Summary

How much and what kind of commercial energy is needed to enable global energy prosperity, and possibly global economic prosperity, by the middle of the 21st century? Economic prosperity requires approximately 6 kWt of thermal commercial power per person or ∼2 kWe of electric power per person. A prosperous world of 10 billion people in 2050 will require ∼60 terawatts (TWt) of commercial thermal power or 20 TWe of electric power. What are the options for providing the necessary power and energy by the middle of the 21st century and for centuries thereafter? The twenty three options analyzed for commercial power fall under the five general categories of (1) mixed and carbon-based, (2) terrestrial renewable, (3) terrestrial solar, (4) nuclear fission and fusion, and (5) space and lunar solar power systems. It is argued that the only practical and acceptable option for providing such large flows of commercial power is to develop the Moon as the platform for gathering solar energy and supplying that energy, via low-intensity beams of microwaves, to receivers, termed “rectennas”, on Earth. The rectennas will output clean and affordable electric power to local grids. No pollution (greenhouse, ash, acids, radioactive wastes, dust) will be produced. All energy inputs to the biosphere of the net new electric power can be completely balanced on a global basis without “greenhouse-like” heating of the biosphere.