Terrestrial Solar Electric Power 24 Hours per Day Using 40% Efficient GaSb Concentrator Photovoltaic (CPV) Cells

A plausible concept for a first space Solar Power Satellite demonstration is presented. The designed satellite is similar in size to a direct broadcast communication satellite. It uses a 40 kW solar array to provide power to a 20 kW IR laser. Because the dispersion of the eye safe 1.6 micron IR laser beam is much less than the dispersion for a microwave beam, the spot size on earth from GEO is only tens of meters in diameter rather than several km. Even though the laser intensity on the ground will be low, nevertheless, modules with concentrating lenses at the ground can boost the intensity on IR GaSb PV cells and could still deliver 8 KW of solar power 24 hours per day for a first space to ground solar power satellite demonstration.