You are referring to thin-film amorphous solar panels. Many companies make them, some of the most affordable are made by Unisolar. The DOW units are self-contained and can be attached to a
wood sheathed roof, whereas the less expensive Unisolar panels are designed to be attached to steel roofing. Peel and stick. You can actually get them pretty cheap on Amazon and eBay, about $1 per watt. The
energy density is lower than polycrystalline panels (for two reasons), but the beauty is that you can't even really see them once they are installed.
The two reasons that you need more square-footage of panels than using standard panels are: 1) Thin film photovoltaics are less efficient, and 2) These panels run HOT because they are attached directly to a steel (or wood) roof. In both cases the DOW panels are the same, but I have also seen people run serpentine solar collectors on the UNDERSIDE of steel roofing systems to both collect heat for heating
water AND for keeping the panels at an acceptable temperature.
For the price, though, I would stay away from DOW. You could re-roof your house with steel AND buy the Unisolar panels for less than the price of the DOW panels alone, assuming you are going for grid-parity.
They certainly CAN be used off-grid. Any panel can with the right inverter. The economics of the situation becomes tenuous, though. If you are off-grid you are probably using far LESS power than a grid-tied home, and when you don't need a LOT of power, the thin-film panels are more expensive than they are worth. If you only need a couple kWh per day, you can probably just install standard panels on a pole-mounted system in your
yard, and not even worry about messing with your roof.
On the other hand, if you are BUILDING an off-grid house, like an Earthship, etc., Unisolar panels on a steel roof make for a nice neat installation, especially if you design heat collection into the roof as well, and steel roofing is probably the best material to use if you are collecting rainwater for potable.
