0191 -9067/82/010031-14$03.00/0 Copyright © 1982 SUNSAT Energy Council POWER AVAILABILITY AT TERRESTRIAL RECEPTOR SITES FOR LASER-POWER TRANSMISSION FROM THE SATELLITE POWER SYSTEM R. E. BEVERLY III Consulting Physicist 1891 Fishinger Road Columbus, Ohio 43221 Abstract — Laser power transmission from the satellite power system (SPS) to terrestrial receptor sites can be subject to severe attenuation due to various meteorological conditions. Using mitigation techniques (1) which minimize the deleterious effects of inclimate weather on propagation, preliminary receptor siting criteria were defined and 22 candidate sites in the contiguous United States were selected for detailed study. A power availability model has been developed which uses statistical meteorological data for each site to calculate the annual and seasonal power availability (average transmission efficiency assuming constant power beaming) and the frequency for which the transmission efficiency exceeds a given value for a specified persistence time. The results of this work enable us to define siting criteria and laser parameters such that the power availability is comparable to the microwave-SPS concept or to conventional electric-power plants. The laser-SPS concept must be based on the use of 2 or 3 dedicated sites separated by a centroid radius of 50 to 300 miles for each transmitted beam to achieve an 80% frequency for the transmission efficiency to equal or exceed 80% to one of the sites. Frequent beam switching between sites is required; for many sites, the persistence time for transmission to one site is less than 8 h. INTRODUCTION System studies of laser-SPS concepts have generally neglected variations in the transmission efficiency caused by different meteorological conditions. Quoted transmission efficiencies usually consider the beam attenuation due to molecular absorption only, ignoring the time-dependent effects of natural aerosols such as haze, fog, clouds, and precipitation. During periods of heavy cloud cover or precipitation, however, a severe loss in transmission efficiency will occur because of aerosol absorption and scattering (1). In this study, a statistical model is proposed which relates temporal transmission parameters to observable meteorological data in an effort to bound the influence of inclimate weather on power availability at the receptor. We begin by defining preliminary receptor siting criteria which are used later in the selection of representative locations for application of the statistical model. The power-availability model is developed followed by analysis of the statistical results on a regional basis. Multiple-receptor siting criteria used in conjunction with beam switching are then defined so that the laser-SPS concept is viable in terms of power available to the utility electric-power grid. Research supported by Rockwell International Corporation, Space Operations and Satellite Systems Division (NASA/MSFC Prime Contract No. NAS 8-32475).
RkJQdWJsaXNoZXIy MTU5NjU0Mg==