“Hawaii and Geothermal: What Has Been Happening?” GHC Bulletin, September 2002
Hawaii Department of Business, Economic Development and Tourism
U.S. Department of Energy, Energy Efficiency and Renewable Energy/Geothermal Technologies Program website
Hawaiian Electric Company (HECO) website
Geothermal Education Office/GeoPowering the West website
Ormat Technologies, Inc.
Geothermal energy is heat from Earth’s interior. Geothermal heat originates from Earth’s fiery formation more than four billion years ago. At Earth’s core—4,000 miles deep—temperatures may reach over 9,000 degrees Fahrenheit.