STANDBY POWER-GENERATION UNDER UTILITY CURTAILMENT CONTRACT AGREEMENTS

Many utilities in the United States offer large industrial and commerc ial customers power sales contracts which have attractive rates under a curtailment requirement, This curtailment requirement allows the uti lity to require the customer to reduce its power demand to a predeterm ined level within a specific time period, If the required curtailment is not achieved by the customer within the allocated time period, stif f financial penalties are usually enforced by the utility, The attract iveness of the contract rates usually is proportional to the amount of curtailment required, To take advantage of these attractive rates, a customer must be able to withstand the curtailment without supplementa l generation or must add standby generation to meet its needs, Obvious ly, the cost of the curtailments to the customer should not exceed the economic benefits of reduced rates, This paper reviews the alternativ es faced by a curtailment contract customer together with potential lo ad-shedding and standby-generation system designs, An example of imple menting a curtailment contract at an existing industrial facility is p resented, The example facility, Boeing Helicopters, Philadelphia, PA, required both load shedding and standby generation, The load-shedding scheme is fairly complex and is controlled by a programmable logic con troller (PLC), The standby-generation and load-shedding systems for th e example facility are examined in detail, Also, lessons learned from implementing the required modifications to the example facility are di scussed.