Power is no longer an issue in the 27th century. Nuclear fusion is the most widespread means of power generation. Long-distance transportation uses magnetic fields, and the energy carried in those fields is converted to electricity for end-user consumption.
Spaceships must generate their power using nuclear fusion as well. Ramjets use fusion to generate mostly kinetic energy to accelerate and electromagnetic energy to power the enormous ramscoop fields and powerful communication lasers. Colony ships carry smaller fusion reactors to produce the electricity required to operate the ship.
Moving consumers, like vehicles and wearable computers, obtain their energy from electricity broadcast stations spread across the globe.