[Power] Haiti power questions

[scott at solarnetone.org]

Hi Tony,


On Sun, 5 Dec 2010, forster at ozonline.com.au wrote:

> Full charge for XO1 measured at 156 minutes at 7.75 amps DC, but the voltage was a bit low

So that gives us, @12V, 93Wh per XO delivered over a period of 2.6h, or
35.77Wh per XO per hour, to achieve a full charge on the XO.
Our total load of 50 XO's for 2.6h is 4650 Wh. 
We must deliver 1788.5Wh per hour for the 2.6h charging period, assuming 
all 50 XO's a) started in a completely discharged state and b) 
were connected and charging simultaneously.  The latter is tough on your 
batteries.  If the school day is 6 hours, and two "shifts" of student 
charging can be accomplished, then the LA batteries will last MUCH longer, 
and our wiring can get much smaller.

According to the wunderground.com solar calculator:
http://www.wunderground.com/calculators/solar.html

a hypothetical deployment of 1.4kW of solar panels in Matelgate, Haiti
would produce an annual average of 7.3kWh generated per day, with a 
december minimum of 6.44kWh/day being collected. Similarly, 
1400Ah of battery will provide 3 days of backup.  I would consider these 
to be bare minimums for a system of this scale.

Apart from the panels, other components include combiner boxes, where each 
panel is individually breakered, a few charge controllers in parallel, a 
main breaker enclosure with busbars, breakers, lightning suppression, etc, 
batteries of course, all the cabling and interconnects, and some output 
bus bars with terminations that the XO's can be connected to.

Cheers,
Scott

>
> Done with an XO1.5 running Turtle Art
> http://wiki.sugarlabs.org/go/Activities/TurtleArt/Using_Turtle_Art_Sensors#Measuring_DC_Amps
>
> Tony
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