Featured Toyota testing new solar powered Prius

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Prius Pete, Jul 5, 2019.

  1. alanclarkeau

    alanclarkeau Senior Member

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    Or put it on rails like my HYBRID Avatar (which is a Union Pacific steam turbine-electric engine 1939 - only 2 were built by GE). They were deemed unsuccessful and too complex, dismantled in 1943.

    So we did have a coal/electric hybrid. I wonder if it would have been more successful covered in SOLAR panels.
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    To be honest when I saw the thread title I was briefly hopeful that Toyota was offering a combo package of a pluggable car + a home PV system sized to offset charging usage, all bundled up with easy financing.

    The reality- a car with some solar panels on it- isn't... uninteresting, but I had been hopeful that the overall program was something practical today rather than a preview of something 2-4 decades out.
     
  3. bisco

    bisco cookie crumbler

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    a home pv system with a car, might sell a half dozen :cool:
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Yep, but that's pretty much the soul of the Prius- cool stuff that almost nobody wants to buy.
     
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  5. bisco

    bisco cookie crumbler

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    how about an aftermarket car cover covered in cells (y)
     
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  6. fuzzy1

    fuzzy1 Senior Member

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    And if you have a very well lit garage, you might even be able to crank that 860 W PV set all the way up to 10 W!

    ----

    IIRC, normal indoor office lighting is around 200-500 lux, a few places would be pushing 1000 lux. PV solar cell output ratings are measured in standardized direct sunlight, in the 100,000 lux range. Indoor light energy harvesting means tiny outputs. (BTDT in product development.)
     
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  7. fuzzy1

    fuzzy1 Senior Member

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    PriusChat already has far more members with such systems. Even if ad hoc, not pre-packaged.
     
  8. Rmay635703

    Rmay635703 Senior Member

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    A lot of businesses have a fresner lense tunneling outside light through a small pipe or fiber optics into the office for “daylight”

    I have no doubt a similar concept would work in a garage, could even aim the light to your spot
     
  9. Prius Pete

    Prius Pete Active Member

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    I'll bite.

    Say the car's panels charge the 8 KWhr battery every day. Say power costs $0.10/KWhr. That's $292/yr or $4380 over the car's 15 year life. A 860W panel could soon cost under $860. So it could, under ideal conditions, pay off very well. And that's assuming the sun is replacing cheap grid power rather than expensive gasoline.

    Of course the actual pay off depends on what Toyota charges for the option, how much you pay for electricity and gas, how much sun the car gets, what your driving patterns are and how long the car lasts.

    In the UK, Toyota the existing solar roof option costs £1,500 for about 180W. It's probably hard to make that pay off.

    There's nothing to prevent you from also putting solar panels on your house, if you own a house and that house has suitable solar exposure. A solar car can harvest energy beyond what falls on your property, e.g. sunlight falling on the parking lot at work or on the road driving to work.

    If you live in an apartment, where else are you going to put your solar panels if not on your car parked on the street? Your hat?
     
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  10. drash

    drash Senior Member

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    Three positives that can be seen from this article:

    1) The fact that Toyota is willing to use an exotic solar material (normally relegated to space applications) means they’ll mass produce these solar cells and ultimately bring the cost down for everybody to use. And let’s not forget you are putting Toyota and Sharp together to tackle this issue.

    2) Triple junction solar cells are noted for their efficiency in absorbing sunlight from non-direct angles. Studies have shown they lose about 2% when mounting these horizontally versus pointing them directly at the sun (https://pdfs.semanticscholar.org/2a72/d802dad3b637be2d106489e237c8886ad358.pdf#page53). While everybody remembers the huge sails for the space station and the Hubble, the fact is most solar cells on spacecraft are mounted directly on the body of the spacecraft.

    3) These are much lighter than batteries and even used to supplement the HVAC system will help. Sharp’s triple junction thin film solar cells weigh about .33grams/27cm2. That’s not a typo, yes it’s 0.33 grams. They have to lift these in space so weight is an issue.


    Unsupervised!
     
  11. austingreen

    austingreen Senior Member

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    I think this is where it falls down. They are talking about what at most 5 kwh per day on a prius prime? How much does batteries weigh? The pack in a telsa model 3 would require about 12 kg for 1 kwh. NOw you want to what not have a 8.8 kwh battery (currently in prime) because you think it will magically store the energy, or you only use that much. The larger solar 1 talks about 12 km/hour charging from 5 square meters. Only way you save more than 1 kwh of battery is if you limit speed to about 10 km/hr (6mph). Having the panels really doesn't reduce battery needs much, but it will add to cost. My guess is for the same price as these on the prime, they could give it a 12 kwh battery, and you could add 1 kw of solar to your roof ;-) where it will last 30 years.

    Its probably good for r&d for some trickle charge factor if you aren't driving your car for days and its out at say an airport parking lot, but not much real world with today's tech prices.

    And that's the problem, my guess is this will cost toyota at least $2000 USD to produce and they would need to charge more for dealer mark up, profit, and paying down R&D. I doubt that you would average even 5 kwh/day, but it might break even if toyota keeps costs down and you keep the car over 10 years, but both of those are not likely selling points.
     
    #31 austingreen, Jul 6, 2019
    Last edited: Jul 6, 2019
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  12. fuzzy1

    fuzzy1 Senior Member

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    An 860 W panel simply cannot provide 8 kWh in a day from natural sun unless it is on a sun-tracking mount to keep it squarely pointed at the sun all day, or is boosted by adjacent reflectors to concentrate more light on it. Even then, it doesn't take much shade or clouds to fall short.

    Winter is also a problem. At my latitude, we have months were even with a perfect mountain-top solar tracker in perfect weather, the sun simply isn't up long enough to produce that much.



    Posted via the PriusChat mobile app.
     
  13. Prius Pete

    Prius Pete Active Member

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    And they take up zero interior space.

    Make the windows out of this stuff: Transparent Thin Film Glass Solar Panel For Window - Buy Bipv Module,Thin Film Pv Panel,Flexible Amorphous Silicon Thin Film 10% Transparent Solar Panel Product on Alibaba.com

    Slap this stuff on the roof and hood: New Energy And High Effcience 110w 150w 190w 220w Flexible Thin Film Solar Panel - Buy Flex Solar Panel,Thin Solar Panel,Flexible Thin Film Solar Panel Product on Alibaba.com

    I think Toyota realizes that these flexible thin film solar cells are a game-changer.
     
  14. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    If you start from the various shapes we make cars and trucks today (because they're already the right shape for many factors) and plaster them with these new PV panels, I wonder which shapes work best relative to their energy needs?

    Minivans with their huge roofs and sidewalls? Malldozer trucks? (nothing in the bed)

    I like what @drash picked up- if Toyota is serious about this the availability will go up and the cost will go down. And then the shape doesn't really matter so much, it's just free energy.

    Plus body shops will need to hire BSEEs to ding 'em out. :ROFLMAO:

    Think I might have to see about starting a junkyard... in a sunny spot... near a substation... You know, for when everyone's done driving 'em.
     
  15. drash

    drash Senior Member

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    I’d have to agree. But maybe they are also testing a rear view mirror ala Range Rover’s ClearView where no matter what is in the back seat and/or hatch area blocking your rear view, flip a switch and it’s like nobody’s there. I think the point Toyota is trying to make is everybody can take advantage of using solar, even if they don’t have an opportunity to put it on whatever roof they are living under. Take my driving, I average about 4.4 miles/kWh because I sometimes just drive the car, unlike some members of PriusChat (like @Salamander_King) who are hitting 7’s to 9 miles/kWh. But let’s go with an average of 4.2, that’s what, 238 W/mile. If your solar roof (skin?) is putting out 860W, I’d assume you are in the plus over your trip, even if you using A/C and/or heat.

    Let’s keep in mind this is a test vehicle that’s been in use from 2016 and will be going to 2020, so it’s not like it’ll appear on this year or even next year’s model. But I applaud Toyota for taking this to the next step and since they are using 2016 technology, it can only get better as it involves both Sharp and Toyota. Also this is being tested at the Aichi test center and not Arizona and 860W in Japan is pretty impressive.


    Unsupervised!

    [edited for clarity]
     
    #35 drash, Jul 6, 2019
    Last edited: Jul 6, 2019
  16. bisco

    bisco cookie crumbler

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    or, it's just a publicity stunt
     
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  17. drash

    drash Senior Member

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    Of course it is. Toyota is throwing down the gauntlet by telling everyone, we’re not just putting silicon solar cells on our cars. We’re putting on triple junction thin film cells and this is what we got. Why should they be the only ones shouldering this cost? If they can goad others into doing the same thing this will bring down the cost even faster.


    Unsupervised!
     
  18. bisco

    bisco cookie crumbler

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    better yet, convince governments that taxpayers should shoulder the bill
     
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  19. GasperG

    GasperG Senior Member

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    This could work as a sun shade problem for people that don't have garage and can't charge at home. Even manual deployment could work if it means less heat in the cabin.
     
  20. fuzzy1

    fuzzy1 Senior Member

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    Say what? That isn't how I read it.

    Figure 3.14 shows the triple junction cell dropping off from 23% at its best to just 17% at the end of the testing day, while the silicon cell actually improves from 11 to 12%. Unfortunately it doesn't show solar incidence angles for any of these data points. And doesn't go all the way to sunset.

    The next figure does show angles: "Figure 3.15 displays the degradation of the conversion efficiencies under different angles of incidence of the radiation of the sun over the ATJ solar cells. The results were obtained from four distinct orientations, which are: pointing to the sun, horizontal, and zenith angles of 34º and 44º facing to the north (Azimuth 0º). The experiment was performed between the 15:05 and 15:16 hours during the testing day.
    upload_2019-7-6_23-32-46.png

    Figure 3.15 confirms that the angle of incidence of the direct sunlight beam over the ATJ solar cells has a significant effect over the conversion efficiency. This factor explains the degradation of the efficiency of the ATJ solar cells along the day in horizontal position during the early and late hours. "


    I'm seeing a 3% efficiency loss at 22 degrees off normal, 8% loss at 32 degrees, and 15% loss at 39 degrees off. This is in addition to the required cosine-theta loss of raw incident power.

    If you are getting your 2% from Figure 3.16, as the drop from 25 to 23, then be careful how you read it. This chart terminates quite early, several hours before Fig. 3.14 ends and before the solar incidence angle gets steep. And the way I figure, dropping from 25 to 23 counts as an 8% drop, not 2%.
     
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