Please take note that there is a difference between grounding an electrical system, and grounding for lightning. The two situations are quite different. For designing and installing a lightning protection system see NFPA 780-250. The NEC (NFPA 70) does not address lighting protection other than when it is installed beside an electrical system ground.
I am a certified electrical inspector (ICC) and electrical contractor (NM & CA). In the southwest lightning protection is a BIG thing! Wes ARRL Technical Specialist AE6ZM & VE7ELE Lincoln, CA CM98iv Placer County ARES
