Not sure if this is in the most appropriate place so please feel free to relocate my post if there is a better sub-forum.
I am looking into the feasibility of doing a pastured poultry broiler operation on an off-grid property here in the beautiful subtropics of Hawaii. The property we're looking at currently has a small solar system which I'm guessing would need to be upgraded substantially in order to produce enough ice to cool down the meat after processing, and to keep it cool while transporting it to market. I'm thinking that we would probably need to use several coolers quite full of ice to progressively cool the carcasses off and then several coolers, say, half-full of ice, to transport them in. While I've been looking into the ISAAC
(Intermittent Solar Ammonia-water Absorption Cycle) ice-makers, I'm afraid the $7000 price tag is prohibitive and alas I don't yet
have the chemistry knowledge or the engineering skills to do it myself...
So, my question is: what would be the most energy efficient means of producing the necessary ice - a chest freezer or a purpose built ice maker? (or can you think of a climate-appropriate, outside-the-(ice)box solution to my conundrum?
I've noticed that most ice makers are rated according to how much ice they can produce in a 24-hour period. Obviously, if our electricity is produced by photovoltaics we would probably want to produce most of our ice while the sun is shining in order to avoid drawing down our batteries excessively. So, I'm guessing this would mean that an entry-level commercial ice maker that produces 100 lbs of ice in a 24 hour period would really only yield somewhat less than 1/2 of that figure the way we would want to use it. Then too, I'm not sure how to compare the energy consumption of an ice-maker with that of a chest freezer, since presumably the chest freezer works harder to make things frozen and then not so hard to keep them frozen, so that their energy consumption specs probably don't reflect the type of use we would subject it to on days when we needed a lot of ice all at once to process 100+ birds at a time.
I also came across a tip for making ice-packs for coolers that recommended using reusable bottles and dissolving a few spoonfuls of salt per bottle of water to be frozen, as this apparently reduces the time needed to freeze the water and also makes the ice last longer before it melts. Obviously it wouldn't be possible to utilize this energy-saving strategy when using an ice cube maker, but I'm also wondering if the ice makers aren't more energy efficient in the first place such that these gains would be irrelevant.
Does anyone have any experience or the knowledge necessary to teach me how to make an educated choice?