Alt-BEAM Archive

Message #09883



To: beam@sgiblab.sgi.com
From: "FCO Enr." fco@total.net
Date: Tue, 08 Feb 2000 02:44:59 -0500
Subject: [alt-beam] Solar power question


greetings,

I have a very silly question for everyone.

1 SCPD solarcell outputs .4volts and 0.0014amps. We can fit
25 of these/square inch. 144 square inches / square foot.

25*144 = 3600
3600 SCPDs wired together would be 1440 volts and 5.04 amps

That is quite a lot of power for 1 square foot. Theoretically if I use
a High efficiency output Lamp such as this:

SADelite Lamp (http://www.northernlight-tech.com/eng/products.htm)
10,000 lux
Power : 120 Volts/60 Hz, 0.75 amperes (85 watts)

On that 1 square foot surface I would not only have enough power to
run the lamp off of, but I'd have some to spare. Meaning after starting
up such a lamp I would be producing power.

Now this is totally ludicrous I know I am missing something here..
but what is it? I mean a 12x12 foot area on a rooftop lined with these
cells would produce enough power to power my entire house. EASILY.

518400 SCPDs (definitely not cheap considering that's JUST the SCPDs
and no boards or anything).

518400 x 0.4volts 0.0014 amps = 207360 volts 725.76 amps

A couple of deep cycle batteries and a power switchboard and this
would be one highly efficient solar power plant (for the rich mind you).

What makes the small SCPDs so much more efficient than regular
solarcells? Or are they only on paper? Do they actually catch less light?
What am I missing here?

Andy



9884 Tue, 08 Feb 2000 02:00:59 -0700 [alt-beam] Re: Solar power question beam@sgiblab.sgi.com Dave Hrynkiw At 12:44 AM 2/8/00 , FCO Enr. wrote:
> 1 SCPD solarcell outputs .4volts and 0.0014amps. We can fit
> 25 of these/square inch. 144 square inches / square foot.
>
> 25*144 = 3600
> 3600 SCPDs wired together would be 1440 volts and 5.04 amps

Close, but not quite.

It would be 1440 volts at 0.0014amps if you string them all up in series.
OR, 5.04 amps at 0.4V all wired in parallel, but not both at the same time!
So your power rating would be 0.20 watts per square foot - that sound more
realistic?

Regards,
Dave


---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com



9885 Tue, 8 Feb 2000 09:42:04 -0000 [alt-beam] Re: Solar power question beam@sgiblab.sgi.com Robert Selby I seem to remember a warning that while it was OK to connect them in series
to get extra voltage, it was NOT ok to wire them in parrallel.

Something to do with manufacturing tolerences and the output voltage.

If you want to wire them in parrallel you have to use diodes to prevent
reverse current.

When the sheets are made and cut to provide a given current it is OK since
it
is all from the same batch.


Regards,
Bob

------------------------------------------------------------
Robert Selby email : rselby@madge.com
Senior Development Engineer, voice : +44 (0)1753 661 243
Madge Networks Ltd, fax : +44 (0)1753 661 888
Wexham Springs,
Framewood Road,
Wexham, Slough
SL3-6PJ
England (UK).
------------------------------------------------------------


>> -----Original Message-----
>> From: Dave Hrynkiw [mailto:dave@solarbotics.com]
>> Sent: 08 February 2000 09:01
>> To: beam@sgiblab.sgi.com
>> Subject: Re: Solar power question
>>
>>
>> At 12:44 AM 2/8/00 , FCO Enr. wrote:
>> > 1 SCPD solarcell outputs .4volts and 0.0014amps. We can fit
>> > 25 of these/square inch. 144 square inches / square foot.
>> >
>> > 25*144 = 3600
>> > 3600 SCPDs wired together would be 1440 volts and 5.04 amps
>>
>> Close, but not quite.
>>
>> It would be 1440 volts at 0.0014amps if you string them all
>> up in series.
>> OR, 5.04 amps at 0.4V all wired in parallel, but not both
>> at the same time!
>> So your power rating would be 0.20 watts per square foot -
>> that sound more
>> realistic?
>>
>> Regards,
>> Dave
>>
>>
>> ---------------------------------------------------------------
>> "Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
>> that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
>> 2 vowels. Pronounciation? _SMITH_".
>> http://www.solarbotics.com
>>



9886 Tue, 8 Feb 2000 06:45:49 -0500 [alt-beam] Re: Tutorial "Richard Caudle" > Anyway, tutorials are great for anyone. There haven't been any for heads
as
> far as I know.
>
> dennison

www.geocities.com/frankendaddy/BEAMarticles.html

you missed it!

Richard

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