Hawaii microgrid tariff second in nation, sets stage for hybrid microgrids

With the approval of a new microgrid tariff by the Hawaii Public Utilities Commission last month, the island state has been only the second in the United States to have such a model and opens up possibilities for customers to join or build hybrid microgrids well suited to emergencies.

Microgrids are like their larger counterparts in that they can generate, distribute and regulate the electricity supply. However, they do this on a smaller scale, representing a group of interconnected loads and distributed energy resources within clearly defined boundaries that, nevertheless, act as a single controllable entity. They can connect and disconnect from the larger grid as needed. This can make them invaluable for emergency use, and in recognition of that, in the future, Hawaii’s participating customers or groups could opt to seek compensation for microgrid services rendered.

“The commission’s approval of the first stage of a microgrid services tariff underscores the importance of these technically advanced systems,” Ken Aramaki, Hawaiian Electric director of transmission and distribution and interconnection planning, said. “They’ll provide more choices for customers and help Hawaii reach 100 percent renewable energy by 2045 with a grid that provides reliability and resilience for all.”

Previously, hybrid microgrids within a given microgrid boundary could only be created by Hawaiian Electric. Naturally, some customer-sited systems may already meet technical requirements; they will not be required to change their operations.

Under the terms of the tariff, there are now two types of microgrids in Hawaii: customer microgrids, where customers’ infrastructure supply all their own electricity during emergencies, and hybrid microgrids, where utility infrastructure and customer infrastructure can be combined to supply electricity to members during emergencies.

Hawaiian Electric will help identify areas on Oahu suited to the development of microgrids and work to reduce barriers to microgrid development. The company wants to see more deployed to areas susceptible to prolonged power outages caused by weather. A second phase of the PUC’s rulemaking process, somewhere down the line, will also address how the new tariff will work with customer energy programs, power purchase agreement models, and other grid service compensation mechanisms.