[Power] [support-gang] 3 portable solar choices for XO-1? (and other XOlaptops, if poss!)

Richard A. Smith richard at laptop.org
Thu Jan 16 13:06:24 EST 2014

On 01/15/2014 09:24 PM, Nathan C. Riddle wrote:

>> Yes they are larger than the GP panel but effectively the Auria solar
>> panel is a 10W panel rather than the rated value of 15W.  The thermal
>> de-rating for polySi in the Auria panel is much larger than aSi used
>> in GP.
> The 10W GPSP101402 (GPP0100C140V03) is 22" x 15 1/4" so 30" should be
> about right for 15W GPSP151400 (for same width)

The 15W is slightly wider than the 10W and just over 31" long (410x790 mm).

I've put the data sheet here:


> Auria 15W   SEC S/N:OLPC-C 20121012xxx  is 15.5" x 13"
> So GP 15W is about twice the area of the of the AS 15W (AS about 15%
> higher in cost)

Yes but the GP 15 is going to give you more output per unit cell 
temperature.  They aren't really a direct comparison.

> Uncertain about "much larger" thermal de-rating.  10%  ??

The Pmpp temp coefficient I have for Auria's module is -.55%/degC.  I 
don't seem to have an official number from GP but the typical I see 
listed for aSi is -.2%/degC.

At a NOC of 65 degC that derates to:

GP 15W: 13.8W
AS 15W:	11.7W

Jessica:  Since you are getting quotes from GP Solar on buying more 
panels perhaps you could request the Temp coeff for Pmpp.  Since you 
said that Richard Yu is no longer handling the account whoever the new 
person is won't have a clue who I am.  Potential customers get better 
service. :)

>> Real world peak numbers would be:
>> 10W GP:  7-8W
>> 15W GP:  13ish (A guess since I've not tested it)
> I note ratioing 15/10 gives 10.5-12W
>> 15W AS:     10W       ( Vmpp= ~ 16 volts)

The numbers I reported for 10W GP and 15W AS are the typical values I 
saw delivered into the battery of the XO-1.75 and XO-4 laptops.  They 
will be a bit lower than the panel output due to the chargers DC-DC 
converter.   Looks like my guess of 13W for the GP15W is in the right 
ballpark though.

Richard A. Smith  <richard at laptop.org>
Former One Laptop per Child

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