For an example of how thick 24AWG wire is (22 is thicker), your standard CAT5E wire is 8 strands of 24AWG, so with the current-standard USB wiring of VCC (5v DC pos), Data (neg), Data (pos), GND (5v DC neg), it'd be ~half as thick as CatV (but would probably have different shielding). However, according to http://pinoutsguide.com/Slots/usb_3_0_connector_pinout.shtml , the powered USB 3.0 connector has 11 pins, which would be ~lamp cord thickness, or probably comparable to those ~10ft USB printer cables.
Consider how thick overhead power lines are and how much power they carry in watts, and how thick + long your vacuum cleaner cord is with how much that carries (a Dyson DC33 takes 1190 watts): http://www.cockeyed.com/science/power_use_database/dyson_vac...
For an example of how thick 24AWG wire is (22 is thicker), your standard CAT5E wire is 8 strands of 24AWG, so with the current-standard USB wiring of VCC (5v DC pos), Data (neg), Data (pos), GND (5v DC neg), it'd be ~half as thick as CatV (but would probably have different shielding). However, according to http://pinoutsguide.com/Slots/usb_3_0_connector_pinout.shtml , the powered USB 3.0 connector has 11 pins, which would be ~lamp cord thickness, or probably comparable to those ~10ft USB printer cables.
Consider how thick overhead power lines are and how much power they carry in watts, and how thick + long your vacuum cleaner cord is with how much that carries (a Dyson DC33 takes 1190 watts): http://www.cockeyed.com/science/power_use_database/dyson_vac...
Here is a good primer on wire capacity and how it relates to volts, amps, watts, and wire diameter: http://www.rowand.net/Shop/Tech/WireCapacityChart.htm
TL;DR totally possible with 20vdc to use a wire thinner than a BIC pen to deliver 100w ~6ft in addition to high-speed data.