# New portable solar charging mat



## Scotth (Jan 4, 2013)

> Almost a year after the U.S. government first certified Alta Devices as having created the highest efficiency solar panel in existence yet, the innovative California clean energy startup on Friday unveiled its first product: A flexible, extremely lightweight and fully portable solar charging mat designed for the U.S. military, which also achieves the highest efficiency of any such solar portable charging device used by the armed forces.
> 
> Alta Devices’ new solar charging mats (PDF) come in two sizes with differing energy outputs — 10-watt and 20-watt, both which offer world record energy efficiency of 24.1 percent, an increase even from when Alta was first certified by the U.S. government in February 2012.
> 
> ...


 
Remainder of story with video link and other technical links.
http://idealab.talkingpointsmemo.com/2013/01/alta-devices-military-solar-charger.php?ref=fpnewsfeed

Seems like a good item to have and only will get better down the road.


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## DA SWO (Jan 4, 2013)

Privately funded, Americans at their best.


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## Marauder06 (Jan 5, 2013)

SOWT said:


> Privately funded, Americans at their best.


 
Solyndra who?


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## Mentonin (Feb 8, 2013)

It's very easy to underestimate what these guys are doing.  There are definitely higher-efficiency solar cells on the lab bench, but what's impressive is that these guys are doing it with silicon.

Other "high efficiency" cells are typically made from thin-film materials, such as CdTe (Cadmium Telluride), CdSe (Cadmium Selenide), or CIGS (Copper Indium Gallium Selenide).  The physical properties of these materials makes it possible to make a solar cell "sandwich" with multiple layers of absorber material, and dramatically increased efficiency.  However, for this application, the drawbacks probably outweigh the advantages because 1) most thin-film materials are awfully toxic and (this is more important) 2) they are much more prone to degradation in the field.  In general, it's much harder to make a high-efficiency solar cell with silicon than with thin-films.

The Shockley-Quiesser efficiency limit mentioned in the article relates the theoretical efficiency of a solar cell to a physical property called its "bandgap", but there are other factors which lower the theoretical efficiency.  The fact that Alta Devices managed to get so close to the efficiency limit and successfully implemented a large-scale manufacturing process is quite impressive.


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## Coyote (Feb 9, 2013)

By the sounds of it you should have been one of the kids featured in the Bill Nye The Science Guy flicks.


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## The Hate Ape (Nov 5, 2013)

If it charges a tough book or some radios effectively its gold IMO. I'll still carry 5590s regardless...


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## devilbones (Apr 2, 2015)

Which battery operated items seem to lose their charge most often?  If there was a piece of gear that could use a better battery which would it be?


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## x SF med (Apr 2, 2015)

devilbones said:


> Which battery operated items seem to lose their charge most often?  If there was a piece of gear that could use a better battery which would it be?



Yes.


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## pardus (Apr 2, 2015)

devilbones said:


> Which battery operated items seem to lose their charge most often?  If there was a piece of gear that could use a better battery which would it be?



Radios/comms are probably the most important, electrically powered items in the Military.


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## Viper1 (Apr 2, 2015)

devilbones said:


> Which battery operated items seem to lose their charge most often?  If there was a piece of gear that could use a better battery which would it be?



As xSFmed and Pardus mentioned, every single battery operated item burns through batteries rapidly.  Comms is the biggest battery killer but anything battery operated is about the same.  Anytime we could use a power converter for a wall or vehicle hook up we did.  Batteries themselves are zapped quicker by heat and cold.  Just the nature of the beast.  Always have a good supply on hand.


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## AWP (Apr 2, 2015)

Even with a reliable means of recharging one's batteries you'll still take as many as you can carry. Batteries physically break, they have environmental issues as pointed out above, and one of the first steps in troubleshooting any electronic device is "power." Rechargable batteries will also develop a memory, so they require some care to be effective. Solar charging and battery architecture aren't in a place where you could rely on that marriage. Cool stuff that will one day mature, but that day isn't here.


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## x SF med (Apr 3, 2015)

BUT, there is always the XO's easy chair to fall back on.:wall:


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## CDG (Apr 7, 2015)

Freefalling said:


> Even with a reliable means of recharging one's batteries you'll still take as many as you can carry. Batteries physically break, they have environmental issues as pointed out above, and one of the first steps in troubleshooting any electronic device is "power." Rechargable batteries will also develop a memory, so they require some care to be effective. Solar charging and battery architecture aren't in a place where you could rely on that marriage. Cool stuff that will one day mature, but that day isn't here.



We had a company come out with a battery set-up designed to power all of our shit at once with a solar panel that went across the top of a ruck/pack that would re-charge them during movements.  Cool concept, but like you said, no one's gonna trust it enough to not pack a normal battery load out.  Add to that the eleventy billion extra cables that it came with and we said "no thanks".


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