Tools used for handling variable generation in the Hawaii Electric Light Co. control center

Hawaii Electric Light Co. operates an autonomous power system on the island of Hawaii with a diverse mix of generating resources. The installed wind capacity is about 20% of the typical day peak, and with a high capacity factor, it is not unusual for instantaneous penetration to exceed 20%. There is an installed capacity of 11.5 MW distributed solar photovoltaic (PV) generation, representing 6.7% and with the planned projects in the near term, distributed PV capacity will exceed 10% of a typical day peak. The variable generation from wind generation and, more recently, distributed solar photovoltaic generation has markedly affected system operation. This report will describe the operational challenges created by the variable generation resources, the existing operational techniques and tools, shortcomings and needs not addressed by the present methodologies and tools, and new tools under development in response to present needs.