This report sets forth the results of a study by Rice University to determine areas of the United States that were not available as potential sites for receiving antennas that are an integral part of the SPS concept. Under the current SPS program, 60 satellite-rectenna pairs would be developed. Each pair would produce 5 gigawatts of power and the rectenna would require the dedication of approximately 50,000 acres of land per site. Therefore, 60 sites of 50,000 acres each, approximately 3 million acres, will be required. This study's approach to finding where, or even if, 60 such sites existed was to determine those areas where the rectenna could not be sited. 36 variables with the potential to exclude the rectenna were mapped and coded into the Rice computer system. Some of these variables absolutely exclude a rectenna from locating within the area of its spatial influence, and other variables potentially exclude the rectenna.