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Solar-Power-Augmented Prius Takes the Grid Out of “Plug-in”
15 August 2005
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| Lapp’s PV Prius |
A Canadian engineer has prototyped a Photovoltaic Prius—a 2001 Prius augmented with roof-top solar panels and an additional battery system to supplement the charge in the original equipment NiMH batteries.
Steve Lapp’s PV Prius is still a rough prototype—a demonstration of concept—but even with the limitations of the systems, he has achieved an initial 10% fuel efficiency improvement from 4.5 l/100km (52 mpg US) to 4.0 l/100km (59 mpg US).
From the original description of the plan:
...the fact that [current Toyota hybrids] can run on electricity alone, with their gasoline engines off, offers the opportunity to provide them with more electricity and therefore drive further with the gasoline engine off.
Electricity can be provided from the electrical grid by charging an onboard battery, and depending on where that electricity comes from, it will have various emissions associated with it. [The plug-in concept.] However if it is provided from renewable energy sources, such as photovoltaic panels, then it is “green”.
This begs the question of why not put the PV panels directly on a hybrid car and generate electricity onboard while the car is parked outside, or even while driving. The general reaction of people to this idea is that there could not be enough energy striking the roof of a car to provide enough electricity to drive any meaningful distance.
This is where the incredible efficiency of the hybrid car must be taken into account. To drive a hybrid car about 1 km, takes about the same electricity as to light a 150 watt bulb for one hour! The point is not to drive the car using only solar power, but to effectively use solar power to improve gasoline fuel efficiency.
How much gasoline can this photovoltaic hybrid car save? Well let’s look at the energy available from the sun on the roof of the car. For June and July in Kingston Ontario, about 6 kWh of energy from the sun strikes each square meter of horizontal surface. If we install 2 square meters of photovoltaic panels on the car and we collect 10% of the energy from the sun as electricity (well within present PV efficiency), we can theoretically go about 8 km each day on just the sun’s energy. If we drive 24 km on a sunny day, that is enough to reduce our gasoline consumption by 33%. This would take the Prius from 5.0 l/100km to 3.3 l/100km.
The PV Prius uses a 12-volt PV source with a small lead acid battery and battery voltage controller, inverted to 120 VAC, transformed to 345 VAC, then rectified with current control to nominal 300 VDC. The charge from the PV batteries flows into the Prius hybrid battery when the ignition is on.
The 300 VDC output of the solar subsystem is attached to the switched side of the original Prius battery, so the PV battery cannot recharge the NiMH while the ignition is off. The PV system can inject a maximum of up to 2 amps continuously into the battery while the ignition is on.
Lapp’s modelling predicts a 10%–20% fuel efficiency improvement for the 270 watts of PV (to be bumped up to 360 watts with the additional of a fourth panel), so the 10% on the first trip with little optimization was “a pleasant surprise”.
He is working with between two to six 20 Ah sealed lead acid batteries, experimenting to discover useful amount of buffer storage, given typical solar and driving conditions.
The decision not to charge the hybrid when the car is off was a pragmatic choice, given the financial and time constraints of his project. Among other issues, there would need to be a thorough analysis to determined the optimal PV-NiMH energy flow/charge relationship.
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August 15, 2005 in Canada, D-I-Y, Plug-ins, Solar | Permalink | Comments (61) | TrackBack (4)
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Listed below are links to weblogs that reference Solar-Power-Augmented Prius Takes the Grid Out of “Plug-in” :
» Solar Prius from WorldChanging: Another World Is Here
This one is spreading around the "sustainable blogosphere" faster than Avian Flu -- Green Car Congress has a report on the efforts of a Canadian... [Read More]
Tracked on Aug 17, 2005 11:15:41 AM
» Solar Prius from REverberations
Our country needs cars like this. Liz and I are considering a hybrid when we return from overseas and have saved a bit more.
But with the huge amount of un-tapped solar power our country lets go every second, what a great idea this is.
With new technol [Read More]
Tracked on Aug 17, 2005 3:53:11 PM
» Solar powered Prius from Seven Generational Ruminations
A couple days ago I reported on the plug-in hybrid concept. The idea is to add an additional battery pack for more electricity storage, and configure it to be independantly chargeable. Additionally you configure the controller circuitry to enable an ele [Read More]
Tracked on Aug 17, 2005 4:49:35 PM
» Solar-Powered Toyota Prius Project from ProRinnovabili
Green Car Congress writes about a very cool project by Canadian engineer Steve Lapp who modified his 2001 Prius by installing solar panels on the roof. It is admitted that the car is still a rough prototype, but so far the fuel economy improvement are ... [Read More]
Tracked on Aug 25, 2005 11:35:30 PM
Comments
How heavy are photovoltaics? It just seems like it'd be inefficient to lug them around, both due to their mass and their less-aerodynamic shape.
In general, it seems like it'd be more efficient to keep the PV where the car is to be parked during the day, plugged in.
Still, any improvement is good, so this is good. And, it'd be particularly handy for vehicles that don't park during the day, such as delivery vehicles (which have huge flat roofs), taxis, and big rig trailers.
Posted by: stomv | Aug 15, 2005 6:43:32 PM
bravo, keep up the good work!
Posted by: paul | Aug 15, 2005 7:19:08 PM
The thin film panels dont weigh much at all and they are areo enough being flat and thin. In the end if you realy went all out you would glue the think film right to your roof thus elimainating any wind resistance issues.
And it does protect you from running out of gas;/
Posted by: wintermane | Aug 15, 2005 8:21:17 PM
Ideally, the PVs would be integrated into the roof...but that was beyond the resources/finances of the project. :-)
Posted by: Mike | Aug 15, 2005 10:50:20 PM
A few months ago I was reading somewhere about PV research, and one possible advancement the article mentioned was something like PV spray paint. You'd lay a wire grid down over the surface to be treated, then spray this nanomaterial over it and after it dried (and crystallized), presto, you have a PV panel. I'm sure that technology still has a long way to go but you could imagine the applications, like here, turning the entire surface of a car into a PV panel, with probably no weight or aerodynamic losses.
Posted by: Shirley E | Aug 16, 2005 5:30:55 AM
So, here's my (obvious) idea:
Hybrid postal and package delivery vehicles (UPS trucks, etc). They spend tons of time idling and hybrids turn the engine off. They spend tons of time accelerating and decellerating at low speeds, and hybrids are more efficient in those situations.
And -- they have huge flat roofs, maybe 16 m^2. Perfect for solar cells. Aerodynamics aren't affected if the cells are perfectly flat, and they'd gather energy all day long for the most part.
It would seem like the UPS trucks might be able to double their mpg in those conditions -- why isn't this happening? It seems like a slam dunk!
Posted by: stomv | Aug 16, 2005 5:40:17 AM
I believe that UPS is already experimenting with a hydraulic regenerative braking system on their delivery vehicles. I don't think the cost/benefit/useful life of photovoltatics is impressive enough to interest their beancounters yet. Besides, UPS's big flat roofs are already being put to some use - they are largely translucent, allowing natural lighting to the cargo area.
Posted by: Jason | Aug 16, 2005 9:17:41 AM
should look at SperalSolar, whose new system will permit building & vehicle integrated solar.
http://www.SperalSolar.com
Posted by: Kathy, UK | Aug 16, 2005 11:48:12 AM
^ you prolly mean
http://www.spheralsolar.com
Posted by: stomv | Aug 16, 2005 3:28:51 PM
Not to rain on anyone's parade here, but consumer grade PV is tops 15% efficient at turning the 1 KW/m^2 solar irradiance (at solar high noon) into power. The prius has mebbe a couple square meters, so thats 200-300 watts tops at peak production. Take 10-20% of that power to store it in a battery. That's miniscule output compared to the electric engine requirements on the order of tens of kilowatts of power. It all helps, but at $4-$5/watt installed for PV, the payback is a Silly Long Time. Also, you're dragging around heavy panel, prolly negating any advantage you'd get in non-steady-state driving.
Posted by: marshall | Aug 16, 2005 3:46:45 PM
This is what I've been waiting for!!!! To me - generating and/or capturing energy close to where it will be used just makes sense. I can't be the only one who has walked under power lines listening to them "hiss" and wondered how much electricity gets lost in "transport" along those lines. When you think of all the cars that sit in the sun while the driver is at work, it begs the question, if they had PV car bodies, could they drive home on solar alone? I wouldn't be surprised if we see PV car bodies before we see Hydrogen cars become mainstream.
Posted by: Suzanne | Aug 16, 2005 5:34:03 PM
Marshall is right. It's a small drop in the bucket.
On the plus side, as Marshall noted, every little bit helps. It also has a Gee Whiz factor; it breaks the ice on solar cell applications among people who have never seen them before; it certainly has geek appeal; but I doubt that the energy required to make the solar array and controller will be recovered in motive power at the wheels.
Posted by: Lamar Johnson | Aug 16, 2005 6:21:50 PM
Even if current thin-film panels aren't worth hauling around for most drivers (and the less you drive, the better they'll be), this is likely to change. Plastic PV cells appear likely to be enhanced with the multiple exciton quantum-dot collectors. These cells will be inherently able to be molded to any surface shape. If you combine this with 30% or greater efficiency and possibly a memory capability of rolling over front and rear windows to collect light falling on them while parked (rolling back up for travel), the possible fuel savings will be much greater.
At 175 inches long and 68 inches wide, a Prius has 7.85 square meters of area. If each square meter receives 6 kWh/day and it's captured at 30% efficiency, that's 14 kWh/day; if the car uses 250 Wh/mile, that's sufficient energy to cover 56 miles a day on every sunny day.
The solar-powered commute is a very real possibility. We'll probably see someone doing it within the next five years, and commercial sales a few years after that.
Posted by: Engineer-Poet | Aug 16, 2005 8:40:27 PM
Everyone thinks solar is so expensive, but solar PV is now becoming cost-competive with gasoline. Do the math. A gallon of gasoline has a raw energy content of 114,000 BTU's. This is equivalent to 33.4 kWh (114,000/3413 btu/kWh). But a car engine is only able to convert 20 to 25% of this energy to useful work, so there is only 6.7 to 8.4 kWh of useful energy in a gallon of gasoline. At $2.50/gallon, gasoline energy costs the equivalent of $0.37 to $0.29/kWh. This is about what grid-connected solar goes for and solar is only going to get cheaper.
Steve Lapp has shown us that someday soon we'll see plug-in hybrid cars with integrated solar that assist the car while it is driving; recharge the batteries while it is parked, and put power back on the grid when the batteries are charged. While PV may not provide all the car's energy, it will help us eek out more miles per gallon.
Posted by: Jim White | Aug 16, 2005 10:07:12 PM
According to my calculations, using Kingston, ON, as the location - given its insolation values throughout the year, and assuming 15,000 miles per year driven, driven an equal distance on each day, one would save about 12 gallons (about $30 worth) of gasoline with the 2 square meter, 10% efficient numbers Mr. Lapp provided. That's about a 4% efficiency improvement.
For comparison, improving a 20 MPG vehicle by 1 MPG will save 36 gallons of gasoline over the same distance - 3 times as much.
Even if one achieved 30% efficiency and had 7.85 square meters of PV surface, it would save 143 gallons over 15,000 miles - which is about 12 times as much as the project Mr. Lapp is describing. For comparison, upping a 15 MPG vehicle to 18 MPG will save 167 gallons.
Hybrids currently sold generally increase MPG ratings by about 50%, so say one hybridized a 15 MPG vehicle, it would probably get around 22.5 MPG -- saving 333 gallons per year.
These "solar Prius" experiments are interesting, but one could have far greater effect with much simpler solutions. For example, tires which are underinflated by 20 percent reduce fuel economy by 10 percent. Surveys have shown that about 30% of people have tires that are at least that underinflated.
So, if you think about a national fleet in the US of 180 million vehicles getting about 20 MPG on average, properly inflating tires would up average MPG by .62 MPG, saving the average vehicle 18 gallons per year.
Posted by: Joseph Willemssen | Aug 17, 2005 2:35:33 AM
Jim White, I think it's easier to go from the cost per mile of gasoline to see how much electricity would need to cost per kWh at the same efficiency.
At 55 MPG and $2.50/gallon, it costs 5 cents per mile for gasoline.
Given 0.262 kWh/mile efficiency of a Prius in all-electric mode, it means that any electricity that costs less than 17 cents per kWh is more cost-effective than gasoline at current prices. Pretty much any grid power in the US is cheaper than that.
A 123 watt Sharp panel (which is about 1 m^2 in size) costs about $600 from Real Goods. Assume 30 year useful life and average insolation values for Kingston, ON, and it can produce electricity at 13.2 cents per kWh over those 30 years.
The problem with the economics at this point is more about battery costs than anything. Makers of the Tango EV estimate that their 25 lead acid battery array costs between 7 and 15 cents per mile. Someone familiar with the plug-in Prius project could probably explain what that translates into costs for the extra battery array in a plug-in hybrid.
Posted by: Joseph Willemssen | Aug 17, 2005 2:56:13 AM
Mr. Willemssen, your comparisons would be more apt if you used the same vehicle, pre- and post-solar, for both. Comparing a solarized Prius to a Durango is just nonsense.
Posted by: Engineer-Poet | Aug 17, 2005 4:47:46 AM
"Comparing a solarized Prius to a Durango is just nonsense."
I'm not. I'm comparing gross fuel savings.
Solarized 1st gen Prius - saves 12 gallons every 15,000 miles. If the goal is reducing fuel consumption, then there are much better ways to save 12 gallons of gasoline.
Posted by: Joseph Willemssen | Aug 17, 2005 6:15:39 AM
I think a solar application would make tons more sense if you install PV's on the roof of your garage, and use them to help recharge your hybrid's batteries while it's parked inside.
That way, your garage bears the weight, not your vehicle.
Posted by: steve | Aug 17, 2005 8:08:25 AM
Solar on the roof makes more sense right now.
But 10 years from now I can see you having both. Solar on the roof and PV paint on your car.
Why not have both. Personally I would like to see the Plug-in Prius concept be brought to market. I know Energy CS is doing it. But I would like to see some of the big dogs like Toyota and Ford get in on it.
Posted by: paul | Aug 17, 2005 8:29:01 AM
An article which may be of interest to all is "Experimental Hybrid Cars Get Up TO 250 Mpg" at news.yahoo.com/s/ap/hybrid_tinkerers, which I came across on 8/14/2005. Another article of interest is "Brazil buys into flex-fuel cars" at MSNBC.com on 9/14/2004. The last article is "Muscle, Economy: Have It Both Ways With Ward's 10 Best Engines which I found at wardsauto.com/ar/auto_muscle_economy_ways on 7-4-2005.
Posted by: solar | Aug 17, 2005 8:40:49 AM
I've been fascinated with the idea of adding some sort of pv component to my new gen Prius for a while. I live in SoCal, so we get a lot more sun than Ontario.
The ability to undock the PV would be idea, so that I'd be able to use it for my around town commuting where I'd be using the electric only mode as much as possible (I'd do that hack where you can go to electric only with the push of a button). But if I were doing a lot of freeway driving, say a 100 + mile trip, I'd want to stow it in the trunk to improve my aerodynamics.
I'm very interested in plug in hybrids as a whole, but I don't want to get my electricity from the grid, I'd prefer something sustainable like a solar panel. I'm glad to see that regular folks are working on the issues as proof-of-concept and that perhaps Toyota/Honda will take it as a cue to add these as options in the future. (The new Toyota concept vehicle does incorporate some interesting new developments such as this.)
Posted by: cybele | Aug 17, 2005 10:05:29 AM
Cybele,
"I'm very interested in plug in hybrids as a whole, but I don't want to get my electricity from the grid, I'd prefer something sustainable like a solar panel."
Solar panels or a micro-wind turbine would be ideal, but have you considered buying your electricity from a green provider? I'm sure there are many to choose from in California.
Posted by: Mikhail Capone | Aug 17, 2005 10:24:52 AM
good point on buying green electricity.
Posted by: paul | Aug 18, 2005 9:10:38 PM
It's great to see the idea and potenial. It's not about the cost savings it's the idea and potenila.
MY solar is on my home and grid ties at the beat angle and area available in sunny AZ, I also drive a hybrid but mostly my bicycle to be real efficient.
On a vehicle it would be at the wrong angle, partly shaded and non aero dynamic . But it poves the point just like a solar racer in the solar challenge.
The point is solar is great, efficient vehicles are great but don't have to be tied together all the time to be used and learn from them.
Jim
Posted by: Jim Solar Stack | Aug 19, 2005 7:52:16 PM
The performance of the Canadian prototype speaks for itself. Maximum Pb battery capacity of 120ah @ 12VDC would weigh ~80 lbs. The same capacity in Li-Mn would weigh ~40 lbs. 700Wp of conventional, glass face, aluminum frame PV would fit on the car and weigh ~ 160 lbs. Aerodynamics and weight would be inconsequential at typical US/Canada speeds. Plug in Hybrids with grid interactive inverters might be more practical with widespread PV. The most significant point is that PV right now costs no more than US$2.50/gallon in the energy equation and is much more environmentally benign.
Posted by: Mark | Aug 20, 2005 7:33:30 PM
In the 1980's I saw a Saab prototype car with solar panels integrated into the roof for the express purpose of running a ventilation system while the car is parked (in the blazing sun of course). Though I was a high schooler at the time, the small sidebar made a big impression on me.
That small innovation would add little weight and cost to a vehicle reduce the need for the AC at start-up. It would also help ensure the car didn't run down the battery as long as it was parked in the sun.
Posted by: Lance Funston | Aug 21, 2005 12:51:44 PM
I test drove the Prius and thought it was really nice! Very quiet and seemed to have pretty good power.
Posted by: Jake | Aug 23, 2005 11:22:45 AM
The solar idea is a great idea...in the desert SW. Here in WNY where the lakes make there own weather all on their own clouds win most months. The cold won't help battery life and power output either. How much did that "roof rack" cost anyway? Will it work with my mtn bike and kayak up their? What's the rollover crash results look like with all theat weight up their? Hitting a moose in Canada would have that down the road 50-75 meters down the road in a ditch. I do applaud the try. Kuddos....we've had enough Tuckerism in the auto industry.
I'd like to offer another off-grid way to get electricity for the Prius. Why not use a magneto? How many of us still have a petro lawn mower that runs on a magneto? One or several magnetos could be placed on any rotating axle shaft. As long as that baby is rolling.....it can be back charging that battery pack. I'll leave it up to the engineers to figure out the particulars.....but it would work. No loss in drag, no hail damage, no kids pointing at street corners, neither heat of day or dark of night....postalman's motto. The big advantage I see it's always working while you are rolling. No expensive regenerative DC motors and controllers, no expensive PV equipment, really really cheap.
Most of these elec hybrids work really good below 30 mph and then they need a gas engine to keep them going overcoming drag and friction. If you were to use this magneto technology it just might make them all electric up to 40 or 45 mph before you need a gas assist and increase their range significantly. That'd make them
much more marketable.
Let me know how it works. I to am concidering trading to something that uses less fuel. I haven't seen anything do-all for a family with 2.4 kids as yet....I'm hoping the EPA/Ford hydraulic hybrid comes to market. The Tempo powered model Expedition got 28mpg and the VW TDI model got 33 mpg. Now put a Prius elec motor under the hood and magnetos on the axles and you've got something......I'd replace the current Explorer...with exactly that.
thanks-
shep
WNY
Posted by: Shep | Aug 23, 2005 1:50:25 PM
The real value in a hybrid/solar combo is not in car rooftop PV cells. Why use PV on a car where the angle and other factors are not optimal? Solar on garage rooftops, or better yet concentrating solar PV farms (Boeing claims a new PV cell that functions at 300+Suns) fed into the grid is far more efficient. The real value of huge fleet of rechargable hybrid cars would be in the huge amount of electical stoage capaicty they represent. Stoage capacity is the bane of almost all renewable energy. Intertie the cars to the grid with an internet connected power controller on the car to suck power off the grid when the sun is shining and the wind is blowing. Sell the power back when it is cloudy or grid demands exceed supply. This Solves both of the big problems with each system by maximizing the value of both.
Posted by: peter | Aug 25, 2005 8:05:16 PM
A lot of the comments mention the wheigth and aerodynamics of the photovoltaic panels. It should be noticed that this particular car is just a proof of concept, made from off the rack parts.
Most of the weight of the panels is the glass pane. The solar cells themselves are very thin and thus very light. In a future version the cells could be stuck to the roof and hood of the car directly, and covered by e.g. a teflon coating. In that case the extra wheight would be negliable and the aerodymics would not be influenced.
Another issue mentioned is the energy-payback-time of photovoltaic panels. It is true that it is currently releatively long (1.5 to 4 years). But it will more than pay itself back during the lifetime of the car. Moreover, the photovoltaci technique is developing rapidly. The current shortage of silicon makes manufacturers very inventive, so they use less and less material and thus less energy in producing the solar cells.
Posted by: Jan de Boer | Aug 26, 2005 11:28:51 AM
12000.00 miles a year average driving
1000.00 miles a month average driving
36.63 theoretical kwh in gallon of gas
0.25 efficiency factor of internal combustion engine
9.16 actual kwh in gallon of gas
0.13 kwatt/m2 of solar cells at peak insolation at 1kw/m2 and conv. Eff. Of .13
8.54 m2 dimensions of a Camry's top surface
1.11 kw peak power from cells covering a Camry
5.00 hrs average peak insolation US ( # of hours where the sun deliver 1kw/m2)
5.55 kwh per day from solar cells on car surface
0.88 efficiency of solar energy from cells to wheels
4.88 kwh/day of solar available (total kwh times efficiency factor for electric cars)
0.53 gallons of gas (kwh per day from car surface / actual kwh in gallon of gas)
32.88 miles a day average driving (miles per year / days per year)
23.00 mpg for car
1.43 gallons/day for an average car
0.40 kwh/mi for an average car (actual kwh per gallon / MPG average car)
0.19 kwh/mi for GM ev1
29.20 per day from Sun for GM ev1
3.00 dollars/gallon of gas
1.60 dollars a day
1565.22 $ in gas per year for average car
800.00 $ in gas per year for hyrbid
89.46 $ in gas for solar hybrid (miles per day driven – miles available daily from solar cells time days per year / MPG of hybrid)
One could object to any one of the numbers, but it takes a whole lot of tinkering to make this plan a loser. If and when gas creeps up to $5 a gallon, its going to look even better.
If 40% of our oil use is for cars, using technology like this could conceivably cut our oil use by 30%. Think about it.
Posted by: Sabin Speiser | Aug 26, 2005 11:42:27 AM
The idea of putting solar panels on garage roofs is great, but is neither here nor there in terms of making a fuel efficient car. Yes, we should have solar panels on both our garage roofs and our house roofs but not only to charge plug in solar hybrids but to have a hybrid power system in general. As the panels become cheaper and more efficient this will become a no brainer, and neighborhood roof tops will be solar panelled at an exponential rate. I know there's a lot of naysayers out there who like to put down green energy in general, but you will be proven wrong in the long run. Oil is less then two decades away from virtual irrelevance. The true reason wars are being fought over it is that big oil wants to suck as much of it out of the ground a.s.a.p while it's still worth something. I'm sure many will refute this, but in less then a decade when every single car made is a hybrid of some sort and every house has both energy efficient appliances and a hybrid power system, you'll see how obvious it was all along.
Posted by: A Brietzke | Aug 29, 2005 6:30:11 PM
I am printing out a lot of this good stuff and posting it in laundry rooms and tac boards all over town to get the message across. It's good fun and good advertising too. I like to do no nuke advertising.
Posted by: corby | Aug 29, 2005 9:15:29 PM
I think that if the major auto manufacturers researched this more they could come up with more cost effective and better solar panels. Maybe the idea of a PV paint is a good idea-red paint maybe? The solar panel does not help the styling but lets say the solar panels could be flat and flush with the roofline and put on a car like the Honda Civic. The panels themselves could be styled in some cool blue finish. Some people like the styling of the Civic better than the Prius. I think it is worth some money to research even though some say solar panels do not pay for themselves. Maybe improved materials can be found and economy of scale could bring prices down. When gas hits $6.00 a gallon maybe those solar panels will be cost effective.
Posted by: Richard P. Gunion | Sep 1, 2005 12:46:42 AM
Many of the comparisons above fail to address a major issue. Why do we want to use less petroleum/fossil fuels? Political ramifications of industrial dependence? Adverse environmental consequences of extraction and combustion? Relative expense of conversion to usable energy? Most of us could agree to pick at least one of those arguments. I would ask you to consider the merits of reducing consumption through efficient application of capital. That is how a movement obtains power; it's what will work best.
Putting solar panels on a car is not an efficient use of capital. Charging your cars batteries, (even though they will not be very efficient) with grid or renewable electricity at your home or workplace is a far superior way to reduce your fuel consumption per dollar invested. So adding storage capacity? Very Good. Turning your car into a moving solar array? Not too smart. Angle of Solar incidence (insolation) will never allow even a small percentage of production cited above.
But find a way to tie your home or business solar production to the grid, so you and your neighbor and me can create a usable energy network. Capture thermal energy and use it to heat your water or your home, maybe even cool it soon. Carpool to work. Buy efficient appliances. Drive 55 mph. My point is to not lose sight of the real goal, which is to reduce consumption of fossil fuels which are proven to have negative consequences. Debate the specifics of those consequences if you like, but if you use less, you impact the demand side of energy supply. That, my friends, is the only side that holds the cards.
Posted by: Paul Risberg | Sep 5, 2005 7:26:11 PM
I would love to do this to my '03. However, I would probably consider using flexible PV. I have also wondered why golf carts used on have yet to do this. Since there are so few trees on a golf course they would get quite a lot of sun daily and could virtually eliminate the need to plug them in every night. I would think that would be very attractive to the clubs, and would prbably pay for itself in short order
Posted by: Kirsi Enckell | Sep 7, 2005 8:56:17 PM
If I could get 5 miles per day on just one day's charge of my solar panels I could have a second car and drive each one on every other day. This would get me to work and back each day never needing to buy gas. I already drive two cars, this might be the way to go.
Posted by: John Adams | Sep 26, 2005 9:17:51 PM
imagine year 2010 maybe 2015. brent crude exceeding 150 usd (8 usd gallon), inexpensive solar panels with efficieny exceeding %50. lapp's work WILL make sense.
Posted by: D. Ünsal | Oct 17, 2005 2:07:27 PM
Offering a large selection of body kits, wood dash kits, auto graphics, nerf bars,hood scoops and loading ramps.
Posted by: Automega Auto Accessories | Oct 25, 2005 4:59:00 AM
Thanks, Steve! I have a 2005 Prius. Yours is a step in the how do we get from here to there.
Shirley E., I am a believer in the postal truck solution. Keep advocating.
I spoke to 70 5th graders today and helped them get started with Jr. Solar Sprint cars. Let's pray that they take our energy challenge on.
Posted by: Peter Hubbe | Oct 27, 2005 6:42:52 PM
This is alot like a Drag Race. At this point I think everyone, self included has checked the tire pressure, folded down the antenna, windows up and A/C off (most of the time) even speed up and slow down using the cruise control... So anything that will give me another 10% or 4% I want. If I can't buy it then I'll design and make it myself. Why? Because 30 years from now I expect to be driving the same '03 Prius and I'll look back and say 'that was the smartest thing I ever did (carwise)... My '03 has about 27k miles is almost perfect, has overall average of 54.7mpg as of today and wish I had 2 more (for kids)... Best run = home to grocery to home 17.5 miles 77mpg. Worst run = San Antonio to Rio Grande bucking a strong head wind 44mpg (note, car topped out at about 104 so it hard to keep up with traffic). Another 10%...hook me up
Posted by: Jay Fidler | Jan 8, 2006 6:04:15 PM
Tnis is ALL great, but did anyone mention the weight of the vehicle ? The 2000 kg vehicle carrying an 80 kg person! It is obvious that most of the energy is being used to move the 2000 kg vehicle from point "A" to point "B" How about reducing the 2000 kg to 1000 kg ?
How much energy would be saved ? Almost 100 years have been spent on improving the amount of energy stored in the gasoline. Does it make any sense to load your vehicle with heavy batteries ? One liter of Hydrogen stores about 3 times as much energy as one liter of gasoline. Which one would you pick ?
Posted by: John Chalotay | Jan 22, 2006 4:14:56 PM
8.54 m^2 on a camry (why not a prius?)
A prius would be 7.56m^2 (175 in long by 67 wide)
But you need to subtract the area of the glass so you can see out, so the area availabe for the array will be less but we'll run with your numbers.
4"x4" typical solar cell
828 cells needed to cover area
$9.73 per cell
$8056.44 for array
4.88 Kwh per day
Prius battery pack
6.5 Ah 7.2V 28 cells
1.3104 Kwh capacity (too small)
3.5696 Kwh more capacity needed to hold a 1 day charge
77 more cells needed
1 cell made of 6 1.2V cells @ $15.24 each in 100 unit quantity
$7040.88 for battery pack
Total cost so far.
$15,097.32
To save $710.54 in gas
4.88 Kwh /day
1781.2 Kwh / yr
price of electricty if purchased from power company
@ $0.10 per Kwh
$178.12
intrest rate on 1 yr CD 4.43%
money earned if $15,097.32 put into 1 yr CD
$682.55
Sources
http://avt.inel.gov/pdf/hev/prius2004hevamerica.pdf
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=5026&Row=476715&Site=US
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40095
http://banking.yahoo.com/res/cdrates.html
Posted by: Ryan | Mar 25, 2006 9:13:07 PM
Batteries have been a big part problem. They are heavey, take long to charge and have a short life cycle. Toshiba recently announced a new Lithium Ion battery that charges to 85% capacity in ONE minute, is much lighter, smaller and lasts much longer. You could fill your batteries with electricity FASTER than you can fill Gasoline. Thanks to nanotechnology this is way more efficient.You could drive from Florida to new York just on electric. Just need a 60 second plugin along the way. I could imagine having 2 sets of batteries. One stays at home and recharges off your roof top PV panels all day. You come home at night and then transfer the electricity to the car batteries. Neuclear plants supplying non-fossil fuel to run the grid would help global warming also.
You will see other big companies like Sanyo and Panasonic come out with these batteries also. You will see fully electric(non-hybrid) cars and trucks by the end of 2006 in China and Japan and they will weigh much less than the heavey pigs you see today.
As oil consumtion begins to drop so will the price This will start end of this year.
Posted by: Don Chambers | Apr 26, 2006 11:57:14 AM
Why do this to a Prius? Doesn't the alternator in an ordinary car have generate hundreds of watts anyway? You have to power the radio, running lights, climate control, water pump, fuel pump, computer, ignition, etc. That's gotta be at least 270 watts of load before even getting to the battery.
So, instead of trying to use PV to charge the batteries in a Prius, seems it would be more practical to use PV to run the electrical system in a Camry. Or am i mistaken?
Posted by: satyen | May 7, 2006 10:17:01 AM
From the main article: "For June and July in Kingston Ontario, about 6 kWh of energy from the sun strikes each square meter of horizontal surface."
It has already been pointed out early on in the comments, but I will say it again as it has not been updated: The sun gives out 1 kwh per square meter not 6.
It is unfair to give people the impression that solar power is 6 times as good as it really is currently (even though I love solar power).
Posted by: LegendLength | Aug 3, 2006 8:44:59 AM
Thank you, everyone for letting me know that I am not the only person thinking up "crazy" ideas like putting PV on a car! I live in Detroit (spelled INTERNAL COMBUSTION ENGINE) and this all seems very far off. But I am learning and hope to have an "off-the-grid" vehicle within 5 years. I even wonder about hood scoops with wind turbines that assist PV in recharging duties. Is this crazy, too?
Thanks, again.
Posted by: brian k | Nov 5, 2006 5:53:52 PM
One of the weak points of the Prius is that if you dont use it at least once a week the 12 volt battery (which if i understand correctly loses its charge because it trickle charges the "electric" battery) will discharge and you have to take the prius to a garage to reboot the computer. So you have to run your car for 10 minutes every few days. To me this is a big weakness of the Prius and very incovenient.
Surely the solar panels can offer a solution to that? wouldnt it be possible for them to keep the 12 volt battery charged up while i am away not using the car? anyone have any instructions on how to do this?
Posted by: marcus | Nov 13, 2006 3:22:19 AM
Satyen,
The 6 KWH/m2 = 1 July DAY of sun energy.
The 1 KWH/m2 = 1 HOUR of sun energy.
The article is correct.
Everyone,
This is a VERY informative thread. Thanks ! Hopefully humans will soon become as competetive about conserving energy as they are about almost everything else.
Posted by: jim | Jan 21, 2007 6:36:48 AM
What sun is shining on your planet?
On planet earth, solar irradiance = 1 kwh/m2. According to the article, the pv panels will not charge while parked, the PV contributes only while moving. Therefore, 6 Kwh per day is not realistic. More likely, a 1 hour commute will net you about 200 watts (1 kwh x 1 meter x 20% efficiency), or about the energy required to move you 1 km. Of course, considering that you are (hopefully) driving at 60 km/h or more, your net increase is 1/60 - or about 1 mpg.
Further consideration...who commutes to and from work at solar noon when the sun is strongest? Expect about 10% of the pv output while the car is actually commuting (ie 7 am sun is much less powerful that noon sun). So your net increase is about 10% of 1/60...or about 0.1 mpg.
So what if you enhance the system to charge a battery pack while parked? Well...how many vehicles are parked all day in the sun - ie not in a parking garage or shaded by the sun?
Conclusion...Put the panel on a building where it's all day in the sun and it's not so complex as automotive engineering! Spend the money on a fixed system that is more logical.
Also, it is very necessary to be educated or we all look silly...and being wrong once lets all the naysayers reject other more logical solutions. The information to critically analyze this article should be known to all, or googled in about 1 minute...
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Posted by: ashlee | Oct 31, 2007 5:03:13 AM
ok
this whole thing is a good idea and i really didn;t read through proporaly so if i am stating something that has been mentioned well then sorry but andy way
ok so solar powered car is a great idea but if you take it up to the next level u could make a solar powered car WITH a rechargeable battery so when its not sunny you can still move incase the sun goes away in the middle pf the day!!
Posted by: meghs | Nov 19, 2007 1:37:09 PM
ok
this whole thing is a good idea and i really didn;t read through proporaly so if i am stating something that has been mentioned well then sorry but andy way
ok so solar powered car is a great idea but if you take it up to the next level u could make a solar powered car WITH a rechargeable battery so when its not sunny you can still move incase the sun goes away in the middle of the day!!
Posted by: meghs | Nov 19, 2007 1:38:01 PM
Hi Sir,
Hope that you are doing more than fine .
well im asking for Panasonic Prismatic NiMH , it consist of 6 cells , it is 7.2 volt , 6.5 Ah , it is electro-thermal modeling , it is used for hybrid cars .
can you help us in this , and where we can find this part .
please advice .
best regards,
Loai
Posted by: loai qdairat | Nov 24, 2007 7:05:04 AM
i got patents for wind turbine electrical genarator and exhaust gas turbine eletrical genator for hybrid cars ,with novelty.if you need contact me
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i h8 u all
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Posted by: titili wink | Apr 23, 2008 8:00:47 AM
