If you are going to bother with a panel avoid that type like plague. (Please take no offense
) Short lived and fragile- those are referred to as "thin film" technology, or "amorphous silicon" panels.
You want polycrystalline or monocrystalline. And used (!!!) is almost always fine for these types they live for many decades with minimal degradation. If you aren't too picky, they are often given away FREE when damaged during removal, and most use safety glass, so they often still function, but with a slight drop in performance from the refraction of light along the cracks. I got a pile of unbroken 150w monocrystalline (best type) for $35 each from an industrial roof tear-off.
As long as what you are trying to do has minimal power requirements and you can live with running DC only, all you need is the battery, a charge controller, and a panel.
The charge controller in my other thread IIRC is about $20 (
Ebay) and I have had good luck with them. Stone age simple to wire up. Heat is a challenge to make from solar though. It's very easy to use a LOT of juice making heat. AC heat elements work fine if you don't mind doing a little math. I am running 240v water heater elements as dump loads for my non-chicken solar/wind system. But lower voltage means lower current passes through the element. Making light is a different story- LED's are about as efficient as fluorescent, and are particularly suited to low DC voltages.
In "theory" you can use a matched panel without a controller, but in reality it sucks pretty badly to do so. This arrangement "regulates" by having a panel that only makes max voltage nothing more. Which means your lower voltage production periods do NOTHING, and now and then the voltage *will* spike and overcharge the battery despite the theory.
MPPT (Maximum Power Point Tracking) controllers are best, but a PWM (Pulse Width Modulated) is probably fine for a coop. They both allow a higher voltage panel so that you get production almost all of the time there's light, and won't overcharge the battery boiling away the electrolyte. Watch that you stay within "open voltage" specs on the controller when planning though.
PS:
One last detail- I specifically chose a dedicated solar even though both grid and Alt-e nearby. Not only is there no extension cord running across the yard (obvious safety hazard) but the charge quality of even the cheapo charge controllers *far* surpass even most of the best shop battery chargers. Most wall chargers are either unregulated or surprisingly wasteful.
A major deciding factor for me is that I have run various rarely used 12v winch and electric over hydraulic systems in my shop, and one of two things happens: I either forget to charge them and ruin the battery, or put them on a "float charger" that very slowly boils away the electrolyte until the battery explodes. I have even had this problem with sealed AGM batteries. The solar CC's just seem to work. I finally decided to keep *one* battery on a small solar system and just swap it in as needed.
