Groups > sci.electronics.design > #519131

Re: Can a small photocell panel be connected to a flashlight type rechargable battery?

From	Jasen Betts <jasen@xnet.co.nz>
Newsgroups	sci.electronics.design
Subject	Re: Can a small photocell panel be connected to a flashlight type rechargable battery?
Organization	JJ's own news server
Message-ID	<pps00q$k4o$1@gonzo.alcatraz> (permalink)
References	(3 earlier) <0k00sdt1dmep23fc5f6gcdnu6m89bjl52h@4ax.com> <ppp9tl$cpm$1@gonzo.alcatraz> <g8g1sddcro14rbn1rugn0396q4ke8lsqth@4ax.com> <ppqsde$54m$1@gonzo.alcatraz> <qtg2sd5801kbql41j977spdvcekgntubau@4ax.com>
Date	2018-10-13 05:32 +0000

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On 2018-10-13, Jeff Liebermann <jeffl@cruzio.com> wrote:
> On Fri, 12 Oct 2018 19:24:30 -0000 (UTC), Jasen Betts
><jasen@xnet.co.nz> wrote:
>

>>Same energy in (full sunlight minus that reflected), same electrical 
>>energy out (nil). Therfore same amount of heating.  With the open circuit 
>>panel it's conduction through the diode junctions of each cell (hole-electron
>>recombination at the junction) that produces the same heat energy as the
>>resistive heating in the shorted panel, If you want to reduce the
>>self-heating of a panel electrically you connect it to a load (preferably MPPT)
>
> I was under the impression (apparently false) that a cells internal
> resistance was lowest at the MPP and increases on either side, which
> reduces the efficiency of the cell at either extreme (open and short
> circuit).  Therefore the self heating would be at maximum at the MPP
> and less with an open or short circuit.  I guess that's not true,
> although right now, I can't see why.

starting from MPP

at lower current you get less power out because P=VI and reducing I
reduces P

at higher current increasing the voltage available available because
you can't exceed the cell's quantum efficiency, the cell just runs out
of available electrons.

>>Maybe they do change colour, the hole-electron thing could make
>>inf[r]ared light...
>
> That would be interesting.  Thermochromic solar panels, where I could
> actually see the hot spots and failed cells without having to borrow
> an expensive FLIR camera.

I dont know if they would be visible to a silicon photoelectric image
sensor or not it seems the photons would be near the quantum threshold.

-- 
  Notsodium is mined on the banks of denial.

Thread

Can a small photocell panel be connected to a flashlight type rechargable battery? oldschool@tubes.com - 2018-10-11 00:32 -0500
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? <698839253X6D445TD@nospam.org> - 2018-10-11 06:10 +0000
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? tabbypurr@gmail.com - 2018-10-11 05:51 -0700
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? George Herold <gherold@teachspin.com> - 2018-10-11 06:18 -0700
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? dplatt@coop.radagast.org (Dave Platt) - 2018-10-11 10:39 -0700
    Re: Can a small photocell panel be connected to a flashlight type rechargable battery? bitrex <user@example.net> - 2018-10-11 22:41 -0400
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-11 12:14 -0700
    Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-11 22:34 +0000
      Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-11 19:31 -0700
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-12 05:02 +0000
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-11 23:05 -0700
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 09:08 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:36 -0700
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 10:20 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 10:37 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:41 -0700
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 10:04 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-12 19:24 +0000
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 18:26 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 22:27 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-13 05:32 +0000
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-12 02:12 -0500
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:15 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-13 15:14 -0500
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-14 20:34 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-15 20:39 -0500
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-15 21:28 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-16 18:08 -0500
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-16 16:29 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-16 16:47 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-17 02:23 -0500
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 09:23 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:48 -0700
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 17:57 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 22:19 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-12 19:56 +0000
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2018-10-12 07:36 +0000
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? George Herold <gherold@teachspin.com> - 2018-10-12 05:59 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2018-10-12 13:06 +0000
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:18 -0700
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 09:44 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? <698839253X6D445TD@nospam.org> - 2018-10-12 17:57 +0000
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? whit3rd <whit3rd@gmail.com> - 2018-10-12 23:23 -0700
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-13 04:56 -0700

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