The objective of ASHRAE Research Project 833, the results of which are summarized in this paper, was to develop a knowledge base, tested in demonstration software, that would assist building operators in assessing the benefits of controlling electrical equipment in response to electricity rates that vary hourly. The software combines a knowledge base with computations, both of which are controlled by the user via a graphical interface. Major electrical end uses of commercial buildings are considered. The knowledge base is used to assess the trade-off of service and cost that is implicit in establishing a threshold price, above which lighting is reduced or space temperatures are allowed to deviate from setpoint. The software also evaluates thermal storage systems and on-site generation, in which occupant comfort is not affected and the systems are operated to minimize operating costs. The thermal storage and generator control algorithms have proved to be optimal under limiting cases by comparison with mixed-integer programming.

Units: I-P