Thoughts on Solar

The Web is littered with sites proclaiming the benefits of solar as a Do-It-Yourself project and we have previously written about the perils of trying to do solar yourself.  But the recent windstorm in Pasadena provided dramatic proof that some things in life should be left to the pros - and solar is one of them.

Take this installation for example - in a lovely part of Pasadena, the previous homeowner designed and installed this system which had a number of significant problems from the get-go.  Here is the view of the site from the north looking south:

The panels that are mounted on the garage go all the way to the ridge, exposing them to higher wind forces.  There are enormous trees to the west and south-east that will provide significant amounts of shade.  The panels on the main roof (that mostly shaded shiny spot in front of the palm tree) are even worse as they are directly facing the tree to the south.  Indeed, from this view from the south, the panels on the main roof are completely invisible:

The array on the garage is pitched at 18° whereas the array on the main roof is completely flat.  Both arrays feed the same inverter which had only one MPPT channel - meaning that this system was never able to function at maximum efficiency.  Not a good design.

Now factor in the force of once-in-a-decade winds and life takes a definite turn for the worse.  The new homeowner called us to come out and assess the damage. Here’s how the array on the garage appeared when we arrived:

It doesn’t look any better in the other direction:

What happened here?

This array was attached to the roof using angle-iron from the local hardware store and simple wood screws, not lag bolts, to keep that hardware in place.  Here’s a close-up showing this homebrew attachment “system":

Those simple wood screws are a poor substitute for proper lag bolts but the previous homeowner didn’t even give his system a fighting chance as he ignored the rafters altogether (even though they were clearly visible) and simple screwed his gear into the plywood under the shingles. The result was as predictable as it was unfortunate:

Moral of the story?  The cost of adding solar professionally continues to drop, whereas the cost of doing it wrong is as steep as it ever was.

It was only good luck that prevented these panels from flying into the neighbor’s back yard.  If the wind had come during the day when the panels were generating power (instead of the middle of the night) the possibility of arcing and fire could have made things much worse.

So please, if you are thinking of adding solar as a DIY project this year, think again and call a pro.