In the United States, 29 states, Washington, D.C. and three territories have adopted a mandatory Renewable Portfolio Standard (RPS) for their electric power systems, while eight states and one territory have set renewable energy goals. Many foreign nations have adopted an RPS as well. Thus far, almost all RPSs across the United States have met their interim goals with targets and timetables that vary widely. Hawaii’s RPS is the most ambitious, with a 100% target set for 2045 (though Vermont set a 75% target for 2032). This paper provides a case study of the Hawai’i RPS. The paper focuses on geographical issues and perspectives that may tease out the course of the states’ electricity future: sensitivity to climate change, population distribution, interisland rivalries, as well as the need for greater energy storage and complementary policies. An important complexity is the challenge of meeting electricity demand on six separate Hawaiian Islands (because of the lack of an interisland transmission cable), although all of them have substantial renewable energy resources.