Author Topic: Solar power issues?  (Read 2599 times)

Offline Grasshopper2Ant

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Solar power issues?
« on: March 02, 2009, 08:38:49 AM »
I mentioned solar power to my husband this weekend and he said that he had heard of problems with solar cells on your roof.  Basically, they expand and contract with temperature changes and eventually the seals fail and they cause your roof to leak.  Has anyone heard anything about that?

MightyRunt

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Re: Solar power issues?
« Reply #1 on: March 02, 2009, 11:59:20 AM »
You see panels on roofs all over Europe so I don't know how big a problem roof panels might be. We've lived off grid on solar for 12 years and I wouldn't recommend roof panels for several reasons;
1. Several times/year we change the angle of the panels to best catch the sun for efficiency.
2. In winter we need to sweep snow off the panels.
3. In our dusty low humidity climate of colorado it's necessary to 'mop' the panels from time to time to get off the dust or pollen. Rain diesn't clean them, it just makes mud on them.
Roof panels would be pretty inaccessible to these activities.

ken

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Re: Solar power issues?
« Reply #2 on: April 08, 2009, 10:46:23 PM »
Early reports of roof leaks were probably associated with improvised mounting methods or just plane old sloppy work.  The roof leak problems have essentially been resolved, given a good installer who does the work.  However, any roof penetration can be the source of a leak, its possible.

I have to admit that any opening in a roof gets me concerned.  I have one roof mounted solar array, and a ground mounted array, so far no roof leaks in about 10 years, so far, so good.  My arrays are fixed, no adjustments are made to seasonally tweak the power output.  The ground array has the advantage of easy access, the roof array is on a steep pitch roof, not something I want to have to go fiddle with.

Having a mounting system that has an air space between the back of the panels and the roofs surface for air circulation is essential to keep the panels cooler, but that has more to do with improving the efficiency of the panel, the hotter the panel the lower the output power. 

I am not aware of any thermal expansion problems related to modern solar panels construction.  Having said that I always run a tiny bead of good silicone caulk around the panels aluminum frame to add my own barrier to moisture, call me cautious, ha.  Thin film panels seem to be particularly sensitive to any moisture intrusion, so buying a well designed panel is a good thing for long life.

Most solar panels come with a warranty these days, a guarantee that the panels power output will exceed 80 percent of its original rated power output power after 20-25 years, depending on the manufacture.  As far as I know the manufactures are honoring the guarantees, your experience may be different, depends on the company.