1980 Societal Assessment of SPS

using a series of computer-generated maps which show areas of land excluded on the basis of certain criteria represented by the "exclusion variables" of Exhibit 1. Areas not identified with exclusion variables have been determined to be "eligible" for rectenna siting, pending further analysis. It has also been assumed that the eligible areas must be close enough to major electrical utility load centers to represent a reasonable solution to utility integration concerns. Thus, the need to find sufficient land for all 60 rectennas in the Reference System is one factor; suitably-located land is another. In addition to those exclusion variables which absolutely preclude rectenna siting (e.g., land traversed by interstate highways), land potentially can be excluded due to a high probability of some adverse effect arising from the siting of a rectenna (e.g., if the given piece of land being mapped contains Indian reservations). Since too little is known currently about the biological effects of SPS microwave power transmission on avian species, another category of variable, "Potential Exclusion—Impact Unknown," was created. This variable specifically excludes the flyways of migratory waterfowl, flyways which are well known and easily identified. Design/cost variables also represent possible exclusion, depending upon rectenna design/cost tradeoffs. The absolute exclusion variables were plotted on USGS 7.5 minute quad maps, as shown in Exhibit 2. Each grid cell measures 13 km on a side, roughly the size of a rectenna site. After mapping the full set of 15 absolute exclusion variables, 60 percent of CONUS was found to be nominally ineligible for rectenna siting. Of the 40 percent of the U.S. considered "eligible," large areas are in the Great Basin of the West and in the Plains states. There are, however, areas of eligible cells throughout the United States; only three states, Rhode Island, Connecticut and New Jersey are without a single eligible cell. Further, an analysis of the nine electric power planning regions within CONUS indicates an apparently adequate number of nominally eligible sites in all regions in comparison to projected electrical generation through the year 2000. Adding potential exclusion variables, 19 percent of the U.S. land area is eligible for rectenna siting. Waterfowl flyways have only a minor residual impact on the number of eligible areas in CONUS. However, the exclusion of