Geothermal FAQs
What is geothermal energy?
Critical to Hawai‘i’s sustainable energy future, geothermal energy – or heat within the earth – is a natural renewable resource because it is continuously being produced due to the gradual decay of radioactive particles in the earth’s core. The temperature of the earth’s core is as hot as the surface of the sun, and rocks and water closer to the surface absorb heat from magma deep underground, according to the U.S Energy Information Administration.
In some regions where the earth’s crust is thin or fractured, or where magma
bodies are close to the surface, there are high temperature gradients towards the surface. Deep faults, rock fractures and pores allow groundwater to percolate toward the heat source and become heated to high temperatures. Some of this hot geothermal water travels back to the surface through buoyancy effects and can appear as hot springs, mud pools, geysers, or fumaroles. If the rising hot water meets an extensively fractured or permeable rock zone, the heated water will fill pores and fractures and form a geothermal reservoir. These reservoirs are much hotter than surface hot springs, reaching more than 350°C, and are potentially an accessible source of energy.
How is geothermal energy harvested?
We can safely harvest geothermal energy when wells reaching deep into volcanic rocktap steam and hot water from these reservoirs of geothermal fluid, these wells allow us to bring this hot steam and water to the surface, which is used to turn turbines and generate electricity. There are three types of geothermal power plants: dry steam, flash steam and binary-cycle, these can also be combined in some circumstances.
Although geothermal power production is a mature and commercially proven system, advances in technology continue to make this process even more efficient and cost effective, while mitigating the impact on the environment.
Where is geothermal energy found?
Geothermal energy is common around volcanic activity and tectonic plates in the Pacific,where hot magma is found near the earth’s surface. U.S. geothermal power plants aremostly located in the West and Hawai‘i. According to a 2021 report by the National Renewable Energy Laboratory (NREL), California and Nevada contribute more than 90% of U.S. geothermal power generation, with additional contributions from plants in Alaska, Hawai‘i, Idaho, New Mexico, Oregon, and Utah.
Who owns geothermal energy?
In Hawai‘i, geothermal energy is an indigenous resource owned by the public and Native Hawaiians.
What are the primary benefits of geothermal energy?
Unlike intermittent renewable sources of energy that are subject to weather conditions and other variables, geothermal power is available consistently, 24 hours a day, 7 days a week, all year around, making it a firm, reliable and cost- effective, locally available baseload power source that can replace fossil fuel and stabilize the grid with it’s increasing intermittent other renewable generation sources for electricity production such as wind and solar.
What is firm power?
Unlike intermittent renewable sources of energy that are subject to weather conditions and other variables, geothermal power is available consistently, 24 hours a day, 7 days a week, all year around, making it a firm, reliable and cost- effective, locally available baseload power source that can replace fossil fuel and stabilize the grid.
How does geothermal energy support economic development?
Geothermal power serves as an economic engine for community and small business development. With billions of dollars leaving Hawai‘i every year to pay for imported fossil fuels, geothermal is a safe, lower cost firm power baseload. The state’s vast and valuable renewable energy resources will ensure that more of that money stays in our communities. Additional economic activity, jobs, and fair and reasonable costs for energy will make life more affordable for Hawai‘i families.
What are Hawai‘i’s current energy sources?
Oil and coal imports make up over 80% of all energy used in Hawai‘i forelectricity and transportation, according to Hawaiian Electric – this accountsfor the state ranking the highest in the U.S. for its average electricity pricesand energy insecurity. In 2024, the percentage of Hawaiian Electric generationfrom renewable energy was 30.8% onO‘ahu, 41.1% on Maui, and 58.7% on Hawai‘iIsland. Geothermal accounted for just 19.1% of the total system generation mixon Hawai‘i Island.
Are there emissions from geothermal energy production?
Geothermal power plants have low emission levels. Geothermal powerplants emit 97% less acid rain-causing sulfurcompounds and about 99%less carbon dioxide than the equivalent firm, baseload fossil fuel powerplants of similar size, according to the U.S. Energy InformationAdministration.
How do geothermal plants reduce emissions?
Geothermal plants reinject most of the geothermal steam and water that theyuse back into the earth – this varies depending on which technology is chosen,helping renew the geothermal resource and reduce emissions. In additionscrubbers and other technology at geothermal power plants help removehydrogen sulfide that occurs naturally in geothermal reservoirs and manageother non-condensable gases. Due to the highly centralized nature ofgeothermal resource development, the environmental impact of plants can bereduced to an acceptable level, according to the U.S. Fish & Wildlife Service.
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Are there gases naturally emitted from volcanic eruptions?
According to USGS, 99% of the gas molecules emitted during a volcaniceruption are water vapor, carbon dioxide, and sulfur dioxide. Hydrogen sulfideand hydrogen halides can also be emitted from volcanoes.
What geothermal production currently exists in Hawai‘i?
The Kīlauea East Rift Zone is the only region developed for geothermal energy in Hawai‘i, and has all the attributes necessary for energy generation, according to the Hawai‘i State Energy Office. Geothermal development in Hawai‘i started in the 1970s, when the University of Hawai‘i drilled an experimental well (HGP-A) in the Kīlauea East Rift Zone in 1976 that grew into a small-scale power plant in the 1980s. Since 1993, Puna Geothermal Venture (PGV) has operated Hawai‘i’s only geothermal power plant nearby with a 38 MW contract capacity, although its production was temporarily interrupted following the 2018 eruption of Kīlauea. Production resumed after safeguardswere put in place. Geothermal technology continues to advance, making itsafe and reliable.
What are Hawai‘i’s Renewable Portfolio Standards?
Hawai‘i is committed to achieving the nation’s first-ever 100% Renewable Portfolio Standards (RPS) under the Hawai‘i Clean Energy Initiative (HCEI) by the year 2045 (2035 for neighbor island communities). We must continue to replace oil and coal imports with a diverse mix of renewable energy sources such as wind and ocean energy, solar, biofuels, and geothermal power to reduce our energy vulnerability and make the islands more resilient.
What is Power For the People?
Power For the People is a movement to create sustainable systems for renewable energy generation, with Native Hawaiians leading the development of their land and natural resources. This initiative is led by WaikāConsulting, LLC, a company formed by Innovations Development Group (IDG), a Hawai‘i- based and Native Hawaiian-owned renewable energy development company established in 1998 with extensive global experience.
How does Waikā’s Native to Native (N2N) Business Development Model work?
Waikā’s Native (N2N) Business Development Model aims to prioritize and empower Indigenous communities in Hawai‘i and the Pacific, helping them manage their own resources in their own way, guided by their own values. Based on the United Nations Declaration on the Rights of Indigenous Peoples, N2N brings native land and resource owners together with equitable development opportunities in culturally and environmentally appropriate ways, with the goal of sustainability, resilience and long-term economic growth and prosperity.
In close consultation with Hawai‘i cultural advisors and community leaders, Waikā understands the importance of working together in a transparent process to be responsible stewards of Tūtū Pele’s powerful gifts to her people for the benefit of all stakeholders and future generations.
Has this model been implemented before?
WaikWaikā’s team has successfully implemented the N2N model in New Zealand (Aotearoa) at the invitation of the late Te Arikinui Dame Te Atairangikaahu (Māori Queen from 1966-2006) in 2000 to help develop the geothermal resources of the Māori Trusts.
Building close working relationships with top-tier experts at the University of Auckland Geosciences Department, Waikā and IDG have been involved with severalgeothermal projects throughout the planning, consultation and development phases.One plant is already operational (Te Ahi O Maui), andanother is under development(Taheke 8C).
Each project exemplifies the power of the N2N approach: low environmental impact, cultural protections and long-term benefits to host communities. In addition to strong relationships between the Native Hawaiian and Māori peoples and deeply shared cultural values, New Zealand provides an ideal model – it is also an island nation, has more than 1,000 MW of geothermal in operation, with over 300 MW more under development, resulting in some of the lowest energy costs in the world.