solar re-charger question

BikieB · #1 (**permalink**) 26th-November-2007, 06:17 AM

hi there!

i recently invested in one of those small solar cells (with battery) for charging mobile phones, ipods, etc. i've been exceedingloy happy with it, especially because (unlike my previous charger) i can leave it in the sun for the day and then charge items at night.

BUT i was told the other day that the amount of energy needed to make these appliances outweighs the amount of energgy they'll convert fro sunlight to electricity in their lifetime. does anyone know if that's true? or a good place to find out?

cheers!

LMagic007 · #2 (**permalink**) 26th-November-2007, 08:06 AM

I'm not sure about that. I think it would depend on each case in question. The useful life of the equipment and its power output relative to the power used in its full life cycle manufacture and including disposal and or recycling may need to be factored into the equation. You would then need to compare that to alternatives.

Still a handy tool for camping if nothing else.

Wobs · #3 (**permalink**) 26th-November-2007, 02:47 PM

One of the variables as to determining the energy cost in comparison to the energy produced by PV is the angle it is set to the sun. A wrongly set panel will have a lower ratio of energy return than a panel set at 90deg to the sun.

Further info here:
http://www.solarbus.org/documents/pvpayback.pdf

It is thought that one of the reasons this idea is circulated about more energy than it produces comes about is from NASA satellites. They don't have to worry about such matters, as performance is more important in such environments. But for Earth bound panels, its a different story.

There is of course a carbon cost with every energy source, and PV doesn't come out on top, but that doesn't mean it should be avoided. It does have many applications where wind or any other renewable would be inappropriate.

AlienFarmer · #4 (**permalink**) 30th-November-2007, 09:36 AM

I have also heard this about smaller solar panel chargers. I would think if you buy a quality charger that lasts for 10+ years and is used a lot it would produce more energy than it took to make. Of course something thats cheap and breaks right away is of no environmental use, but solar panels generally have a long life. Hope your charger lives long and you enjoy it!