Unlocking Hawaii’s Hidden Cooling Power: New Report Reveals Huge Potential for Geothermal Cooling on Oahu (2025)
By: Robert Buluma
Could the same volcanic islands that give Hawaii its famous heat also provide the solution to cool its buildings , without crushing the electric grid?
A groundbreaking new report released December 8, 2025, by the University of Hawaiʻi at Mānoa (UHM) and Lawrence Berkeley National Laboratory (LBNL) says the answer is a resounding yes. Shallow geothermal heat exchangers (GHEs) , also known as geothermal heat pumps or ground-source heat pumps ,could dramatically cut cooling costs and electricity demand across Oahu, especially for large buildings like schools, military bases, and university facilities.
Here’s everything you need to know about this exciting development in Hawaii geothermal cooling technology.
Why Hawaii Is Perfectly Suited for Geothermal Cooling
Most of the world uses geothermal heat pumps for heating in cold climates. Hawaii flips the script: we need cooling 365 days a year.
Traditional air-conditioning puts enormous strain on Hawaiian Electric’s grid, especially during peak afternoon hours. Geothermal heat pumps work like a refrigerator in reverse ,they move heat from your building into the ground instead of into already-hot outside air.
The magic ingredient? Hawaii’s young volcanic rock is extremely permeable, and the islands have massive natural groundwater flow (think underground rivers inside the lava rock). This constant flow of cool groundwater sweeps away the heat that the system dumps underground, preventing heat buildup and keeping the system efficient for decades.
As LBNL staff scientist Christine Doughty explains:
“High-temperature geothermal needs deep drilling for electricity, but low-temperature geothermal , accessible just tens or hundreds of feet below the surface , is ideal for building cooling and can greatly lessen loads on Hawaii’s electric grid.”
Key Findings of the 2025 Hawaii Geothermal Cooling Report
The study, funded through the U.S. Department of Energy’s ETIPP program (Energy Technology Innovation Partnership Project), produced the first island-wide favorability maps for both open-loop and closed-loop geothermal heat exchanger systems on Oahu.
Highlights:
Large portions of coastal and central Oahu rank highly favorable (dark green on the maps) for closed-loop systems
High groundwater flow in volcanic aquifers is the #1 factor for long-term success
Restricted watersheds and potable-water protection zones limit some areas, but still leave thousands of acres viable
Potential customers overlay (DoD bases, public/private schools, university campuses) lines up almost perfectly with high-favorability zones
Researchers zeroed in on the iconic Stan Sheriff Center a 10,300-seat arena with massive year-round cooling needs ,as a real-world test site.
Two scenarios were modeled over 10 years:
1. No groundwater flow → Heat buildup causes system efficiency to crash after year 1
2. Realistic groundwater flow (matching site conditions) → Heat is swept away, system performs beautifully for 10+ years
The conclusion? With Oahu’s natural groundwater movement, a closed-loop geothermal heat pump system at the Stan Sheriff Center could slash cooling electricity use by 40–60% and pay for itself through energy savings, especially with low-interest financing.
Open-Loop vs Closed-Loop Geothermal Systems in Hawaii
Because Hawaii law protects groundwater quality so strictly, closed-loop systems are likely to dominate future installations.
Economic & Environmental Wins
Reduces peak electricity demand → helps avoid blackouts and expensive new power plants
Cuts cooling bills for schools, military bases, hotels, and office buildings
Zero direct emissions at the building
Uses stable ground temperatures (around 74–76 °F year-round in Honolulu) instead of 90 °F+ outdoor air
Eligible for federal ITC (Investment Tax Credit) 30%+, Hawaii state incentives, and USDA REAP grants
Nicole Lautze, director of UHM’s Hawaii Groundwater and Geothermal Resources Center, summed it up:
“This ETIPP project laid the foundation for what I hope will be additional funding to install actual geothermal cooling systems on the UH campus and across the state.”
The Future of Geothermal Cooling in the Aloha State
The report ends with a clear roadmap:
1. Prioritize large public and DoD buildings in high-favorability zones
2. Pursue demonstration projects at UH Mānoa and select schools
3. Explore seawater district cooling (already proven at NELHA on Big Island) as complementary technology
4. Secure low-interest loans and grants to offset upfront costs
With electricity rates in Hawaii still among the highest in the nation, geothermal heat pumps aren’t just “green” , they’re an economic necessity.
Want to See If Your Property Is in a High-Favorability Zone?
The full report (including interactive GIS favorability maps) is now publicly available through the Hawaii Groundwater and Geothermal Resources Center and Lawrence Berkeley National Laboratory websites.
If you own or manage a commercial property, a school, a hotel, or a military facility on Oahu, now is the time to investigate geothermal cooling. The geology is ready. The technology is proven. And the new 2025 report just proved Hawaii has some of the best conditions on the planet.
Contact:
Hawaii Groundwater & Geothermal Resources Center – hgg.rc@hawaii.edu
or visit the ETIPP project page for the complete 2025 Hawaii Geothermal Cooling Feasibility Report.
Aloha, cooler buildings, and lower electric bills are closer than you think , they’re right beneath our feet.
Source:Clean Energy Technica
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