Ahh, thermo-electrics...I first became familiar with the technology when it was restricted to military/NASA use. Thermo-electrics hold great potential for efficient heat exchange, but unfortunately, it is only really practical when the temperature difference is large. I.E. Thermo-electrics are great at changing a volume from 80c to 10c, but lose efficiency when it comes to maintaining temperatures. The less the difference between the target volume and the outside temperature, the less efficient it becomes. The great benefit from thermo-electrics is that the coolant system requires no moving parts other than fans that circulate the air. Thermo-electric systems often cost more than standard refrigerators, even though they are more efficient over time. You will lose a bit of heat in the python, so you may want the coolant to be a bit colder. What you do not want is an 'open system'. If your head pressure in your kegs does not overcome friction and gravity with a positive value, than you are losing carbonation as you pour. If you only pour 1 glass at a time, with a reasonable time between pours to build up pressure, than everything will be fine, if not you will lose carbonation on the total volume, and with each beer poured, the foaming will get worse. BTW, the cool thing about thermo-electrics is that if things are reversed...Heat on 1 side and cool on the other...electricity is generated.