A while back I had found a bunch of little solar cells on Ebay for cheap. I hadn’t really looked at them or tested them in any real way but today I wanted to see if they could power even a small project. As it turns out, I would require a great number of them in order to make even an LED light up (Assuming no capacitor or storage device). Since the sun was going down, I needed a constant source of light so I used my desk lamp. Here are the comparisons.
Those are the units I bought. I think I got like 30 for $10 or something. relatively cheap, but not really. I was expecting some decent performance, which I got, but not nearly as much as I expected.
This is the competitor. It’s the old Archer 6-12V solar cell pack. It’s quite old (25 years), the lens is dirty but it still works quite well.
And here is the test cell/array that I soldered together.
Now, keep in mind that this was all done with a desk lamp. I maintained a certain distance from the bulb and only used the maximum measurement received by moving the panel around. Also given are comparitive measurements for the overall visible area exposed to light.
|Old Archer Panel||Cheapy EBay panel|
|Measured Amperage||305 uA||628 uA|
|Calculated Watts||1.6 mW||.1 mW|
|Measured Area||14.05 Sq.in.||1.6524 Sq.in.|
|Cell Sizes||.788in x .563in||1.063in x .433in|
|mW per Sq.in.||.113mW per sq.in||.06 mW per sq.in|
That all being said,you could still run quite a few little things at that low current rating if you were to link together all of the cells for whatever reason. unfortunately, nothing that I want to do could use them. So the lesson for the day is “Quality over Quantity”
Also, as an aside, here’s my new Agilent U1271A multimeter. Works like a dream!!!
Perhaps tomorrow or someday I’ll give figures for sunlit voltages/amperages.