Methodologies have been developed to aid in selection of a candidate distributed generation system for use in meeting a building's electrical demand. The systems studied are comprised of a combination of microturbines and/or natural gas reciprocating engines. These systems could also be used as prime movers in a combined heat and power application. Economic optimizations have been performed in order to identify distributed generation/prime mover combinations and operating strategies that yield the lowest electrical generation cost. These optimizations take into account a finite set of operating scenarios and equipment combinations. In addition to the economic optimizations, a direct comparison of customer design considerations has been made, highlighting the advantages and disadvantages of both microturbines and reciprocating engines. In this study, the optimal system for a 9290 m2 (100,000 ft2) office building in New York City at today's natural gas prices was determined to be a combination of natural gas reciprocating engines and microturbines. This system yielded a 5% reduction in generation costs over other cases examined including all homogeneous composition systems. With an increase in natural gas prices, the optimal case changes to be comprised solely of natural gas reciprocating engines. It has been shown that many factors are important to selection of optimal equipment including the specific end use load profile, cost of fuel, and system operating strategy.
LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES
