Lay In Lugs, for Module Grounding, Includes Screws, UL Listed, ILSCO, GBL-4DBT

ILSCO Grounding Lug GBL-4DBT Stainless Steel Thread Forming Screw
PV panel approved lug w/ 10-32 STAINLESS STEEL thread forming screw & lock-tooth washer  

Direct bury lug approved on ALL PV grounding systems

These make grounding easy. Use use the Grounding Lugs to ground the PV array (and the PV mount) as the National Electrical Code (NEC) intends.
Purchase two Grounding Lugs for each rail splice, and one Grounding Lug for each rail.