Is lightning protection a factor in PV installs?
Eric Peterson| Posted inGreen Building Techniqueson
I’m planning a new home with a PV array on the roof and just wondered if lighting protection is something I need to think about? I work as a preservation carpenter for a large museum organization, and many of our buildings, especially the estates, have lighting protection installed. Chimneys and balustrades and other roof mounted structures seem to get struck fairly regularly. Any experience with lightning and PV arrays?
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Replies
Eric,
The short answer is YES; arrays must be gounded. I don't know all the details, but the details are in the NEC (National Electrical Code).
There are many grounding methods out there. Somehow the pathway needs to get to a grounding electrode (rod pounded into the ground or set into a slab). #6 copper is common. The racking systems now have small pieces set to "bite" into the rack to avoid traversing the entire rack with the #6. Until recently, you used to have the copper wire run the entire length of the rack and include a lug in every module. That raised the price with equipment and time. Much easier now with the newer accessories.
http://www.we-llc.com/products/weeb-washer
The new Midnight solar arrestors are the best in the industry for absorbing a direct hit.
http://www.midnitesolar.com/pages/pages.php?article_ID=49