Soda machines use a lot of energy...

Soda machines are like refrigerators in that they are constructed to refrigerate sodas for our drinking pleasure. The refrigerator part of the vending machine uses a compressor that turns on periodically to keep the temperature low. Many of the 31 soda machines on our campus run 24 hours a day providing ice-cold soda for no one in particular at midnight, or 2am, or 4am. This is obviously not needed and amounts to a big waste of electricity and our money. The following is a graph showing energy consumption of a single Pepsi vending machine.


Using an experimental monitoring system that enables appliances to be turned off remotely or by timer, I have programmed the soda machine to turn off at 8pm and turn off at 6am. A rough calculation for the 31 soda machines on campus shows that turning the machines off at 8pm and back on at 6am results in using $18,000 less than keeping them all on all the time. In other words, we would need to sell about 36,000 cans of soda to pay to keep them cold in the middle of the night!