Control Methodologies for Minimizing Cost of Energy using Distributed Generation in the Built Environment

Distributed generation can provide many benefits over traditional central generation such as increased reliability and efficiency while reducing emissions. Despite these potential benefits, distributed generation is generally not purchased unless it reduces energy costs. The Capstone C65 microturbine is a readily available example of a distributed generator capable of producing 65 KW and high quality heat that can be captured with ancillary technologies to meet the electrical, heating, and cooling load of a building. Dispatch strategies can be designed such that distributed generation technologies reduce overall facility energy costs. In this paper, a C65 microturbine is dispatched using different control methodologies, reducing the cost of energy to the facility.  Several industrial and commercial facilities are simulated using acquired electrical, heating, and cooling load data. Industrial and commercial utility rate structures are modeled after Southern California Edison tariffs and used to find energy costs for the simulated buildings and corresponding microturbine dispatch.  Through installation of C65 microturbines and use of dispatch strategies discussed here, savings are found, and an economic assessment of the microturbine and other ancillary technologies is performed. Results show that energy savings are maximized when the C65 is used to reduce demand charges and supply energy when utility energy is most expensive. Dynamic building loads are more likely to experience savings than less dynamic loads. Time of use electrical rate structures usually allow for larger savings to be realized than non time of use. Using these dispatch strategies, a stronger economic case can be made for distributed generation.