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Anybody know anything about Solar Magic?

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Posted by Chuck Olson on January 29, 2009, 2:54 am
 
Solar Magic is a 4-terminal module made by National Semiconductor Inc.
that's supposed to "squeeze every bit of energy out of a solar panel even if
it's in the shade", according to a high official at National. Beyond that,
there seems to be total secrecy. This is highly unusual for National Semi,
noted for their total disclosure policy on all their ICs and Semiconductor
products for engineers to use in their designs.

Why all the secrecy? Why can't they present it honestly and in a forthright
manner - - and also maybe mention the price?



Posted by Calvin on January 29, 2009, 8:02 am
 
Chuck Olson wrote:

Most likely the technology is the subject of a patent application. Once
all the "T"s are crossed and all the "I"s are dotted on the paperwork,
they will probably be far more forthcoming.

Calvin.

Posted by Russ in San Diego on January 29, 2009, 3:30 pm
 
Sounds like a MPPT module to me.

Posted by Roderick on February 13, 2009, 12:02 am
 wrote:

I saw a video of it.  I'm not sure it's a big secret.

They had some golf-carts wired for a demonstration, and showed that
when the panels of the carts were PARTIALLY shaded (they had line
shadows falling on them), the "solar magic" array suffered much less
degradation.

This issue is well-known when many solar cells are wired in series to
make a module.  If you wire 100 cells in series, each producing (say)
0.5 volt at 4 amps, you will have an array that produces 50 volts at 4
amps - 200 watts.  But if just one cell is shaded (just the shadow of
your hand), that individual cell goes high impedance, blocking the
current.  Then you get very little out of the entire panel.

Modern panels generally incorprate bypass diodes, so if a small part
of the panel is shaded, the current goes around the dark cells, and
you still get reasonable power out of the panel.

Other approaches at dealing with shading at increasingly larger scales
are micro-inverters (like made by Enpahse), and independent Maximum
Power Point Tracking (some inverters track their strings of modules
separately).  Given National's experience with switching power
conversion, I'd say they probably are (or were) intending to market a
controller chip for a microinverter.

In most installations, this makes no difference at all, because
generally, panels are not installed where they will be even partially
shaded during the day.  Shadows fall on our panels only in the very
early morning, or an hour before sunset, times when there wouldn't be
much sunlight to harvest, anyway.

Posted by stevey on February 13, 2009, 4:51 pm
 
I like Roderick's comments.  NSC posted an article with links to a
recorded demo,
at: http://www.renewableenergyworld.com/rea/news/article/2009/02/shade-happ=
ens-54551
and www.national.com/analog/solarmagic.  The video demo did not say
what was the
configuration of the electric cart.  There is much potential for added
intelligence fo
solar panels, or array and I applaud National Semi for effort in this
area.  I can see
NSC going into 'Smart Panel' manufacturing, by integrating the
Solarmagic into a
solar panel, resulting in better value proposition.

Chief benefit I see from it will be reduced degradation due to shading
that is unavoidable
from objects on rooftop, or overgrown trees, and perhaps massive bird-
drops.  So for
many sub-optimal rooftops, it maybe more justified to to solar.

--solarMD


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