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Title: Preliminary assessment of small steam Rankine and Brayton point-focusing solar modules

Technical Report ·
OSTI ID:5926622

A preliminary assessment of three conceptual point-focusing distributed solar modules is presented. The basic power conversion units consist of small Brayton or Rankine engines individually coupled to two-axis, tracking, point-focusing solar collectors. An array of such modules can be linked together, via electric transport, to form a small power station. Each module also can be utilized, on a stand-alone basis, as an individual power source. The technical evaluation and economic analysis are treated separately. Each system concept was optimized by maximizing the thermal output per unit of concentrator area. System performance was then simulated based on the insolation data recorded at Barstow, California (in 1976). Parametric studies concerning concentrator quality and power conversion efficiency were conducted to provide relevant sensitivity relationships and trade-off information. Hardware cost targets were assessed according to the system energy production rate (kWe-hr/yr), and a range of projected energy cost levels (mills/kWe-hr). The trade-off relationship can be utilized as a realistic guideline for establishing concentrator manufacturing requirements and power conversion development targets. The justified capital cost of small (15 kWe output) gas Brayton systems at 816/sup 0/C (1500/sup 0/F) and steam Rankine systems at 538/sup 0/C (1000/sup 0/F) has been compared for a range of energy cost values. The results obtained indicate that the Brayton system merits a higher capital cost than the Rankine system for an energy cost target of 50 mills/kWe-hr, if the concentrator quality is in the range of 1 to 4 mrad.

Research Organization:
Jet Propulsion Lab., Pasadena, CA (USA); National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
DOE Contract Number:
EX-76-A-29-1060
OSTI ID:
5926622
Report Number(s):
DOE/JPL-1060-16
Country of Publication:
United States
Language:
English