Merlin 1C in its Falcon 9 first stage configuration has a thrust at sea level of 95,000 lbs, a vacuum thrust of over 108,000 pounds, vacuum specific impulse of 304 seconds and sea level thrust to weight ratio of 92. In generating this thrust, Merlin consumes 350 lbs/second of propellant and the chamber and nozzle, cooled by 100 lbs/sec of kerosene, are capable of absorbing 10 MW of heat energy. In 2008, SpaceX targets the manufacture of approximately 50 booster engines, a number that exceeds the output of any country except Russia. New cooling for the Merlin 1C allows for higher performance without significantly increasing engine mass compared to the Merlin 1A.
A planned turbopump upgrade in 2009 will improve the thrust by over 20% and the thrust to weight ratio by approximately 25%.
Colony Worlds discusses the space based solar power plans. He suggests placing the earth based collection systems over the ocean. I believe that using lasers to transmit the power from space would be better and then the system would not need large collection rectennas.