Solar Power Satellite System Definition Study
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llllEING Volume I Solar Power Satellite Phase 1, Final Report Executive Summary System Definition Study 0180-25037-1 NAS_.; (. '.-.· /tc ;> 7c BllEING GENERAL #i ELECTRIC -r-GRUMMAN Arthur D IJttle Inc IRW ,, (!USA-CR-160370) SYSTE~ DEFINITION 1: EIRCUTIVE su"~\8Y 22e GJ/15 )-15636 T-1487 MA-731T : ;TEM 3 Solar Power Satalite System Definition Study Conducted for the NASA Johnson Space Center Under Contract NASY-1 S6.l6 Volume I PHASE I, FINAL REPORT Executive Summary 0180-25037-1 February !6. 1979 Approved By: f!i::t~ Study Manager Boeing Aerospace Company Ballistic Missiles and Space Division P.O. Box 3999 Seattle. Washington 98 ! 24 01~25037-1 1.0 INTRODUCTION AND BACKGROUND I. I History --~-o.-.. ·------"_____ __ ...,_... ............. ·-- ~.... ..,.,.. ·---.... - Solar power has long been recogniud as an ideal source of energy for mankind. It is natur-.llly available and plentiful. does not disturb the envi ronment. e.g .. by creation of wastes. and is itself free. About ten years ago. a way of utilizing solar energy to gener-.tte electricity on a 24-hour continuous basis was proposed by Peter Glaser of A. D. Little. His proposal was to place the solar collectors in space. where they can collect sunlight continuously. can readily be aimed at the sun. and Figure 1. Solar Power Satellites: Th~ Principle where very brge collector areas can be obtained with relafo·ely litlle investment in material through the NASA Lewis Research Center to inves resources. Energy colleckd by these solar power tigate basic technical feasibility of the SPS concept. sat~llites (SPS's) would be transmitted to Earth by The conclusions of that study were that the system eledromagnetk .nc~ms. The original Glaser pro is tel.'hnically feasible and could provide baseload posal. and most of the subsequ1:nt studies. have electricity from solar pow>!r for use on Earth. assumed the LISI.' of radio frequency s~ stems in the Additional studies and experiments. partly funded microwave frequenc~ range. Recently. the possibil by NASA mer the period 1973 to 1975. estab ity of las-:r bt·;uning has also bc.-tc"n rt•t·ogniud. lished the feasibility of efficient energy transmis sion at micr(lwave frequencies. In 1975 a demon Thi.' solar power satellill.' principle is illus str-Jtion con<lucted at JPL trnnsmitted more than trakd in figure I. In a geostationary orbit 36.000 30 kilowatts over a distance greater than a mile km above the.- Earth ·s equator. e;Kh SPS would be with a recertion and conversion efficiency of 82 illuminated b) sunlight O\"er l/1Yi of the time and percent. in continuous linl.'-of-sight conta1:t wi1h its ground recei\·ing station. Ekctrical power produced on the In the 1975 to 1977 time period. NASA satellite by photovoltaic or heat engine conversion conducted a technical assessment of SPS and began of thl· sunlight would be converted to electromag inhouse studies at the Johnson and Marshall Space netil: energy at high efficiency. and formed into a Centers. The Department of Energy conducted its narrow bc:am precisely :iimed at the SPS ground own assessment; SPS was discussed in congressional slations. The ground station rel.'eiving antennas hearings. These activities led to development of an would re.:onvcrt the energy into electricity for dis SPS Development and Evaluation Prog;,un Plan tribution. Solar power satellites are intended to jointly sponsored by DOE and NASA. The princi serve as producers of baseload ekctricity for utility pal milestones in this plan are: se:-vice. SPS's are seen not as a substitute for other solar energy options. b~:t as a complement that Reference System Definition Report. Oct. 1978 would allow solar energy lo more completely serve (Complete) humaniiy s en~rgy nei:ds. Preliminary Program Recommendati(lns. May 1979 Updated Program Recommendations. Jan. 1980 Dr. Glasi:r's original proposal was published Final Program Recommendations. June 1980 in 1968 in Science magazine. In 1971 and l 972 a smJll contractor study team was formed including (Also during thir: period. NASA-funded Arthur D. Little. Grumman. Raytheon and Spec space transportation system studies indicated that trolab. This kam was awarded a stuJy contract the high traffic volumes required to support an SPS 0180-25037-1 program could lead to cost reduction:> far below reductions in photovoltaics mass production those projected for the space shuttle. The potential might not be achieved.) The silicon photovol for such cost reductions was seen as significant to taic system offers less risk with a more mature the economic practicality of SPS.) technology but an energy conversion system roughly 40 percent 'llore massive thJtl gallium As a result, plans were formulated by ar~nide. NASA to condud solar power satellite system definition studies in 1977 in order to support the 2. Analyses "'f the power transmission system first milestone of the DOE/NASA evaluation plan. confirmed the basic feasibility indicated by These would increase by roughly an onler of mag the earlier studies and detailed microwave link nitude the degree of depth of design and cost defi error analysis confirmed attainability of ade nition for SPS systems. One such study was quate efficiencies. Integrated power transmis awarded to Boeing through the Johnson Space sion system conceptual designs were devel Center; the other study was awarded to Rockwell oped (.'Onsidering RF. electrical, mechanical, through the Marshall Space Flight Center. These and thermal factors. studies created reference system designs including che solar power satdlitcs. ground receiving stations, 3. Space transportation systems were designed space transportation systems, space construction to accomplish the SPS transportation opera systems and other support systt>ms. The results tions at acceptabie cost. indicated that SPS's could be built by the year 2000 with a likelihood of economic benefit. The 4. Space construction approaches and construc principal findings of these studies might be summa tion base designs weri:: developed for construc rized as follows: tion of 10,000 megawatt SPS's in geosynchro nous orbit at a rate of approximately I per 1. Examination of energy conversion options led year. to a preference for silicon photovoltaics in the Boeing study. and gallium arsenide photovol TI1e principal system elements from that taics in the Rockwell study. (Both si:udies sug study were the point of departure for the current gested thermal engine SPS designs as a hedge study. The preferred SPS defined by Boeing is illus again,t the possibility thar expe,'.ted cost trated in figure 2. ~-~~- .. .. .. I lo .. ' - • l -~I ...... 4.. STlllNGS/15m l EllMEOIATE SEGME .. 1111 ! " - [ i j] I GMENT NTSlllAY 10- y ·ll'"'lrl1-- . Y STRING LENGTH '-I $Tllllll.-.sl15m··- ENO SEGMENT Figure 2. Reference Photovoltaic System Description 2 1.2 Objectives 4. Defme the most economically prudent path to minimizing these unl.'ertainties to the point The overall intent of the systems defmition that confident decisions can be made to pro studie-s, past and present, may be summarized as ceed or not to proceed with development of follows: this energy system. I. Assess the technical feasibility of solar power The specific objectives of the present study satellites based on forecasts of technical capa are: bility in the various applicable technologies. Select the most appropriate technological (I) to verify, maintain and update the presently paths leading to the most environmentally defined elements of the system, benign and economically practical systems. (2) complete the definition of the total system. Define the areas of high leverage research. and (3) prepare a series of plans required for technol- 2. Define the characteristics of SPS systems that ogy advancement and SPS program may be derived if a development were to pro implementation. ceed. Assess perfonnance, cost. operational characteristics, reliability, and the suitability Phase I of the present study. reported here of SPS's as power generators for typical com with, has concentrated on the first two objectives. mercial electricity grids. Phase II will emphasize end-to-end operations analyses and the third objective. These Qbjectives 3. Assess the uncertainties inherent in the sys and the timing of the study are designed to support tem characteristics forecasts, based on tech the NASA program recommendations in fulfill nological uncertainties, on cost estimating ment of the DOE/NASA evaluation plan. uncertainties, and on uncertainties that arise from incompleteness in the data base. 2.0 STUDY APPROACH AND STUDY TEAM The JSC/Boeing and MSFC/Rockwell SPS NASA in developing the reference system report, system definition studies of 1977 and early 1978 beginning with a thorough critique of the JSC/ proceeded largely independently of one another Boeing reference system, followed by analyses of and developed system concepts with a number of options and critique items. The reference design significant differences. NASA then developed a ref was updated at the end of Phase I. The overdll erence SPS system description based on NASA ~chedule is shown in figure 3. inhouse studies as well as on Boeing and Rockwell contract results. The Study Contract Team included Boeing as prime contractor and General Electric, Grum The present study is divided into two man, Arthur D. Little, and TRW as subcontractors. phases; the first lasted 7 months and the second Principal task areas and the study team leaders for will last 9 months. Phase I accomplished additional each contractor are shown in figure 4. analyses of the options and issues identified by 3 0180-25037-1 _, -· -· -· IUCllllC ....... &-0.UTIU .....-.uv« Figure 4. Study Contract Team Organization (Phase I Tasks Shown) Figure 3. Study Plan Overview J.O STUDY RESULTS The preS4!ntation of study results in this be built and tested to verify annealability as executive summary ha~ been grouped under three well as survivability of the rest of the array major headings: under annealing conditions.