Aluminum Frame Work

    Now that the concrete part is out of the way, something is needed to attached to solar panels to, like a frame.  I considered a range of ways of doing this.  The frame could be built from pressure treated lumber, or welded steel, or even plastic.  However during my reading of a "lessons learned" paper from the 1970's solar hot water systems failures, I read a little piece of advice.  The advice was to use only very durable materials for the harsh outdoor environment.  Specifically, the authors of the article had great experience with aluminum and stainless steel.

    The panels that I am planning on purchasing are from a company called Heliodyne.  They make a great frame for about $500.  The frame has aluminum posts and stainless steel fasteners.  It is very nice.  However, the frame didn't offer much flexibility for mounting other objects.  So if I wanted to mount a heat dump on the same frame, it would be tricky because there are no additional mounting points.

   So I decided to make my own frame which is inspired by the Heliodyne frame.  My frame is made from aluminum extruded sections from Misumi and has stainless steel fasteners.  It also cost roughly $500.  The Misumi extrusions are very similar to a competitor's offering called 80/20 which will be familiar to most Mechanical Engineers.  It is the adult version of Legos or Erector sets.  All the pieces are pre-cut to your specified lengths and all you need to do when they arrive is assemble them as shown below.

 

  The aluminum extrusions and their mounting brackets bolted directly to the threaded rod sections that are anchored into the concrete.  Assembly was easily.  I just needed to adjust a little bit for the concrete piers not being of exactly the right height.

 

    To reduce the risk of a lateral load bringing down the framework, diagonal braces were placed on the left and the right.  The commercial Heliodyne framework didn't have this feature and that made me a little nervous about buying them.  Normally, there shouldn't be any side load on the frame, but it is still nice to have some added support.  

    The biggest annoyance that I had was with the 12 foot long aluminum extrusions.  These were too long to ship by normal UPS.  So they had to be shipped with a trucking service for $170 which is more than the $150 I paid for the parts.  In hind-sight, I should have made these into two shorter lengths.  That is how Heliodyne ships these pieces.  Live and Learn.

 

  The aluminum extrusion have T-slots down their length.  This allows a T-nut to be dropped into the slot and I will be easily able to screw in the panels.

   Up next, time to put that sidewalk back in.