Off Grid Home Forums Technical Discussion Solar panel effectiveness Re: Solar panel effectiveness


My first system was limited by roof size and orientation of the original house. A shell I finished, all trades. The only way we could afford another house with wages suppressed for 20 years by the invasion.

I calculated the need for 11 -75W panels without tracking. So I bought a Wattsun and used 8 panels for the same power. Maintenance was done under warranty once, and I bought a $200 manual control because the sun seeker would pancake the array at times of hail or heavy snow.

When I expanded the house I found that using Unisolar amorphous film panels at just the latitude angle, fixed with simple 1×1 aluminum Ls and bolts gave around 90% of the power per watt as the full tracking array. Plus were unbreakable.

So with the additions we increased our power 60% for 30% more money, roof mounted. Remember, all do it yourself, too.

Now there are more textured front unbreakable thin film panels available. When I had to fix my glass array at the same angle as the Unisolars to send in the sun seeker for repair, the reflectivity of the glass with the sun at a 45* angle to the panels gave only 10% power, while with the Unisolars it gave 90% power. So for beginners and less expense, I would certainly recommend the textured surface unbreakable amorphous film type panels over the smooth glass panels. At least for 39* latitude or so, or less.

Of course, at the extreme north it still is a good idea to track for best performance.