Electricity, water, bags, labor and a mop
Eis ist die teuerste Art, kalt zu sein
The machine, the water it drinks, the bags you buy when it runs out, and the person who hauls, spreads, drains and mops. Cost it per service.
Industry figures put commercial ice production between roughly 4.5 and 12 kWh per hundred pounds depending on the machine's age, plus potable water and, for water-cooled units, another hundred-plus gallons of cooling water per hundred pounds. The U.S. Department of Energy scores machines on both.
Then the rest
Bagged ice when the machine cannot keep up. A person to carry it, crush it, spread it, top it up and drain the pan. Floor drying where it drips. A slip risk for the whole service.
Per service
Add the ice, the water, the electricity, and an hour of labor, for every cold display, every day. Then compare with a cell that is frozen overnight in a freezer already running, holds −10 °C for eight hours, and is put back.
The crossover
For a daily cold display, a set of cells pays for itself within the year on labor alone.