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EV World Open Access Article |
Florida electric vehicle station uses solar energy. The author contends that even with the high cost of solar cells, it costs less to run vehicles on solar energy than on gasoline.
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Solar PV Is Cheaper Than Gasoline
Charging an electric vehicle with sunlight costs less than running a vehicle on gasoline
By Stephen Killough
Open Access Article Originally Published: May 31, 2005
Are solar cells a waste of money? Not if you compare them to gasoline.
Most people consider solar cells to be impractical. They always make comments like solar cells are too expensive, useless at night, ugly, undependable because of clouds, and would require cutting down trees. For the typical home application, these are unfortunately valid complaints, mainly because solar cells have to compete against cheap coal. However, compared with gasoline, solar cells can be quite competitive.
This example deals with one of the largest users of gasoline, people driving to work. Of course I am talking about battery-electric cars recharged by solar cells, but for a different twist I am proposing that the cells be located not at the owners home, but instead in the parking lot where the owner works. Why at work? Because when the sun shines, that’s where the car is. In addition, expansive employee parking lots are not shaded by trees, and shade from cells mounted above the car keep the car from becoming hot on summer days, and can reduce rust and paint fading caused by rain and sunshine. And nobody will accuse you of harming the appearance of their beautiful asphalt lot. The nine-hour stay in the parking lot is compatible with the recharge time for most batteries, and the lower voltage of the cells is safer than regular electrical outlets, especially in wet outdoor locations. The employer would not have to provide anything except anchor points to keep the panels from blowing over.
Even more interesting are the economics. A typical parking space is 9 by 18 feet, or 2.74 by 5.48 meters, for a total of 15 square meters. A typical latitude in the U.S. is 35 degrees, so tilting the panel to face the sun allows more panel space to be mounted above the same parking space, or 18.3 square meters. Typical solar radiation is 1000 watts per square meter, and using high efficiency solar cells like the 20% efficient A300 units from Sunpower, 200 watts can be obtained per square meter. Without a tracking mechanism to continually point the cells toward the sun, the average power over 9 hours is 60% of the peak power, or 120 watts per square meter. All this adds up to around 20,000 watt-hours for a typical 9 hour work day. This is a significant amount of energy that can be collected from one parking space, although this also points out how much land we waste parking our cars, but that’s a story for another day.
The present day cost for solar cells is about $5 per peak watt, so the 3660 peak watt system described here would cost $18,300. Using a mortgage calculator we can calculate a loan for this system using a 20 year loan and 6% interest rate. This comes out to a cost of $131 per month.
An efficient battery electric car, such as an EV1, consumes 170 watt-hours per mile. The 20,000 watt-hours collected by the solar panel would thus power this car for 118 miles per day. A typical month has 22 working days, during which the solar panel could power the car for about 2600 miles. Compare this to a very efficient gasoline powered car that got 40 miles per gallon, traveling 2600 miles and paying $2 per gallon for gas. The monthly gasoline payments would be $130, essentially the same as the solar powered case.
Some of you may think that it would be better for the environment to connect the solar cells to the electric power grid to displace the use of coal. Per basic heating power, gasoline does generate less carbon dioxide than coal because much of the heat comes from the hydrogen in the gasoline molecules. However, coal generating plants are more efficient than internal combustion engines, so the carbon dioxide emissions are similar whether using gasoline in a car or coal in an electric power plant. Therefore solar cells can displace a similar amount of emissions in either case. But my objective is to promote more solar cells, and the way to do this is to sell them in a market where they are already competitive, which is the gasoline market. Furthermore, in many cases solar power does not displace coal, but displaces more expensive fuels like natural gas, even though natural gas is cleaner. Economic wise, it will always be difficult to displace coal because it is so cheap. After all, the commodity can be simply scraped off the ground from huge coal fields in Wyoming, delivered in railroad cars without even requiring a lid to shield it from the weather, sent to the furnace after very little refining, and usually burned without any treatment of the combustion products.
Another reason why solar cells, and even wind power, can me more useful charging electric cars is that battery charging is forgiving of one of the main problems with renewable energy, which is the reduced available power during cloudy and low wind conditions. The electrical grid requires a specific amount of power to match demand at any given instant, whereas battery charging can use fluctuating power levels as long as the total energy produced for the day is adequate. Even if it is not adequate because of an anticipated weak solar day, the batteries can be partially topped off at the employee’s home from the electrical grid at non-peek hours.
Of course this is all academic if no one sells battery-electric cars. However, plug-in hybrid electric cars may soon become available, and their expected battery-only range of 50 to 100 miles will be a good match to the output of the parking space sized panels. And there is always hope that someone will start making battery electric cars again. If your commute takes you only through neighborhoods with 35 mph speed limits, you can drive a battery electric GEM car today. Hopefully GEM or another battery electric car manufacturer will take the next step and upgrade to a highway capable car soon.
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48 comments so far...
05-Sep-2008
63670
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I would love to see one of these qualified posters re run this calc today. Most economists project gas to stay at least $4/gal for many years. Also, It does not seem either side included the maintenence cost of the gas car, since EV's need very little beside battries.
One would also have to add that there will be no tax credits, CO2 credits, or green power payments for gas cars.
Thanks,
Posted by: Tom Balderston
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26-Apr-2006
19555
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With gas at more than $4.00 a gallon here in Costa Rica and the government just reducing import duties for EVs the interest is growing. We are working on a client's 3kw charging station for a yet to be purchased EV. This article just highlights the good sense it makes to invest in a transportion fuel source like a personal solar charging station.
Posted by: bruce carey
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08-Apr-2006
17466
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California provides 50% of the cost to install solar panels on a home. They are configured with a connection to the power grid. The electric meter runs backward - reducing the use of powere from the grid and your electric bill. Excess poweris sent to the grid. KYOCERA is a source of solar panels. A system can be bought at Home Depot. The also sell a mini system that will power your whole house fan. Why not mount cells on the roof, hood and trunk of the car???
Posted by: allan haller
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10-Feb-2006
12771
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Steven,
Very interesting article about building solar chargers for EV at work. It makes a lot more sense than having one at home.
You mentioned that coal power plants are more efficient than the internal combustion engine, and that we should use solar car chargers to offset vehicle emissions as opposed to sending that power to the grid.
That makes sense if all the cars are using all the power generated by the chargers. Chances are almost nobody would use all the power charged in their car every day. I only commute 8 miles to and from workeach day. All the rest of the potential power from a charging station wold be wasted.
Posted by: ethan holmes
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10-Feb-2006
12772
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. . .I say, send all that power to the grid! It will ALL get used. An influx of solar energy into the grid means less coal burned to meet the same energy demand. Thanks!
Posted by: ethan holmes
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01-Jun-2005
7830
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Hi Stephen,
Great article. I have only one question. Why don't you hook these solar panels to the Grid as well. I can't imagine EVs needing all the power from these panels all the time. Wouldn't there be a surplus with this system every once and a while?
Peter"
Posted by: Peter W
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01-Jun-2005
7831
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Why not more distributed power? If GM put decent cupholders and radios in their EV's they'd sell like hotcakes. Frankly, don't understand GM's thinking. Good article. Thanks! "
Posted by: Jim O
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01-Jun-2005
7832
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Twenty kilowatt hours! A surprise - I had to do
the arithmetic myself to confirm it. Nicely written
article."
Posted by: Jim Tonne
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01-Jun-2005
7833
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Reason for GM to not make EVs is simple, they don't want ordinary people to find out that EVs are cheap
to produce once in mass market, U will not need to buy spare parts where GM makes big margin profits.
EVs are extremely reliable in comparison to ICE. Iron ships were not produced by those who built sail
ships. Who is gonna make money on all those parts that revolve in ICE cars - noone. I for one will never buy GM car only cause those assholes care of their profits not environment. All they do is feed general uneducated public (u don't learn physics at scool) the idea of hydrogen which is BS. Why anyone in hell want to produce H2 from methanol to burn it in cars,lol. why not just let methanol burn there instead? Idiotizm. Its so sad to watch
this. Writing is on the wall - EVs is future, but
politicians turn their faces away getting money from oil lobby. "
Posted by: Alex D
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01-Jun-2005
7834
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I agree that this is would be great and is within the realm of possibility, but the cost of electricity is actually a minor cost and you can't say this is currently anywhere near as cheap as gasoline. The current amortized cost of the vehicle battery is on the order of twice the cost of the electricity it holds."
Posted by: Greg Collins
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01-Jun-2005
7835
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I really enjoy this kind of calculation! PV power is indeed cheaper than gas, right now - fascinating. The only problem is that PV power is still about 4 times the price of plug-in power. From your numbers here: $131 a month "mortgage" cost for 20 kWh per day (for full sun - someone could factor in a reduction for % cloudy days, lower winter yield). Even crediting all 30 days per month thats at most 600 kWh per month in perfect weather, that's $0.22/kWh. You'd need net metering to be able to feed the power to utility when nobody is at work on Sat/Sun/holidays. If we only count the 22 days we park at work, the 440 kWh sent to the car would effectively cost nearly $0.30/kWh. Factor in cloudy days and the effective price goes even higher.
If the alternative is grid power, this is a less attractive deal than paying perhaps a few hundred per space for GFI outlets throughout the lot (plus a few hundred more for fabric sunshades, to be fair?) and they paying utility rates for a quarter of the cost of this solar power.
Still, nice illustration of the "pros" of such a scheme."
Posted by: Jim Prall
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01-Jun-2005
7838
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Or you could just buy two EV cars and have a solar shelter at home. Then just rotate daily.
What employer is going to go through the trouble? Unless they can make a buck off of selling you the power."
Posted by: John Adams
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01-Jun-2005
7840
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Let me see: $15,000 for the add-in battery pack, $22,000 that the dealers get for the Prius. That adds up to a $37,000 car. Even if you can put 20% down, with a 4.24% interest rate that's $673.34/month over four years. This doesn't sound like a solution for ordinary mortals."
Posted by: Bob Wakefield
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01-Jun-2005
7843
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The PV's on the roof at work can be used to send electricity back to the grid on weekends and holidays thereby spinning the meter backwards which will decrease the electric bills for the the business."
Posted by: Mike McSorley
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01-Jun-2005
7845
| |
Good article. I didn't know that panels with a 20% efficiency were available for sale."
Posted by: Sledge _
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01-Jun-2005
7846
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PV and PHEV cars and gasoline from municipal sewage and landfill waste and meat packing waste could make petroleum based fuel obsolete. See www.changingworldtech.com for details on the fuel."
Posted by: Mark Wiener
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02-Jun-2005
7859
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One correction to the math. Assuming that you use adjacent parking spaces, solar panels tilted 35 degrees have less area available than flat (if you don't want to shade the panel on the next parking space). The available area is about 15 times .9 (cosine of 35 degrees) or 13.5 square meters. Still, I like the idea. As gasoline heads to 3 to 6 dollars per gallon in the next ten years, and solar panels and batteries get cheaper, it will become a positively cheap alternative."
Posted by: Mark Clay
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02-Jun-2005
7860
| |
Afetr reading the article, and then the comments, I am unconvinced of the scheme, at current levels of technology. As an entrepreneur, I do have faith that improvements in technology can bring the system to profitability, if it is possible. (e.g. enough sunlight) The article does not mention factors of chemical pollution from battery manufacture and disposal, as well as raw material shortage issues. I am not being negative, I am just saying the inventor should take these factors into account.
There are several problems in these alternative energy discussions. First is the promotion of blind ideology, like the ecology crusade, rather than facts. The other is the flush of the armchair inventor convinced of this latest fix-it solution to the energy shortage.
I saw an article in the NY Times recently that concluded that PV is not economical because it would take take (vague memory here!) around 5 square miles to generate all the electricity for the U.S., and the cost of this PV farm would be somewhere near a trillion dollars. What? Only 5 square miles? Thats not a big area! And the trillion dollars? Thats like saying in 1970 that personal computers will never make it since computers are ten million dollars, and supplying them to every one would indebt the economy for years!
Enlough said!
JB"
Posted by: John Brookes
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02-Jun-2005
7861
| |
To all,
We were installing PV for EV charging stations in the mid ninties. The Cookie cutter version was a grid connected 4.5kW car port for six vehicles. We spun the heck out of the meters (backwards) and banked the energy on the grid, to be used later for charging the vehicles. Now we have the utility industry stumbling over themselvs for distributed generation to meet the daily load demand. According to our calculations, just 50% of NEW construction with solar integrated roofing will keep the U.S. energy secure for decades to come.
BTW, the car ports shown in the article look like cra.. compared to BIPV (building integrated PV) from UNI-SOLAR
Doug C."
Posted by: Doug Canfield
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02-Jun-2005
7862
| |
With all due respect, Bob, I think you miss the point. To me, the author is touting the direct use of PV generated energy, not suggesting it be stored up in battery packs for whenever. Also, the Prius is not an EV, it is a hybrid. There is no place on a Prius to plug it in. Finally, if you are factoring in electric vehicle purchase price you need to do so for the gasoline equation as well. Granted, the vast majority of us now drive internal combustion vehicles, but if you make this comparison when replacement time comes........."
Posted by: Ken Grimm
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02-Jun-2005
7866
| |
Sledge -- Only 20% efficiency? According to a paper published in a May issue of the American Chemical Society's Nano Letters journal, a NREL team has shown that solar cells based on quantum dots theoretically could convert more than 65 percent of the sun's energy into electricity.
Refer to the May 24, 2005 article at http://www.renewableenergyaccess.com/rea/news/story?id=30843 "
Posted by: Arnold Larsen
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02-Jun-2005
7868
| |
Stephen has a great idea here!
And there is no reason why solar cells have to be limited to 20%, or be very expensive in huge quantities. The battery pack need not be hugely expensive either -- $15K seems much too high for production quantities.
But you really need to look again at the math! When you jump from 20 kwh output of solar cells to the 170 kwh/mile of an EV, you forgot to include the losses in charging the batteries! The chemical process involved is often less than 50% efficient. So the 118 mile range drops to less than 59 miles if you factor in 50% battery charging losses.
Not to mention that in the real world, the sun clouds over a bit, dust and leaves fall onto the panels, and the batteries eventually age. It is still a wonderful imaginative idea that deserves to be pursued, as the efficiencies Will improve, and gas will eternally increase."
Posted by: f bealle
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02-Jun-2005
7869
| |
Jim -- Cloudy days were already factored in. The 30cents per kwh is reasonable. If you add inverters, the price goes up. If you use a 30 year life expectancy instead of 20 year, the price goes down. If you take into account volatile gas prices, solar looks better."
Posted by: Chuck Simmons
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02-Jun-2005
7875
| |
I meant commercially available. Ya know, stuff you can buy now :P"
Posted by: Sledge _
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02-Jun-2005
7876
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The calculation assumes $2.00 per gallon for gas.
The actual gas cost is much higher when you add
in the military expenditures on the war in Iraq
and the possible costs of air polution emitted
by ICE cars.
"
Posted by: John Boyd
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02-Jun-2005
7878
| |
Now, would someone please step forward and finance an electric car factory? Or, convince Mitsubish to sell their EVs here in a year or two when available. Then this fairy tale can become a true story. And, we need expanded PV production too."
Posted by: Ernie Rogers
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03-Jun-2005
7890
| |
Great article Mr. Stephen! I had no idea that solar-powered vehicles would be comparable price-wise to gasoline-powered ones! Hopefully, more people will become educated about this and put more solar-powered vehicles on the market."
Posted by: Claire Harris
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03-Jun-2005
7892
| |
The picture that you used does not refer to a California facility but one at the University of South Florida in Tampa that I helped build over a decade ago. Check out the website:
http://cerc.eng.usf.edu/"
Posted by: Ray Yettaw
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03-Jun-2005
7895
| |
Ken:
I'm afraid I keyed on the second-to-last paragraph. He's right; there are no battery-electric cars right now. The closest thing would be a Prius with a battery pack upgrade from eDrive Systems. If I remember correctly, the price of the upgrade was estimated to be in the $15K to $20K range. A mass produced battery-electric might bring down the price of the battery pack.
"
Posted by: Bob Wakefield
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03-Jun-2005
7896
| |
Great article. I am sitting here looking out of my window at Fashion Island in Newport Beach. I can see literally acres of cars baking in the hot Southern California Sun. I have also seen this at Palm Desert's Town Center Mall when the temperature has been 113F. I have often thought how great it would be to sit in the shade of a PV array instead of under the direct glare of the sun. Now all we need to do is get some EVs back into production and bring down the price of solar cells (and up the efficiency) then we can get away from our addiction to oil."
Posted by: Noel Adams
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03-Jun-2005
7901
| |
Hey Ernie, I just read in the paper that environmental activist have spent over $200 million in the last decade protesting what Detroit is not doing. With just half of that, I could have well built, 200+ miles per charge vehicles in mass production in a year. Heck, take the other half and we can have the energy to power them from solar.
You want to ask again about the MONEY to build an EV. Maybe someone else is listening."
Posted by: Doug Canfield
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03-Jun-2005
7902
| |
I agree that solar is cheaper than gasoline.
The article doesn't mention amortised battery
cost which typically dwarfs the electricity cost.
For example the Th!nk City EV that we used to
drive would have cost about $.10 / mile for
batteries (based on a $6,000 pack of NiCds, in
retail quantity of *one* pack, giving 60,000 miles) and it cost us around 1.5 cents per mile
for electricity. Still comparable with gas cost
even at volume=1 for batteries!
The article also doesn't mention Time of Use
metering, which, certainly here in California,
means that there is no incentive to match your
PV generation to your energy consumption because you
end up giving your utility hundreds of $ worth of
electricity at the end of the year. Instead the
incentive is to zero your bill which typically
requires much less PV capacity. For example,
one 185W panel might generate, say ~$60 worth of
energy in a year
.185 x .8 x 5 x 365 = 270kWh,
270 x $0.22 = $59.40 (and $.22 is pessimistic)
but that's worth ~1100kWh into an EV charging
after midnight on Time of Use. That'll take the
EV between 4 and 6,000 miles. From *one panel*.
Nick"
Posted by: Nick Carter
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04-Jun-2005
7914
| |
Ray... thanks for the correction. The site I 'appropriated it from' was in Iran and it too mistakenly labeled it as being in California. Is the facility still being used in Florida?"
Posted by: Bill Moore
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04-Jun-2005
7915
| |
Noel... they've come close to your wish in Palm Springs. They just dedicated a huge solar array that I saw from the air back in May as we were landing. Wasn't able to learn much about it, but putting them in a shopping mall instead of in under the glide path of PSP and charging a few bucks to keep your car cool would seem an appealing option, especially in the Southwest. The parking fee could help pay for the support infrastructure for the arrays."
Posted by: Bill Moore
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04-Jun-2005
7923
| |
Let's say a plugged-in hybrid utilizes a 10 kwh NiMh battery at a cost of $5000 a pack. At 170 wh/mile of efficiency, the car can travel ~60 miles for a full charge, and that the battery can be charged ~500 times before needing replacement, so a pack will last for about 60 x 500 = 30,000 miles, with a battery amortization cost of about 16 cents per road mile. Adding to this cost the cost of 30 cents per Kw/h of PV electricity, and one will get: 30 cents/kwh x .17 kwh/mi = 5 cents/mile, plus the 16 cents battery cost, we will get 21 cents of total energy cost per mile. Compare this to a gasoline car at 35 mpg and $2.50 per gallon, for 7 cents / mile energy cost. So, you can see that even getting "free" sunlight energy will cost ya three times the energy cost of using a conventional gasoline powered car. Don't even try to compare this to the Prius hybrid, because your solar energy car will have an energy cost over five times per miles in comparison to the Prius II.
Now we really know why EV are being crushed up and auto manufacturers are selling hybrids. Plug-in hybrids will have to wait for the cost of battery to go way down before they will become economically feasible."
Posted by: Roger Pham
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05-Jun-2005
7926
| |
Solar PV Costs 3x higher than Gasoline. Sorry, I just forgot to put a catchy title to my previous posting. Please refer to my previous posting for a rough calculation as to why this is the case. However, this is no cause for discouragement. Remember that most consumer goods will eventually cost one tenth as much after full mass market penetration as compared to when it was first introduced, for example, the automobiles 100 years ago, the VCR 25 years ago, the DVD player 8 years ago, the PC computer and now the flat panel monitors and TV etc... It just points to where most needed research should be done right now!"
Posted by: Roger Pham
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05-Jun-2005
7928
| |
Roger.. Your estimate of the lifecycle costs of NiMH are way too low. The Panasonic NiMH batteries in the RAV4 EV are demonstrating lifecycles of well over 100,000 miles and SCE engineers projected they could go as high as 130,000 miles before showing any appreciable degradation.
Also, you wouldn't expect the batteries to be as deeply discharged as in a hybrid, even a plug-in hybrid, as you would a full EV.
In addition, once those batteries have reached the end of their useful life in an automotive application -- meaning they won't sustain more than 80 percent SOC -- they have a second life awaiting them in stationary power applications from UPS in telecom to load shifting in regions with high peak power costs. So, there is some residual economic value to even these 'used' packs,which would also skew your numbers.
"
Posted by: Bill Moore
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05-Jun-2005
7929
| |
As Bill says, Roger, your lifecycle figure for
NiMH is way too low and, as Bill also points out,
the application is less demanding than a BEV.
Also your solar costs are high.
A 185W panel might generate over 6,750kWh during
its *warranty* period (25 years) at a cost of
$1480 installed (@ $8/W including balance of
system). That's 22 cents. Add in the CA rebate
and that is 14 cents... take into account that
the lifetime of the panel should be way longer
than 25 years and, well you get the picture...
Also, as I said in my previous post, PVEV'ers
in CA are selling their PV at peak for over 30
cents and then buying back off-peak power after
midnight for around 5 cents. That gives 1.5-2
cents per mile for electricity, whilst your PV
generation is much more valuable because it's
generated at times of high demand."
Posted by: Nick Carter
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05-Jun-2005
7931
| |
My data on NiMh batt. came straight from Panasonic. Search on www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_NimH_Overview.pdf , and you will find that the battery's rated durability is the equivalence of 500 charged-discharged cycles, under ideal condition. Toyota's proprietary information on their NimH battery is not much different, since their battery is made by Matsushita Electric, the parent company of Panasonic. Of course, if the battery is only discharged 50% per cycle typically during use (and deeply cycled once in a while), one may charge it 1000 times, (or up to 1500 times per Toyota's proprietary information if the discharge depth is even less than 50%) but the total mileage per battery will in the ball park of 30,000 miles. The REV-4 has a much larger battery, hence ~115-mile range per charge, so one would expect that it can go much further before needing to replace the battery pack, but its battery pack is also a lot more expensive (>$15,000 ?) such that the cost of battery change is much higher than the remaining value of the car. Overall, the total energy cost per mile would not be a whole lot better unless battery can be made a lot less expensive or a lot more durable than it is now. Ah, yes, if one purchase electricity directly from the grid for about 10 cents per kwh, instead of using PV panels, then the energy cost per mile will still be ~18 cent/mile, still a lot higher than an equivalent gasoline economy car at 7 cents / mile. "
Posted by: Roger Pham
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05-Jun-2005
7932
| |
Sigh. I'm not sure what to think about a note like this. I appreciate the sentiment, but it ignores some currently cold realities. Others have already discussed the battery costs. Both EPRI and Calcars.org cite energy use rating more like 270 whrs/mile. That's what calcars has measured with their prius+ (not exactly a huge car...) You also need to account for an 82% charger efficiency, which EPRI does.
And one should state this again and again: the is no automaker conspiracy about electric cars. The batteries are or were just too darn expensive to provide a car with broad enough consumer appeal.
I think there is probably a future for a plug-in hybrid with 20 mile all-electric range. If the automakers are smart, perhaps they could stack batteries packs as an option for the very rare folks who could make use of something with 40 or 60 miles.
Gasoline should also have a $1.00 or more per gallon Iraq war tax, but everyone on this site probably already knows that...."
Posted by: Jim Beyer
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06-Jun-2005
7946
| |
Bill...Yes it still is in operation. "
Posted by: Ray Yettaw
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06-Jun-2005
7953
| |
What about hail insurance for this thing? I wouldn't like to see the premiums in Texas! Otherwise it's terrific."
Posted by: Matt O'Toole
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07-Jun-2005
7960
| |
Two points. First, live within your income- use a lighter, smaller car and a smaller battery pack. Second, PbA present tech batteries can give 6 Watt hours per dollar installed, every time they are discharged for five years. A 6 kW pack costs $1000 replacement cost, or $200 for 15,000 miles a year. Battery replacement cost then is 1.33 cents per mile. Assume 6 kW hours per 60 mile trip costs $.15*6=$.90, or 1.5 cents per mile fuel cost. We are now at 2.83 cents per mile, half the cost of fueling a gasoline car. I don't care where you get your electricity. I am willing to invest in rooftop solar and batteries. You can use the grid and coal if you want. I think the combination of carport solar, battery ev's and plug in hybrids is a winning strategy. But we need market forces to generate the will to change. How about if you were paid $12 a week to plug your car in? That's the 3 cents a mile savings over the 400 miles per tankfull you now use. The $12 per week will pay for my solar cells eventually. After 10 years and $6000 of savings my solar carport will be paid for and my next 10 years of driving are free. Unfortunately, I rent, and do not have a carport; also, I am 69 years old. I guess I'll be satisfied with my 41 mpg Honda Civic Hybrid for now."
Posted by: richard easton
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07-Jun-2005
7961
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I live in California, we don't have that kind of hail here. Put a sheet of polycarbonate over it. It still works, even if it's less efficient."
Posted by: richard easton
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08-Jun-2005
7987
| |
Here's a different twist on the whole subject.
France is making some interesting compressed
air cars. The PV panels could be used to keep
the compressed air car charged with compressed
air. I do not know how you would even begin
to do the energy conversion math on this but
it seems theoretically feasible."
Posted by: John Boyd
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09-Jun-2005
7998
| |
Why not screen-print PV cells on the roof and bonnet? "
Posted by: David Graham
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15-Jun-2005
8057
| |
I would *love* for this to work. Right now it doesn't. The problem is cost of charger setup *plus* battery pack. If the money spent on policy advocacy were spent on PV and battery R&D we wouldn't need incentives and subsidies. Homeowners would shingle their roofs with PV. "
Posted by: Bob Wakefield
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17-Mar-2008
60813
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we must change to efficient energy or the shit will hit the fan
Posted by: ken dawg
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