The potential for commercialization of terrestrial energy systems based upon aerospace power technology's explored. Threats to the aerospace power technology industry, caused by the end of the cold war and weak world economy are described. There are also new opportunities caused by increasing terrestrial energy needs and world-wide concern for the environment. The strengths and weaknesses of the aerospace power industry in commercializing terrestrial energy technologies are reviewed. New energy efficient technologies are described. Finally, actions which will enable the aerospace power technology industry to commercialize products into terrestrial energy markets are described.