But bales of straw might still be an option. I don't really need straw for anything other than insulation, though, so is there a good use for it in the spring/summer?
Put it in the run. Then if/when it starts to get Nasty, compost it and use it for the garden
BTW I am skeptical whether you're going to be able to get away without *any* electric heating -- but the more you insulate, the fewer days you will have to heat and the less wattage you will need, so it will still save you money
If I set the timer for the light to turn off, can the chickens then find their way to the roost when it suddenly goes pitch black?? I picture them out there flapping and stumbling around or just sitting down on the floor in defeat.
There have been some Heated Debates about this in past threads. What you describe is in fact what normally happens -- however, enough people set their lights to turn off suddenly and report that after a while the chickens learn to get onto the roost *before* lights out (in anticipation) that I am willing to believe it happens. Basically your choices are something like these:
1) put all of your added light in the morning, even if that means lights come on at 2 a.m., then turn off after sunrise (or, I forget what latitude the arctic circle is, *do* you even *have* sun on every day?) so the chickens experience natural dusk. This has the advantage of adding heat (from light) to the coop when temps are coldest.
2) put some or all of your timered light in the evening, and wait for them to learn to deal with it.
3) put some or all of your timered light in the evening, but add a second much-dimmer bulb on its own timer to go off 30 min later. (much more complexity is a downside)
4) put some or all of your timered light in the evening, but leave a dim 'night light' on 24/7 so it is never pitch dark in the coop.
5) run a red lamp for heat all night anyhow, which kind of renders the rest of the question moot (and if it is bright enough, may be sufficient for egglaying stimulation too)
I have also seen a lightbulb (plain ol 60w type) for sale, a bit expensively, that claims to dim itself slowly on its own for, I forget, 30-60 min after being turned off. Designed for use in bedrooms. I have wondered sometimes about its applicability to this situation in a coop but have not tried it.
Good luck (brrrr!), have fun,
Pat