This is about the photoelectric effect, the current wikipedia page was reworded and now omits the tesla reference.

i do not feel like quoting it all so i will refer you to this page:
http://www.ionizationx.com/index.php/topic,913.msg17972.html#msg17972
specifically first and second posts.

i propose that if you have some spare roof iron that you make yourself a roof (design it to lower coronas), and isolate it from the ground and its supports by using glass insulators and then connect it to a circuit ie, a motor as shown in tesla's diagram and the sun will do the rest.  you can possibly build it on top of your existing roof (as an 'environmental' roof which casts shade on your roof so your house is cooler).

if you are stuck for ground area you can probably add semiconductor cells on top too but if a bird or anything lands on it when the roof is charged, static electricity would travel to the bird through the semiconductor and destroy the semiconductor, then is the problem of using the sola without discharging the roof... so dont do that.

and no, i havnt done it. live at parents house - cant modify it or untidy it, and other devices on here catch my interest. but good idea though...

Charlie.

attached is zip incase link goes down (i hate broken links)