The anticipated global demand growth for energy, and electricity in particular, is mapped for the coming 20 years. Five critical issues implied by this forecast are then spelled out: uncertainty, security of energy supply, energy financing, and the role of nuclear and renewable energy. Finally, based on a review of the energy revolutions which the human race has experienced during history, the paper sketches a long term energy future. It suggests the possibility of a new energy era in the 21st century with electricity and hydrogen as the main final energy and nuclear and renewables as the main primary energy, providing, coincidentally, a solution to the CO2 issues that loom so importantly at the end of the 20th century.