Thanks for all the comments and information. Please keep in mind that the light you are considering, is on all night and that research shows that chickens still need 6-8 hours of darkness for a healthy immune system. For our young flock of about 100 birds, I'm using two LED lights in our mobile 400 square foot coop. They are run with a long extension cord.
Soon, however, we are moving our coop to a paddock without power. I experimented with ordering some 12 V Christmas lights, but I don't think they are bright enough and they are harder to connect to our basic solar setup that includes a 50 watt panel, a simple charge controller ($10,
amazon), 12 volt LCD timer (also from
Amazon), and the lights. Since our mobile coop is about 20x22 feet, I decided to go with the more expensive 1 watt 12 volt lights so they can be placed in all the roosting areas of our coop. I solicited advice from numerous farmers about the light needs of layers and the best advice I found was about 60 watts equivalent incandescent for each 200 sq foot. This is how I arrived at purchasing 12 lights, a total of 120 watt equivalent.
In December in Montana, we need about 4 hours of extra light to get to the required 14 hours of daylight, so that means, after all the math and a good deep cycle battery, our 50 watt solar panel, purchased for $80, is more than enough for our needs. I should say that the entire system is 12 volts; we don't need an inverter.
I researched LED lights substantially, and I have purchased these:
https://www.amazon.com/1-5-inch-Lig...811&sr=8-4&keywords=12+volt+led+lights+1+watt
I went with this model since it's easy to work with the simple wires and I can change the arrangement. Since there is 2x4 metal to protect the chickens from breaking into insulation about the rafters in our mobile barn, there are multiple mounting possibilities. I will probably hang them and clip the wires directly to our metal wire.
I hope this helps. I'll be wiring up our lights and solar panel this week. With the insulation in the mobile coop, and the deep bending, are coop temperatures are about 12-20 degrees warmer than the outside temperature. This is with gable vents (open all the time) and an automatic door that's open during daylight hours. With this setup, we hope to only have to string extension cords to the mobile barn for a few weeks a year for the 100 watt (also on a thermo-controller) water deicer. This is how we do it now, but I'm always looking at ways to improve and simply our system as we scale our laying flock to about 200 hens.
In my research, I did find a nice LCD 12 volt timer available in the UK, but it was expensive and it didn't have the flexibility we wanted. I'd love to have a timer that just made sure we had 14 hours of daylight inside the mobile barn all the time, but I haven't been able to find one. At some point, I may consider upgrading our system, since at 200 layers, we can justify some continued infrastructure investments and improvements. If anyone makes a timer, or has a solution for this challenge, I'd love to hear about it.
Happy winter,
Noah