Commercial electric energy from space (1 kW-hr cost $0.002-0.003) is available in the following decade

The solar power system (SPS) is the most promising way to overcome global environmental and economic problems. Different SPS concepts are compared briefly. Direct conversion of solar energy to energy of a high-power laser beam has the advantage of high efficiency and precise energy transportation. Optical phase conjugation permits the use of acceptable cheap optics for energy transportation. Conversion of laser energy to electric energy is provided by photovoltaic cells. Technical consideration concerns the key components and features of the system. A space-based module of the system should satisfy several requirements. A thin-film large-scale collector should keep its form and must be oriented to the Sun. At the same time this collector should be transparent for the output laser beam. The laser should be aligned with the collector and with the receiving ground-based station. Optical phase conjugation can be fruitful using an appropriate reference beam. All-weatherness is the problem for energy transportation. These and other issues have been analyzed in the paper. The most interesting and important result arises from economic assessments. Preliminary analysis shows 1 kWe cost $300-500 and 1 kW-hr cost $0.002-0.003. We have estimated an R&D program and following, an expected minimum net profit $450-500 billion. Our general analysis shows that commercial electrical power supply for terrestrial consumers could be available in the following decade