I thought about this, and read about it a little bit, because food sufficiency is kind of antithetical to large electrical freezers. Here are my thoughts.
You get some decline in meat quality as the birds hit puberty. Plus the boys start fighting. Whether you can tolerate that depends on your priorities/facilities. If you learn to caponize (neuter), then the boys can be held much longer, remain tender and behave better. Other than that, you can start a batch, butcher at twelve weeks (this is underweight and less profitable, but not everybody is running a store), and more at say sixteen weeks, and then a few that would be tougher at twenty weeks. Then if you are skillful/lucky, your younger chickens reach twelve weeks the next month, and so on. You would have to heat the scalding water, cool the chill water, and clean your equipment for each butchering, so it saves time/energy to do more at once, say every four weeks, and freeze, than to do one a week for example. This alone makes the energy usage of the freezer more palatable.
So if a litter or brood (I don't even know the word! lol!) averages fifteen chicks (??) and you butcher at 12/16/20 weeks, you would butcher about five chickens each time, and have meat for three months. So you likely could repeat this twice a year and have meat for six months. The next issue is that whole lack of light means December is a bad month for eggs. So if you could get them broody in Oct, and growing Nov Dec Jan, then butcher that bunch in Jan, Feb and March; then the next batch would be broody in Feb, growing March April May, and butchered May June July. I don't know how hard it is to get a hatch going early/late season like that. You would likely have some gap in the spring, but your mileage may vary.
Most people seem to find it easier/more fun to raise chickens in the summer and freeze the meat, rather than trying to manage winter poo for larger batches of chickens semi-indoors. A spring break just makes sense all around. A partial solution is to butcher lamb in the spring, at 10-11 months old. Or barter. I suppose our forefathers shot deer. Maybe turkeys work better to butcher in spring. Palm turkeys could be 30 weeks to butcher, says the Internet. That might work out better than keeping baby chicks going all winter. So my conclusion there was that if we want fresh meat every week, some seasons do not favor chicken.
Then again I don't even have chickens yet, so don't listen to me. just dreaming about someday.
