In the 1980s, following an industry-wide trend, Hawaiian Electric Company applied to the Public Utilities Commission (PUC) to form a holding company as a vehicle to diversify the electric company's interests. The reorganization was approved in 1983 and Hawaiian Electric became a subsidiary of Hawaiian Electric Industries, Inc. (HEI).
The new holding company structure also allowed the HEI family to support the development of alternate energy with the formation of Hawaiian Electric Renewable Energy Systems (HERS). HERS invested millions into a wind farm at Kahuku. Though the wind farm was eventually sold and later ceased operations due to mechanical problems, it was an important investment in the development of renewable energy sources for Hawaii, and just one of many efforts Hawaiian Electric has undertaken to help the state find alternative energy sources.
The company also continued to expand its territory of service. In 1988, Maui Electric Company acquired the Lanai City power plant on the island of Lanai, and in 1989, Molokai Electric Company on the island of Molokai. With these acquisitions, all major islands in the Hawaiian chain -- with the exception of Kauai -- were now part of the service territories of Hawaiian Electric or its subsidiaries.