Re: [Vo]:70% solar panels

[Stephen A. Lawrence]

Brian Prothro wrote:
Regarding the incredible sounding 70% efficient solar panels mentioned on
this board last week.  

A powerpoint brochure was released by Nelson Mensch of FreEnergy
Environmental Solutions, LLC.  However, he is actually only a “Dealer” for
the company DBK Corporation at www.dbksolar.com  FreEnergy’s brochure hints
at secret technology, probably to prolong their edge in penetrating their
market as a dealer.  A press release at the end of 2007 somewhat implies
FreEnergy are uniquely associated with the inventor, and makes it sound
solely between Andre Woods and Nelson Mensch.

Now to the good technical stuff at DBK’s website… 

The specification includes the embedded or attached “dc-dc inverter which is
physically part of the panel”. 

JIL-3000
Rated Power (Watts)     3000
Series Fusing (Amps)    15
Current at Max Power (Amps) 14
Voltage at Max. Power (DC Volts) 220
Short Circuit Current (Amps) 14.8
Length (Inches) 62.5
Width  32.5
Depth of Frame (inches)  3.5
Shipping Weight (lbs)  70

It seems they are about to produce a smaller 1500 watt panel as well.

An enlarged picture from the website shows a meter reading the 62.5” x 32.5”
panel in full sunlight showing 2.8 KW on the meter.
http://www.dbksolar.com/JIL-3000.htm  Note that normal panels this size
produce about 200 watts - impressive.

That is a bizarre picture.  You will need to look at exactly where the 
wires are going to see what I mean.

There is a very heavy duty pair of cables coming out of the panel, which 
terminate in big battery-clamp style alligator clips.  OK, a little 
strange for the cables you'll use to connect up a panel with, some kind 
of screw terminal might seem more appropriate, but they look able to 
carry the load anyway.

But look at how the power meter is connected.  A power meter needs to 
sample voltage /and/ current.  So, the voltage probes are connected to 
the giant alligator clips; very well, that will give it the voltage 
reading.  And the current-sensing loop is hooked around the red cable. 
That's a little odd, when you think about it, since the panel might be 
expected to produce DC which wouldn't do much for the current sensor on 
a power meter, but never mind; perhaps this panel has an inverter built 
into it and is producing AC.  Whatever, the current sensor is on the red 
cable, and the voltage sensor is across the ends of the red and black 
cables.

Now, the meter says 2.8 ... uh, kW, apparently, can't read the fine 
print in the dial well enough to be sure of the range.

But ... WHERE'S THE LOAD???  The *ONLY* thing connected to those moby 
alligator clips is the power meter.  It appears that the POWER METER 
ITSELF must be dissipating 2.8 kW.

There should be a cloud of smoke squirting out of the meter.

Actually, there shouldn't, as the impedance of the voltage sensor is 
presumably very high, so the current through the meter can be assumed to 
be very small.  But then, with nothing but a power meter for a load, 
it's impossible for the panel -- or anything else -- to be pumping 2.8 
kW down those cables.

Note that whatever is in the box containing the solar panel makes no 
difference to this observation.  The point is that the only thing 
connected to the ends of the cables is the meter, so any current flowing 
through those cables *must* be going through the power meter, and the 
voltage being read is the voltage being fed to the power meter.  So, the 
meter *is* the load -- and that doesn't make sense.

The piece that's missing is a big honking resistor with a huge heat sink 
acting as a test load, maybe with the whole thing in a bucket of water 
to keep the insulation from melting.  But it's not there, and there's 
nothing connected to those cables that could take its place.