Right, i have done this, and its next to me now.

Do not run it off the mains, and i mean that!

Gets a 9 volt batter, and wire it up, 6 volt will also work.

It's PERFECT for small seedlings, but wont last the WHOLE grow.

IT's a good idea, so i rekon you should go for it, but it has to be taken outta the PS2, and wired up with batterys.