In the distant future, no one needs to work. Energy is available wherever people can set up a solar panel, windmill, or hydro-turbine. Artificial Intelligence (AI) units, distant descendants of today’s 3D printers, are capable of producing anything a person can program into them. Just by asking, anyone can have anything they want. People trade energy credits or donate energy to projects that interest them.
See for example HBR on "Computers Create Jobs and Inequality at the Same Time".