Assessment of utilization of combined heat and power systems to provide grid flexibility alongside variable renewable energy systems

Abstract

Power grids require more flexibility to adapt to the integration of variable renewable energy sources, which naturally produce inconsistent supply. Distributed energy resources installed at consumer sites can provide flexibility from the demand side. The aim of this study is to evaluate the potential of providing grid flexibility using combined heat and power (CHP) systems. A model that reproduces the operation of power sources was used to analyze the predicted lack of grid flexibility in the power system for the year 2030, and the model was used for the greater Tokyo area. We then scrutinized flexibility provision by the CHPs of four types of business facilities by tracking their operational changes in response to electricity time-of-use rates that reflect flexibility insufficiency. The nationwide potential of flexibility supply was calculated from the simulation result as well as nationwide CHP penetration data. The results show that the introduction of time-of-use rates as an economic incentive leads to a sizeable reduction in consumers’ energy costs, and the provision of flexibility depends substantially on the facilities’ heat-to-electricity ratios. We concluded that the aggregation of CHPs and sundry components, along with integrated working of various types of facilities, offers the most effective grid flexibility support.