I wonder if this could be the first step in harnessing lightning energy.
"A single lightning strike, while fast and bright, contains very little energy by the time it gets down to earth, and dozens of lightning towers like those used in the system tested by AEHI would be needed to operate five 100-watt light bulbs for the course of a year."
As I understand it, most of the energy from a lightning strike is turned into heat.
"A lightning rocket is a rocket that unravels a conductor, such as a fine copper wire, as it ascends, to conduct lightning charges to the ground. Lightning strikes derived from this process are called "triggered lightning.""
I like the idea of a longer lasting solution, though the tethers would need to be high-temp superconducting cables. The wires in triggered lightning vaporize and the energy is mostly lost to heat.