Sell bare copper wire and grounding conductor.

Electrical rooms produce short cut lengths and leftover coil from grounding electrode conductors and equipment bonding jumpers. Substations and plant yards produce heavier conductor from ground grids, often in tails after a grid is modified.

Telecom rooms are another source. A central office or equipment room being cleared can hold busbar, grounding conductor and clean copper that has never been outdoors.

• Grounding electrode conductor in 2 AWG to 3/0.
• Ground grid conductor in 2/0 and 4/0, often in short tails.
• Bare bonding jumpers from equipment and structural steel.
• Coils left over from a service or panel replacement.

Bare copper stays a cable lot while it is continuous and identifiable. A 60 ft coil of 4/0 that was never installed is worth reviewing as conductor. The same coil cut into a dozen grid tails is reviewed as copper by weight.

Corrosion is the other variable. Buried copper comes out with green patina and soil attached; that is normal, but heavy pitting at the ends changes what the conductor can be used for.

Keep factory coils separate from cut tails. Mixing them in one box usually means the whole lot is valued as metal.

For continuous bare copper, length and gauge are checked against weight using published conductor weights. For tails, weight is the measure and the count is secondary.

Say which you have. A seller who describes forty short tails as four hundred feet of ground grid is describing a different lot from the one on the floor.