Revisiting InCA and The Space Power Grid

Space Solar Power (SSP) is the dream of limitless clean solar fusion electric power, beamed down to the terrestrial power grid. Periodic spikes of media attention to this dream correlate well with various initiatives for other strategic objectives, but there is also an underlying thread of serious research towards the dream. The hurdles to viable SSP are first summarized. The Space Power Grid and the Intensified Conversion Architecture (InCA) are explained in the above context, and the technical obstacles defined. Recent progress is outlined. The target is still a Specific Power of 1 kWe delivered to the terrestrial grid, per kilogram placed in orbit. Present architectures do not exceed 0.21 kWe/kg, but claim viability by projecting low material costs and extremely low launch costs. Photovoltaic convertor mass and size scale linearly with power, so that at relevant scale the probability of catastrophic collisions becomes prohibitive. The InCA promises Specific Power well over 1 using ultralight collector-concentrators and Brayton cycle conversion. The SPG is a synergistic avenue towards SSP where power is transacted through Space to turn renewable power plants into baseload suppliers, and set up a market for beamed power, preceding mass production. Breakthroughs in millimeter wave and/or laser conversion from sunlight and to grid power, are needed before a viable SSP architecture can be built. Several developments have advanced along needed directions. A Space-based market, led by military applications, may be a game-changer.