There are some LEDs (light emitting diodes) that produces about 1.5VDC when you expose them to sunlight. I know the current rating of them is very small. I have never tested the current rating of them by shorting the leads i only tested how much voltage i get from them when they are exposed to light. I am assuming that the current rating is in the micro amp reading.
I am wondering if there are any available with current rating in the milli-amp/amp stage when you shorts it?
Because i am thinking that you could wire some in series to get say 18VDC then connect lots of the series strings in parallel to increase the current rating and then you would have a nice little panel at a really affordable price.
What is your comment on this?

 

The voltage isn't as high as you'd expect. The current is in the micro-amp range.

The oldest solar cells are still better than an LED array.

LEDs are basically good in detecting light of their own wavelength, and not the ideal device for that.

 

They make good photo-detectors, sensors in other words. Not too hot for harvesting energy.

 

It might not surprise you but solar panels are basically based on the same technology as LEDs and photodiodes but they are much more refined to produce a lot of output current and reduce certain other characteristics like response speed which aren't critical for most energy harvesting applications.

 

Compare the huge size of a solar panel to the tiny chip inside an LED then you will understand why the current from an LED is almost nothing when it is exposed to light.

 

Forrest Mimms III had some interesting ideas for light wave communication using LEDs as both receivers and transmitters. He was pretty much ahead of his time.