Hi, I'm new here, but do have a few years of experience in the electrical field, so hopefully my advice will help. While good in therory, it really wouldn't be cost effective to run heat lamps using solar power. They draw a lot of power and you would need a more expensive solar system to run it. Plus in the winter the sun isn't as strong so you'd need an even better system since it won't be able to run at peak performance. Now running a small 40watt, or less, is possible on an inexpensive solar system it may not meet your heating needs. You're right about the CFLs not really producing any heat and its the same for LEDs. Hope this helped. If you really wanted to get power out there for heat (and personally, from what little I do know about chickens, I think that over heating or shock would be a concern since a small coop would heat up rather quickly) its pretty easy to run power from an outside recepticle as long as it isn't too far from the power source.