Exploring for geothermal energy potential requires drilling to collect deep rock samples.

Can Hawaiʻi get to 100% renewable energy?

From UH News, Aug 4, 2025

To understand Hawaiʻi's path to 100% renewable energy by 2045, researchers at the University of Hawaiʻi at Mānoa and other institutions co-authored a report Assessment of the Scope of Tasks to Completely Phase out Fossil Fuels in Hawaiʻi. The report addresses the state's legal mandate to generate all its electricity from renewable sources and assesses the electrical power required for Hawai‘i’s economy without using fossil fuels.

While Hawaiʻi is aiming for 100% renewable energy by 2045, it achieved 31% in 2023. Furthermore, the state consumes nearly nine times more energy than it produces, primarily relying on petroleum, which accounts for 80% of total energy consumption. 

“Through producing this report, we found that solar, wind, and batteries on their own will not scale to meet the needs we have,” said Nicole Lautze, report co-author and director of the Hawai‘i Groundwater and Geothermal Resources Center  in the UH Mānoa School of Ocean and Earth Science and Technology. “Firm (24/7) power generation, which geothermal offers, will be required for the state to achieve 100% renewable.” 

The report evaluated non-fossil fuel solutions, which include solar, wind, hydro, biomass, nuclear, geothermal and ocean. This analysis aims to stimulate conversation on how the state should prepare for a non-fossil fuel economy.  

Economic vulnerability, oil supply unreliability

According to the report’s analysis, Hawai‘i’s economy is vulnerable to structural instability within the global oil market. As Hawai‘i’s electricity prices are more than double the U.S. average, the state’s oil supplies are unreliable in source and price, and the overall global supply is not the only factor in this unreliability. Within 10–20 years, the report suggests, that reliance on oil should be phased out.

“The state should develop post-fossil fuel energy generation and economic capabilities that do not wholly depend on oil, or petroleum products,” said Peter Sternlicht, one of the report’s co-authors, and board member of Sustainable Energy Hawai‘i.

Researchers examined Hawaiʻi's economic activity, using the data from 2019, and evaluated non-fossil fuel solutions including geothermal. For each of them, the report implemented a feasible energy system scenario in Hawai‘i.

“We hope that this comprehensive report provides actionable information that our state can use to develop an effective and efficient transition plan away from fossil fuels and toward a more sustainable and stable energy future,” said Lautze.

Report details

The report includes more than 690 pages of analysis and two appendices of supporting details.

HGGRC, Sustainable Energy Hawai‘i, Geological Survey of Finland, and Azimuth Advisory Services co-authored this report, which took three years to produce. The lead author is Simon Michaux (Finland) with co-authors Peter Sternlicht (SEH), Chris Needham, Harald Sverdrup, Nicole Lautze (HGGRC), Daniel Dores (HGGRC), Stanley Osserman, Gary Rosenberg, and Alice Kim (HGGRC).

---30---

CB: Report: Hawaiʻi Needs Nuclear and Geothermal Power To Meet Renewables Mandate - Honolulu Civil Beat