I am new around here, but I will weigh in with a couple of thoughts. I did own a vending company for 24yrs., sold it 3 yrs. ago and now am a consultant for smaller vending companies (when I am not blogging, lol)
First, you do not necessarily need a dedicated healthy snack machine to sell these type of products. You can request your vender at your workplace to carry some healthy products in their existing machines. The largest problem most vendors still face with healthy products is the increased cost factor that the average consumer is not willing to pay for. On average, 'junk food' will still far outsell any healthy snack, very sad but simply the facts. I hear clients all the time wanting more healthy snacks but certainly do not want their commission check from the machines to drop, or want their patrons to pay more.... a constant problem. I am in the MD/DC/VA area and in the past 3 or 4 yrs. the schools have been forced to stop selling 'junk' snacks and only provide healthy snacks. The schools had to be forced to by the local legislatures..... not because they do not like selling healthy snacks, but they were dependent on the commission income. For example, I had 2 high schools who received over $30,000 per school year in commissions but when switched to all healthy, dropped to $4,000 to $6,000. This was a much discussed issue on the local news, as local schools were desperate to replace the lost revenue.
Another point I would like to make is that all vending machines are becoming more energy efficient, which is great! With modern technology most new machines being sold can be programmed for peak usage. Also many locations such as schools, offices and manufacturing do not allow machines to be used at certain times, which was a factor in manufacturers improving the programming. Vendors normally do not pay for the electricity on locations, but for some refrigerated units such as soda machines, a benefit for the vendor is the increased longevity of the compressors - a major cost factor. With many refrigerated units, such as sandwich machines or ice cream machines, there are health code issues and the temperature must remain constant. Vendors do have options when they buy their machines as there are many manufactures just like automobiles. For example, Coca Cola buys most of their machines from Royal Vendors or Dixie Narco - a Maytag Company.
Again, I am new here so I hope nobody thinks I am being negative, just trying to enlighten to some facts. Going Green is a long and expensive conversion process, snacks and vending machines are just a small part. I do my part as much as possible, even have a going green website now!