[RE-wrenches] Positive-ground question re Sunpower

[Mark Frye]

>From the 2006 white paper:
"Polarization

Incorrect grounding of SunPower modules can induce a surface charge which
would lower the energy production. Previously SunPower has announced the

discovery of the "surface polarization" effect which creates

a non-destructive and reversible accumulation of static

charge on the surface of high-efficiency solar cells such as

SunPower's A-300 cells [9]. When the cells have a high

positive voltage with respect to ground, a negative static

charge is built up on the surface of the cell due to current

leakage through the glass and the highly insulating front

surface anti-reflection coating of the cell. This negative

static charge causes increased surface recombination and

the performance of the module is reduced. If the polarity

is reversed and the cells are highly negative with respect

to ground, the negative static charge is replaced by a

positive static charge which restores the module

performance."


Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  

 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of jay peltz
Sent: Saturday, November 20, 2010 4:30 PM
To: Allan at positiveenergysolar.com; RE-wrenches
Subject: Re: [RE-wrenches] Positive-ground question re Sunpower


Hi Allan, 

I have seen the white paper from Sunpower, ( but don't have a copy) that
shows the losses as the voltage rises if using neg ground.

But from memory, if using at low voltages such as two in series there should
be minimal if any "loss" of watts.
If you could use them as singles, for say a 12v system then there is no
loss.

Jay

Peltz power
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