My father put a thermal electric cooler in his boat several years ago. He ended up never using it because it sucked Amps so bad and really didn't cool the ice box enough. I use one in the car where Amps are plentiful but I would caution you to measure power usage before cutting up anything. From Wikipedia:

"Thermoelectric junctions are generally only around 5–10% as efficient as the ideal refrigerator (Carnot cycle), compared with 40–60% achieved by conventional compression cycle systems (reverse Rankine systems using compression/expansion)."