Dude! Free power!

[unixronin]

In small quantities.

The Perpetua Power Puck is a solid-state thermoelectric power supply with no moving parts, that can run low-power electronic devices off of ambient thermal gradients as small as 1°-2° C.  The Power Puck weighs 60 grams and can supply regulated voltages from 1.5V to 3.3V.

Comments

[jhetley.livejournal.com]

I would expect output to be less than a photocell of similar size and less cost . . .