Hawaiian Electric Industries (HEI) is a Hawaii-based holding company whose sole operating business is regulated electric utility service. Through three utility subsidiaries — Hawaiian Electric (Oahu), Hawaii Electric Light (Big Island), and Maui Electric (Maui, Lanai, and Molokai) — HEI serves roughly 95% of Hawaii's population across approximately 474,000 customer accounts on five isolated island grids. Customers include residential, commercial, industrial, and federal government users, with the U.S. military accounting for roughly 11% of revenues. HEI recently sold its community bank subsidiary, American Savings Bank, and is winding down its non-utility subsidiaries to focus entirely on the electric utilities. The Utilities operate as regulated monopolies under the Hawaii Public Utilities Commission (PUC), which sets approved revenue targets. A sales decoupling mechanism fixes revenues regardless of actual electricity volumes consumed, insulating the Utilities from demand risk including that from widespread rooftop solar adoption. Fuel and purchased power costs are largely passed through to customers, limiting earnings exposure to oil price swings. HEI's profitability is primarily driven by the PUC-authorized rate base, the allowed return on equity (currently 9.5%), and cost management. Growth is driven by capital investment in grid modernization, renewable energy, and battery storage — all mandated by Hawaii's Renewable Portfolio Standard, which requires 100% renewable energy by 2045. Despite the renewable transition, the Utilities expect roughly 73% of net generation to come from fossil fuel oil in 2026. Hawaii's isolated island grids and dependence on imported petroleum result in some of the highest electricity prices in the U.S., averaging roughly 35.9 cents per kWh.