432 



Involves more complex mechanical apparatus, reduced 

 lifetimes of mechanical parts, power to drive the 

 tracking, additional operation and maintenance expense, 

 and sky conditions with a high ratio of direct to 

 diffuse irradiation. The energy/cost tradeoff is 

 straight forward in the additional capital costs, 

 tracking-power and O&M versus the value of the 

 additional kilowatt-hours obtainable from the trocking 

 PV receiver. In most cases examined through the 

 years, this tradeoff has favored the economics of the 

 simple fixed-tilt, flat-plate solar photovoltaic power 

 plant. 



The low-cost of SVG INTERFACE SUBSTATION part of the 

 SVG Plant is apparent in the modest materials list and 

 utility service-yard construction practices. 

 Estimating factory cost of SVUGs in million quantities 

 production might be based on manufacturing learning- 

 curves beyond today's short-run prototype/R&D shop 

 selling prices, or on a parts and operations computer 

 model analysis like that at the Jet Propulsion 

 Laboratory a decade ago in Department of Energy 

 programs, or on the cost of a comparable electrical 



product in mass production comparable in processing 



complexity, in materials, in compatible packaging, and 

 in required quantities. 



Selling prices for small quantities, from what are 

 essentially R&D prototype manufacturing facilities. 



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