Toyota secretly developing solar powered car.

Re: Toyota to build solar cars

The picture is missing, can you re-post it?

 

Re: Toyota to build solar cars

You're figuring out the Tesla secret plan

Tesla Motors - think

 

No way! No wonder they're keeping this secret (you know, with big headlines and all). This is so cutting edge, that I really don't think it could ever work. Powering your car with PV on the house roof? No way! :yawn:

Yikes. So the Prius is a bridge back to where we were in 1996? 15 years after we had solar-powered Toyotas on the road, we're trying to build a bridge back there? And in secret? I'll say it again (because I like it): Yikes.

 

Re: Toyota to build solar cars

Indeed. A big waste of resources to put a product that'll be severely under-utilized on a disposable host. We pay for PV in money, energy and pollution to build them... we need to use them in the most effective way - and that is on the roof, oriented properly and never in the shade. Put them on a car, and the panels will out-last the car many times over, and will very rarely be in the optimal position to generate.

 

You can make a car go down the road, but can you have a passenger, and how fast?

Motor Trend (i think) used to measure road horsepower, and the rule of thumb that sticks in my mind is that it takes about 20 hp at the rear wheels to propel a big car (think a Crown Victoria or similar) at around 70 mph. Assuming the photovoltaic system efficiency is (extremely optimistically) 18%, the solar panels need to collect 20 / 0.18 *746 = 83 kW. Using the peak power figure of 1000 watts of solar energy per square meter, there must be 83 square meters of solar panel on one car. NOT FEASIBLE.

What might be feasible? If we say it will be a small car with half the frontal area, this reduces by 50% to get an area requirement of 41 sq m. If we say it is a hybrid car that can drive on solar only up to 45 mph, we scale the power down from 70 mph by the square, and get another 41% reduction, the area requirement is now 17 sq m, still a square surface around 4 meters on a side.

To get something that at least is not bigger than a car, we need a width of 2 m and a length of 4 m, for 8 sq m of area, still under optimum insolation and angle of incidence conditions. This car would scale down its electric speed (maximum electric speed) by (8/17)^2, to get a maxiimum electric speed of 10 mph. This is based on a fairly draggy car body, no special aerodynamics.

So it's going to be really hard in terms of basic physical constraints to ahve a production photovoltaic passenger car that has practical utility.

Now if a 500 watt day after day output solar system could be put on a car, what could we do? Run the A/C fan, running lights, nearly all the interior electronics (high-powered audio system could be too thirsty). It would also be nice to store energy to support night operation.

Recharge the propulsion battery? only very slowly. 500 watts output would deliver a hp-hour (746 watt hours) in 1.5 hours. If you drive for an hour at 10 hp, you need to provide 15 hp for an hour to replenish the battery. This energy collection requirement gets us back to the back yard sized solar arrays, which won't be carried on cars.

It's getting late, but I feel strongly the application of solar panels on cars for propulsion energy is very limited. there may be more opportunity to recharge battery powerd cars from building-mounted PV arrays.

Road Fan

 

If the idea is to recharge a pure EV from house roof panels, we run back into the issue of storing a whole driving mission worth of energy in a secondary battery. The genius of the hybrid concept is that the battery capacity is greatly reduced from this stringent requirement by using high-density gasoline to store the energy, and to provide it by converting this energy in an IC engine-generator.

I expect Toyota, now that they have a proven architecture, will incrementally evolve it to include some solar input, taking baby steps that are easy to prove feasible. This has been their apparent technology strategy for several decades.

 

Sorry Darell I should have said a mind bridge for the general car buying public. I guess the rest of my post might have made that clear but, oh well.

 

This is it for me, exactly, as well.

 

Solar charged 5kWh Plug-in Prius will be capable of 100 MPG. Compare to a 25 MPG standard car, only 1/4 of the energy will come from the gas station. We are almost there... probably within next gen Prius.

Hymotion L5 upgrade = $10k
1.2kW Solar panels installed = $5k

For $15k, you can double the current Prius MPG. If Toyota/Panasonic/Sanyo can offer a solution for half this price, we will have a lot of buyers.

 

Where can I get 1.2kW of solar on my roof for $5K? Minimum price I have found is $12.5K AU dollars or about $9,000US installed on my roof.

 

Re: Toyota to build solar cars

Solar competition cars like the one shown or the University of Michigan one (winner for the past few years) do have batteries. PV power systems benefit greatly from a battery and capacitor bank for stabilization. Can't say for sure about the regen braking, but as a power electronics engineer, once you have four-quadrant inverters and a battery, regen braking is mainly a matter of software and possibly some more sensors.

One of the main advantages in the solar performance of these challenge cars is the extremely small frontal area, especially compared to a standard car. That alone reduces air drag and hence the propulsion power requirement by a considerable factor.

 

This bus runs on nothing but solar energy.

There are solar cells on the roof of its garage which put power into the grid which offsets the power used by the bus when it charges overnight.
Technical Specifications
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn][FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Dimensions:[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Length – 10.42m[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Width – 2.48m[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Height – 3.06m[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Weight – 11,480kg (Curb)[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Capacity:[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Seated – 25[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Wheelchair – 2[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Total – 27[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Performance:[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Motor power nominal – 36 kW[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Motor power peak – 160 kW[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Charge power – 36 kW[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Speed – 76 km/h[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Gradability – 12.5%[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Battery System:[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Type 11 modules Zebra Z36-371-ML3C-64[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Rated energy 261.8 kWh[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Accessible energy 235.6 kWh[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Roof-mounted solar PV Uni-Solar PVL-68 W (peak)[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Fast Booster Charger (located on Franklin St, outside Adelaide Central Bus Station):[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Power – 70 kW[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Input – 400V 3-phase AC 100a[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]Output – 386V DC 200a 70 kW[/FONT]
[FONT=Frutiger LT 47 LightCn,Frutiger LT 47 LightCn]1 minute of charge = 1 kilometre [/FONT]
http://www.adelaidecitycouncil.com/scripts/nc.dll?ADCC:STANDARD::pc=PC_151048[/FONT]

 

You have made the common mistake of assigning far too much perceptive ability to me. I'll let it slide this time.

 

Well, while we're showing pictures - here's one too. Same deal. Solar on the garage roof makes more than the car consumes.


Car model first built in 1996. This particular 2002 example is most often found in MY garage.

 

Are we still talking about "in the mind" as well here? Because, really, it is the other way around. Battery cars begat the Prius... and we're now slowly working out way back to battery cars. (not in the mind, but in the physical world).

 

you cant ... some countries/states cover half of the expense, hence 5k price i believe.

I dont really car how far ahead solar would be and what exactly would it end up being...

What I car about is that it will advance the technology and pour some R&D money into it, and also more R&D into batteries.

1st generation product of any kind can not be everything we want it to be... but if we did not get Gen1 Prius in '99. we would not get upcoming 2010 Prius anytime soon. So you have to start somewhere, even if it is just roof cells powering A/C and auxillaries.

 

Funny how moving a dot just one space can make such a big difference.
Please note I have corrected the cost of a grid connected 1.2kW PVA from $1.25K AU to $12.5K AU. Oops!

There are rebates available ($8K AU) for households with income below $100K AU/year last financial year, unfortunately I am just over the threshold. How stupid is that?

 

I figure that with three of us in the EV, crossing the bridge should be a net money-maker for us!

Oooh. He'd be so proud that you think so highly of him. He's a rescue mut from our local SPCA. His mom was mostly Queensland Healer (judging only by the looks) and dad was never found. He's 11 now, and we've had him his whole life.

I wish... but I don't hold the copyright.

This totally depends on how you define efficient in this case. You've paid for the PV. You pay for the extra weight and air resistance of having on you car - even when you drive at night, in shadows, etc. I still contend that there is NO practical reason to attempt to supply your traction power with PV directly on the vehicle. It doesn't pencil out in energy credit, or financial credit.

 

Those are the best dogs of all.