The Peltier effect IS the thermocouple effect, which is also the Seebeck effect.
http://en.wikipedia.org/wiki/Peltier-Seebeck_effect

Thermoelectric power generation is woefully inefficient. Most of the heat just passes right through without being converted to electrical power. However, sometimes it is appropriate.

Devices similar to the one shown have been around since WWII, IIRC. They haven't improved very much, despite a ton of research that was done in the 50's/60's in search of the holy grail, a more efficient material that would allow it to be used for large scale applications like nuclear subs.

How do I know all this? I used to work for a Peltier module manufacturer.