I like to snap energy monitoring sensors onto those ubiquitious loads that are found in any non-trivial enterprise. Over the past week, I have been looking at vending machines. In our previous offices I used to sit not far from a machine that served choclate bars and potato crisps (“chips” for our stateside friends). The noise level produced by its chiller often forced me to plug it out. Now why on earth do potato crisps need to be chilled???

Regardless, it got me thinking about the energy use of the humble vending machine – a machine that is often supplied “free of charge” to unsuspecting building owners and funded by sales of the product within. I surveyed two machines as follows over the space of a week.

Machine #1: this machine serves choclate mostly and seems to run pretty quite. Here are the stats for seven days:

• KWh: 18.55
• Energy Cost (at 16c per KWh): €2.96

  

  

  
  

Machine #2: this machine serves the Real Thing and it throbs loudly -always-! Here are the stats for seven days:

• KWh: 57.12
• Energy Cost (at 16c per KWh): €9.13

 

So, over a year these things cost €153.92 and €474.76 respectively (obviously your cost/KWh can vary). This seems quite steep – for the second especially. However, the question must be asked – do cans of Coca-Cola need to be chilled 24×7? Our building is occupied mostly during office hours. Surely this means that a simple timer could be used to switch off the machines (say) from 7pm right through to 9am (most folks don’t need a chilled Coke first thing in the morning). Assuming a good plug in timer costs €35, you could get a return on investment in less than two months. Thats not too bad, is it?

Yeah sure! Coke machines are small in the great scheme of things. However, we have found that simple little illustrations like this can help get employees more excited about the potential of reducing energy costs.