What determines the amount of energy an appliance like a refrigerator, consume? Is it the Wattage?

Yes, wattage.

I guess those tiny fridges are exempt from the usual energy tags that major appliances are required to have. It’s difficult to know which fridge would consume the least energy without actually testing it in real world circumstances, but on the back of every appliance there is a little label (often near the power cord) that says something like this: 120 volts AC 60hz 2 amps. It’s that last number that shows what the appliance’s peak power consumption is. Therefore, a 2 amps appliance uses less power than a 2.5 amp appliance.

To confuse matters, though, this doesn’t mean the appliance is always drawing that much energy. And also sometimes the power consumption is listed as watts. But to compare watts to amps, do this equation: amps times voltage = watts. Therefore 1 amp times 120 volts equals 120 watts.

Hope this helps!