A Short Description of Our Solar Home
Here is a winter shot of our home that shows the installation of the 6 Solec 100 watt PV panels on the roof. You'll notice also that the house has 3 main walls that face SE, S and SW. This allows for the maximum exposure to winter sun and provides almost all of our daytime heat on all but the coldest, windiest days. Even then, it takes very little additional heat, provided by our backup woodstove, to get the house warm. As long as the sun is out the stove need only be fired up for an hour or so in the morning.
The dark brown stain on the house was done intentionally to increase the heat absorption of the 8" logs. This lets the logs act as a thermal mass and help keep the house warm. The stain, called UVGuard, is produced by the Weatherall corporation. It is a water based stain that is incredibly easy to apply, very benign and long lasting. This photo of the house shows the stain after 4 years exposure to direct sun.
The rear of the house is bermed into the hill, with only about 6 feet of the wall on the second floor level above ground. This provides us tremendous protection against the cold north winds and helps hold the sun's heat in the house. Because the house is so well oriented to the sun and so well protected from the weather it will never freeze inside, even if we were to leave it unattended for a few days. Of course, we seldom leave it for even a day in the winter because it is such a joy to be here.
This is a closeup of the 6 Solec 100 PV panels I have mounted on the roof. Notice that the front of the mount is raised 18" above the roof level. This allows the snow which slides off the panels to collect below the level of the panels and not shade the lowest panels on the mount. This reduces the amount of time I have to spend on the roof cleaning off the panels (not a fun job) and increases their power output.
If I were to do this over again I would mount these panels on a ground mount like the one for the 8 BP-75 panels I have installed at the rear of the house. The primary reasons for this are to make the panels easier and safer to adjust for the seasonal sun angle and to make them easier to clean. There is also a National Electric Code requirement now (wholly unjustified, in my view) that any panels mounted on the roof must have a Ground Fault Circuit Interrupt device installed at the point where the output wire from the panels enters the roof. These devices are only now coming to market (they didn't exist when I installed my panels) and are expensive.
Mounting the panels on a ground mount, either a pole or frame mounting device, will probably be cheaper and certainly safer. It is never entirely safe to have to be up on a roof. Maintenance, cleaning and seasonal adjusting is far easier and safer from the ground than from any roof installation.
I was initially nervous about it consuming a lot of wood to keep it from freezing in our cold mountain climate (where below zero temps are common) but it has performed beautifully. We can let it sit for a week without use and not worry about it at all. Even a layer of ice a few inches thick has no effect on the tub.
Instead of filters, chemicals and pumps we use it like a Japanese tub, draining it and refilling it based on usage. We can go a month without having to refill it if we only use it occasionally.