5' x 5/8" Galvanized Ground Rod - 10 Pack - Copper Bonded Lightning Protection for Home & Commercial Electrical Systems - Perfect for Electric Fence, Solar Panel & Outdoor Wiring Installations

When planning your energizer's ground field, the rule of thumb is, 3' per joule.

Example: Speedrite 18000i (18 joule) 18 x 3 = 54' of ground rod length required 

Rod should be driven in as far as possible leaving only a few inches to attach clamp and ground wire.