Grounding, union of ground rods to metallic structures, meshes, substations, power installations and lightning arresters. Long term experience with the use for these purposes is available.
Copper coated welding wire has become common since wire welding equipment has become popular.
This wire is also sometimes used for power transmission, windings for motors or generators, instrumentation, etc. and by a few for making antennas, especially long wire antennas that need extra strength to withstand the tension without stretching excessively. These uses are limited, but very effective.