As solar, wind and geothermal energy capture improve and as large-scale energy storage becomes low cost and man-portable, each person's need for electricity will become more localized. Eventually, each business and home will become energy independent; generating its own daily need and storing their own reserves. The national grid will remain (if at all) only for use in unusual situations.
With inexpensive and scale-able electricity available everywhere, water purification and indoor hydroponic farming also become portable.
This frees people from the city high rises and suburban sprawls. We get to live comfortably even in the most remote and inhospitable places.
Information, in the form of voice communications, email and internet access, has already become wireless, leaving its wired roots in place only where speed and reliability trump convenience.
Cables will continue to be used for power transportation but they will be only one of the available options and will therefore find their markets. For example, cold-climate inland industrial sites may use cables to receive power from coastal tidal generator farms and warmer-climate solar farms.
I don't think that we will find new uses for cables as we move further into the wireless age. Instead, power poles, transformers and all their connective wiring will fade into history like horse-drawn carriages and open sewers.