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prius portable solar panel

Discussion in 'Gen 2 Prius Accessories & Modifications' started by djphill, Aug 19, 2008.

  1. djphill

    djphill Master of The World

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    If i were to leave a solar panel on the dashboard when i park, would i collect any energy. If so, if it were plugged into the cigarette lighter would it help the mpg at all.
     
  2. efusco

    efusco Moderator Emeritus
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    1) Yes
    2) No...unless you modify the cig lighter/power point...and even then it's pretty questionable.

    elaborated...
    1) Sure, a solar panel will collect some energy..but about the biggest you're going to fit there is about a 5W and most that are sold for cars are about 1.8W...so it'll collect energy, but not a lot relative to the Traction battery.

    2) Both front power points are disengaged when the car is turned off. The lower one under the dash can be pretty easily modified to be 'always on'. But even so the energy will go only to the smaller 12v battery. While that can be nice to keep it topped up, esp. when the car will be parked for a long time it is unlikely to make any measurable impact on fuel economy. I have one of those 1.8W panels and sometimes connect it directly to my 12v battery (with alligator clips) when I leave the car parked for over a week at the airport.
     
  3. djphill

    djphill Master of The World

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    I was also planning on using a small solar panel to charge my cellphone and ipod.
     
  4. qbee42

    qbee42 My other car is a boat

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    That makes more sense.

    To expand on Evan's comments, it's not an easy process to charge the HV traction battery in a Prius. I could build a solar charger that would work with the HV battery, but it would take me several days of design work, a lot of expensive parts, and then would only make a tiny, tiny difference in the level of charge. If you really want to do that, put the panels on your house where they can be big enough to make a difference.

    Portable panels are great for small appliances and topping off 12V systems, so I like your second idea.

    Tom
     
  5. dwreed3rd

    dwreed3rd New Member

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    What about a folding solar panel windshield shade to trickle charge the 12v? :noidea: Some assembly required! (modification).
     
  6. efusco

    efusco Moderator Emeritus
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    It's a cool idea, but would be expensive and probably would be larger than necessary for the job. Why not a convenient $25 1.8W panel available anywhere?
     
  7. David Beale

    David Beale Senior Member

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    Solar panels of this type are about 10-15% efficient. If you want to shade the windshield with one it would probably be inside (they are expensive and you don't want it walking away!). So the panel would still heat up the interior of the car with 85-90% of the effect of the unshaded sun.
    It -would- be able to keep the 12V battery charged, keeping in mind the 12V battery is probably fully charged when you shut the car down. You -could- trickle charge something else as well. Panels that small would put out up to about 200 mA - you loose a lot of energy through the windshield, and assuming you park the car facing due south or wherever the sun is most of the time you are parked. It drops off fast when you are not facing the sun.

    It's a neat idea, just not very practical. The panels that go on the Prius roof are better, but only a little. They are expensive and provide only marginal power, and it goes to the 12V system, which doesn't need it!
     
  8. dwreed3rd

    dwreed3rd New Member

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    David, Thanks! I particularly get the point that the panel would absorb the heat into the car instead of reflecting it back out the windshield, defeating the main purpose of using it in the first palce. Good thinking.
     
  9. Stefx

    Stefx Member

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    How about this idea:

    Go in a big parking lot, ask a friend to be at the wheel. Get out and push the car as hard as you can. You can probably have a 200W output for 20-30mins, you'd charge the traction battery. This would be a lot more useful than a little solar panel, and you'd lose weight, therefore improving your mpg further.
     
  10. carz89

    carz89 I study nuclear science...

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    Awesome! Classic! I must try it and measure the charging current with my scangauge.

    Taking the math one step further, 200W for 30 minutes equates to 400 watt-hours, which equates to 344 kilocalories (344 Calories in nutrition speak). Not a bad workout!
     
  11. Stefx

    Stefx Member

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    There's a few businesses idea

    -Develop a threadmill or stationary bicycle that would recharge a battery
    -Instead of carwash for financing for the local school's volleyball team, offer Prius owners to push their car around the parking lot by 5-6 students for a few dollars, to recharge their battery
     
  12. dwreed3rd

    dwreed3rd New Member

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    They already have the treadmill. :doh:
    While You're at It, Why Not Generate A Little Electricity - WSJ.com

    But how about this for the next Prius Club Meet? :dance:
    Power-generating dance floor hits UK club - Engadget

    :whistle:
     
  13. JoesMorgue

    JoesMorgue Junior Member

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    BIG Problem: How would you do this?

    Drive, the car would want to creep on its own. Neutral, no charging effects. The weight loss adds up, so I cannot argue with that.

     
  14. carz89

    carz89 I study nuclear science...

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    Perhaps you need to get the car moving at some minimum speed where regenerative braking begins (I think below 7 mph, only the friction brakes provide any braking). Once the car is moving, say 10mph, then use human power to keep it at that speed while simultaneously lightly feathering the brake to produce some regenerative braking. Of course the engine would have to be complete warmed up so that the engine doesn't kick in.
     
  15. ScubaGypsy

    ScubaGypsy Live Free & Leave No Footprint

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    I have a Sun Catcher Expedition folding solar panel that is left over from a project that is now completed (and it worked very well). This single crystaline panel has a reported peak output of 25.1 W with a DC cord female outlet (12 Vdc cigarrette outlet). I'm thinking of placing this panel inside of my Prius windshield when I leave my car at work or the airport for extended time as I have had a dead starting battery in the past. I'd like to hook-up to my Prius through an always on 12 V outlet modification. However my experience has been that when the panel is not providing power (at night or when cloudy/rainy/snowing) then it actually absorbs power. I recently tried charging a Garmin GPS inside of my car and found that it actually drained the battery at night. So I thought that I could add in a small solar charger like the Morningstar SunGuard SG-4-12 solar charge controller. Unfortunately when I have wired this up and placed the panel outside in direct sunlight, I'm not seeing any voltage registering at the backside of the controller yet I am seeing it at the input.

    So my questions are, 1) is there a minimum current draw required for the charge controller? and 2) I'd like to put together a DC male plug to DC male plug cable with a controller placed in between, is this the most efficient method for using the panel to provide power for the Prius?

    Appreciate any insights that can be provided.