If you have the space, you can get a couple of 55 gallon drums, paint them black, get a pump and rig up a system to allow the water to flow from one barrel to the other using pvc pipe painted black. The barrels will act as heaters during the night, discharging their stored heat acquired from the day's sunlight that heating everything black. The pump can be run on a couple of deep cycle batteries & a solar panel, or two. Most people run their piping above, facing south so it gets sun all day. Digging your floor down three or four feet will also help keep things warmer at night. There's a lot of tricks when you live in such a hospitable climate. Solar panel kits can be bought on eBay & assembled for a fraction of retail cost. I found a Chinese supplier of vacuum bags for making commercial quality panels; the material used to encapsulate cells is cheaper in rolls than a liquid polymer resin. Panels can be assembled, placed in the vacuum bag, heated in a homemade over while pulling vacuum, then voila, a panel that'll last 20+ years. It'd be less expensive if you got a group of DIY people that want to make solar power for a fraction of retail. In these unstable times, I imagine women soldering cells instead of knitting in a rocking chair.