidence is nearer ideal.

My conclusion is panels on a car are most definitely only a gimmick at any price. You would be better off placing the panels on your house roof where the space and conditions might be better and use the power from that to charge your car and reduce your electric bill.
 
#71 ·
My conclusion is panels on a car are most definitely only a gimmick at any price.
The panel available on the Leaf is arguably not quite a gimmick, in that it ignores the HV battery and is used to trickle charge the auxiliary battery. As a few Volt owners have learned, a Volt with a fully charged HV battery and a dead Aux battery is a completely dead Volt (and a Leaf with a dead Aux battery is just as dead). So it could serve its intended purpose there (though it would probably take awhile to get you going again).

I'm not saying it's a strong argument, but at least it's a case.

The Fisker solar roof can't be anything but pure pseudo-green bling IMHO. But then again, the Karma actually really is mostly pseudo-green bling already, so that's not in any way to detract from the car's charm. If you're going to buy a 400 HP super-sexy sports car anyway, the Karma isn't a bad way to go (TBD on how it actually pans out as a real car).
 
#73 ·
I answered $1K, I was thinking for something more advanced than current technology that could cover the entire uppper surface of the car with panel - anything less would be, in my mind, not workthwile at all, and my logic was this.
Max solar panel output of a panel that covered the entire upper surface of the car might be 1 kW. I figure an innovative technology might be able to put about 4-5 sq. meter of panel on the entire upper surfaces of the car, enough, given reasonable inefficiencies and such, that MAYBE you could get 1 kW peak out of that . Assume you park it in unshaded spot 9-10 hours a day (typical time I am at work) and that it gets a total of 6 kWhr in the time, and that I do this 200 days per year (about the number of days I am at work). That is 1200 kW at 11 cents = $132. I always use a multiplier of 5 for the present work of a continuing future savings stream of $132 a year is only $660. But it would be worth something to have the car charged with an extra 20 or so miles when I got out of work, so, $1000. Such panels, I estimate, would cost well (well) over $10K, so I am not holding my breath.

I have no interest unless the panel could provide meaningful charging for the car. Given that a realistic version on the roof today might add 1.5 kWhr during an all day charge (say 6 miles) it would be marginally useful, but not $1k worth, although I might buy it just for the novelty - $1K is not that much compared to what the car cost.
 
#74 ·
Just to set some expectations, the most efficient panels commercially available are 19%, sun power. At perfect insolation a 1.5 meter sq. Panel is rated at 320 watts. But you can never get the rated insolation, if aligned directly at the sun an correct temps you might get 320 x 0.77 watts = 246 watts. A car roof and hood will never be align correctly so cut that in half at least. These are crystalline cells behind low iron glass hermetically sealed from weather, mounted to a solid low vibration environment.

In theory the sun puts out 1000 watts per sq meter with no atmospheric effects. With a conversion of 19% and add atmospheric effects the physics says you get much less. BTW the 19% is at ideal temp, with perfect incidence perpendicular to the sun. Add pollution, water vapor, tempurature and other atmospherics the conversion is always less. Usually much less. Look at the green line in my TED output and you can see what I mean. Laminate efficiency is more like 7%.

I really do wish the technology could get that level of collection, several people are working hard to get 40% but they are no where near commercialized yet.
 
#75 ·
My thinking was I could get a total of about 5 sq meters at 19% = roughly 1 kW, which for ten hours at 60% efficiency would give the 6 kW. Such output is reasonable if a high upper limit - reasonable for, say, Phoenix on a summer day. I have some cases covered in a book I wrote on distributed power generation in which fixed flat panels that were tested in NM got that output on summer days.

http://www.amazon.com/s/ref=nb_sb_ss_i_0_29?url=search-alias%3Daps&field-keywords=distributed+power+generation+planning+and+evaluation&sprefix=distributed+power+generation+

If it did, it would make a noticeable improvement in utility of the vehicle. I imagine, though, that the panels would look ugly covering the entire car - worse than, say, unfinished carbon fiber body panels you see on edgy show cars, etc.

As long as we are being extreme, I've seen a study that looked at another solar power method. If designed into teh car, it can use the heat of sunlight on the interior to heat the air in the car, routing it through a small wind-turbine to the outside, while drawing air from cooler environs underneath. Maybe 15-35 watts on a hot day - but you cool the interior slightly versus not, and gain, over an eight hour day, another mile of range. (This really does work although much better in larger systems - you can google "solar updraft tower"

Anyway, its fun to think of it but I'll stick the the plug.
 
#76 ·
Go run pvwatts progRam for a 1 Kw array at zero degree tilt, peak month is 167 kWh for the month in Phoenix. But that assumes you get a 1000 watt array on the car. It would need to be crystalline cells under low iron glass hermetically sealed and rugged enough to stand up to the car environment. I contend there is not enough space nor the technology to meet the environmental conditions
 
#77 ·
We don't use pvwatts or trust it at all. Our own software says only a bit better but as I stated, I was assuming some extention of technology based on a couple of improvements we see to 10% better specific output and angular output sensitivity, and 5 sq meter would do it, I think.

This is a ll acedemic - its a non-starter as a viable idea anyway.
 
#78 ·
I think we both agree that is the case! :D

Just as an FYI pvwatts tends to be a bit conservative, my solar system produces slightly better results as well.
 
#80 ·
Solar panel for roof



Given a bright sunny 8 hour day at work, a 200 watt panel would put about 1600 watts back into the battery.

That would be good for about 5 miles at 8 hours of sun. Given gas costs about $3.80 per gal and the Volt gets 40 mpg on gas, that comes to 9.5 cents per mile. That would equate to $0.475 worth of gas per day = 5 x $0.095.

If the panel costs $500, that would come to a 1052 sunny day breakeven. For those of us that park in a garage on weekends, that puts the breakeven out past 3 years.

For the solar panel to be popular, I think most would find a 3 year payback acceptable. In the southern states, the payback would be quicker.

I would pay up to $500 living in the midwest.
 
#81 · (Edited)
Given a bright sunny 8 hour day at work, a 200 watt panel would put about 1600 watts back into the battery.
This assumption is wrong, a 200watt panel will only really output 200 X 0.77 in the real world if pointed directly at the sun and at optimal temperature conditions. Because the angle of incidence would never be optimal being roof mounted the actual output much less. Also the 200 watts is calculated using 1000 watts/m^2. real world is never that. Usually a fixed panel is considered exposed to 4-5 hours of "good" sun per day. The energy looks like a bell curve assuming a cloudless day. The total area under the bell is equivalent to 4-5 hours of full sun.

so 200 X 0.77 X 4 = 616 watts per day on average. for more accurate numbers go here http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/US/code/pvwattsv1.cgi

The attachment is an example of a 1000 watt array in Phoenix, AZ, one of the most sunny places in the USA. Take any of those month kWh numbers and divide by 30 and divide by 5 for a best case 200 watt panel. you can see in May the best case for a day is 1133 watts but in Dec and Jan it is barely 400 watts a day.
 

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#83 · (Edited)
Zoom and screen snap right out of nrel's PVwatts. Me likes MACs for making it easy. 1000 (1Kw) watt array is as small as they go.

BTW those $$ values are for $0.175 per kWh, the Phoenix on peak rates for my TOU.
 
#86 ·
There ARE solar panels that are more energy dense 39%+ efficiency already exists for non-space applications, that means roughly 40 watts per square foot mid-day, not sure how much space is on the volts roofline but I would guess 4'x5' = 800watts peak, 500watts nominal could be fit up there with a bit of effort.
http://boeing.mediaroom.com/index.php?s=43&item=1531

That would be several free miles a day, longer battery life, etc.

But GM should focus on reducing the cars "idle" consumption as much as possible first, with a high tech low power lcd, ecu, etc they should only need about 35-40 watts to run the car, leds on everything light wise.
This 500watts to idle business is rather sad considering my ceramic heater uses that. (to put it into perspective)

But this is the trend on all cars electric and non-electric, electricity use for accessories on gas or EV vehicles does cost money in the way of wearing batteries and Fuel economy (or electric range)

Cheers
Ryan
 
#87 ·
There ARE solar panels that are more energy dense 39%+ efficiency already exists for non-space applications, that means roughly 40 watts per square foot mid-day, not sure how much space is on the volts roofline but I would guess 4'x5' = 800watts peak, 500watts nominal could be fit up there with a bit of effort.
http://boeing.mediaroom.com/index.php?s=43&item=1531

That would be several free miles a day, longer battery life, etc.

But GM should focus on reducing the cars "idle" consumption as much as possible first, with a high tech low power lcd, ecu, etc they should only need about 35-40 watts to run the car, leds on everything light wise.
This 500watts to idle business is rather sad considering my ceramic heater uses that. (to put it into perspective)

But this is the trend on all cars electric and non-electric, electricity use for accessories on gas or EV vehicles does cost money in the way of wearing batteries and Fuel economy (or electric range)

Cheers
Ryan
Any idea on the cost of these cells? I bet they hare hugely expensive still.
 
#90 · (Edited)
San Diego Gas & Electric has a couple of pilot programs that sound interesting.

The first is called "Share the Sun", this is sort of a virtual net metering plan. Essentially you purchase some of the output of a solar plant in SDG&E service area. Then SDG&E gives you credit for the amount of power you purchased so that each KWH purchased offsets a KWH draw off the grid.

The other plan is called "Sun Rate" which allows the rate payer to specify from 50% to 100% of their power usage should come from local commercial solar sources (I don't have a clue how this works at night!). The interesting thing about this is SDG&E says this power will billed at their actual cost.

With either plan you could honestly say the electricty needed to power your Volt comes from the sun, even if you don't have solar panels on your roof.
 
#91 ·
I did some calculations that a solar panel on the roof, tied into the traction battery in some fashion (whether it's directly being used for miles or offloading climate systems) would add maybe 3 miles range to the car. That's GAS saved, not electricity, so about 10¢/mi , or 30¢ per day. It would take 5 years saving 30¢ per day to pay back an investment of $500, so that was my vote.

But realistically, I park indoors at home and work, so I'd except only about 30 minutes to an hour on the road each day, It wouldn't generate much electricity at all for me... so even the estimate above is way over the top.

3 miles per day was based on my Whr/mi rating and some stats I got from an Energy Del Sol solar mat for RVs. It produces 68W from a 13.5 sq ft pad. There's probably better grades of PV cells out there, but it was a start.
 
#98 ·
You have two options: Flex panel, with about 50% output, but you can walk on it. Or normal silicon that is fragile like a butterfly wing.
You'd need curved tempered glass or polycarbonate. The weight is not trivial.

But it doesn't generate a lot of power. The kids built a solar bicycle with 900w of panels. Ineffective.

You are best off putting up the same panels at a ground location, and using it to defray charging costs. That is the best use of money. Mounting on the car adds weight up high. The top of the car is very aero sensitive.
 
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