So, just planning ahead for meat chicken slaughter day. Not until mid-June, but OCD needs to be scratched. I'll need ice for that day. A lot of ice. Like 400lbs just to get started. Probably will go through 600-800lbs that day. Mostly for an ice water bath to quick chill the carcasses. We're getting 100 broilers and plan to use a 140gal stock tank for the chilling. Figure on using 100gal of that capacity, and wanting 50% ice means 50gal ice, times 8lb/gal is 400lbs. Additional ice to recharge the chill tank throughout the day, and provide some for helpers taking chickens home in a cooler.
My question is if my calculations on the cost of making said ice is correct. Based on the specific heat of water, heat of fusion, and specific heat of ice I've calculated 414KJ/kg to go from 50F (10C) to 0F (-18C). That works out to 0.115kWhr/kg. I'm assuming 10% effeciency between the deep freezer's effeciency and any losses in transferring heat from the water to the refrigerant. So 1.15kWhr/kg. At local rates of around $0.11/kWhr that's $0.1265/kg or about 6cents per pound.
Does that seem reasonably close? Trying to figure out if it's cheaper to make my own ice or buy it.