Are you ready for this? You're gonna ask yourself "Now why didn't I try this before?" It's this simple, quit buying your chicks in the spring! That's it. Just start buying them a few months later then normal and you'll have eggs in winter. Let me explain.
Chickens start laying eggs when their body reaches maturity. Depending on the breed, its when they are about 4-6 months old. Most of us get chicks in spring. That puts their age of maturity around late summer, so that's when they start laying. They tend to lay regularly for about 4 months then shut down for winter. The shorter days trigger their bodies to stop laying and we get that 'break' in the production cycle. Spring rolls around and they start laying again. Even if your ladies are a few years old you'll still get more eggs in spring then the rest of the year. They slow down as they age and that's completely normal. The 1 year and 2 year old hens though, will be kicking out eggs like crazy in spring and through to the end of summer. This is why you want to buy your chicks later in the season, so they're growing during this already high production time and then start laying when everyone else stops.
I noticed this 3 years ago and have been keeping data ever since. Now that I've started yet another season of winter egg laying, I'm thinking I can call this method a success. Here's generally what happens. Around November or early December the newest batch of pullets start laying. They lay eggs through winter till about February when they start to slow down. They keep this slowed down pace till spring, sometimes even stopping for a few weeks. Around late spring they start laying daily again keeping at it till late summer/early fall when they go through their first molt. The slowdown in the early spring coincides with the older hens starting up their laying cycles for the new season. See? Eggs year round!
I like this method far better then any other I've heard of. It still keeps with the chickens natural need for a 'break' in egg production. It doesn't spike your electric bill like supplemental coop lighting. It's not unnatural for chicks to hatch year round (not as common, but not unnatural). So this is a normal production cycle for a chick hatched in late summer. By staggering them into your regular flock, you get the benefit of year round eggs without messing with their natural body rhythms. Plus, you can get some amazing deals on chicks since you're not buying at the high demand times. I'd say this is a win-win for all of us!