Advancing Toward Sustainability Goals at the University of California, Irvine

Abstract

The carbon reduction and sustainability goals of the University of California, Irvine require increased penetrations of intermittent renewables on the campus microgrid. These increased intermittent renewables create operational challenges related to conventional energy resources. To study these operational challenges, a holistic campus resource dispatch model was developed. The campus energy resources consist of a microgrid with ten 12 kV circuits emanating from one substation, 4 MW of solar photovoltaic, a central combined heat and power plant (19 MW), a district heating and cooling system, and an electric chiller-thermal energy storage system that provide electricity, heat, and cooling. The holistic model includes dynamic models of the combined heat and power (CHP) plant, the electric chiller-thermal energy storage system, and various renewable resources. In addition, models for complimentary technologies were also created to investigate their potential to increase renewable penetration on the campus microgrid. These include battery energy storage, demand response, and energy efficiency. Simulations with the holistic campus resource model revealed several important conclusions: (1) Regardless of renewable resource type, impacts on the CHP plant remains the same, i.e., increased renewable penetrations create reduced CHP plant capacity factors; (2) Local two axis CPV provides lower costs of electricity than local fixed PV at renewable penetrations below 23% after which local fixed PV provides a lower cost of electricity (3) Introduction of a battery into the campus microgrid achieves higher renewable penetrations and improves the operation of CHP plant; and (4) Electric energy storage does not always prove cost effective (i.e., At low renewable penetrations, electric energy storage is not cost effective; At 17% renewable penetration, electric energy storage begins to become cost effective).