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University of Hawaii at Manoa and Lawrence Berkeley National Laboratory Teamed up To Analyze Feasibility of Geothermal Cooling Technologies
By Justin Daugherty, NLR
In areas with geologically recent volcanic activity and ample underground water flow, like the Hawaiian Islands, geothermal energy technologies present options to augment the electric grid.
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Oahu’s steep terrain and highly permeable volcanic rock enable large groundwater flow, a must for successful ground heat exchangers in Hawaii, where load is cooling dominated. Shown here is Kaena Point, the western tip of Oahu’s North Shore. Photo from Christine Doughty, Lawrence Berkeley National Laboratory.
To investigate building cooling and energy efficiency options, the University of Hawaii at Manoa’s Hawaii Groundwater and Geothermal Resources Center collaborated with scientists at Lawrence Berkeley National Laboratory through the U.S. Department of Energy’s Energy Technology Innovation Partnership Project (ETIPP).
Managed by the National Laboratory of the Rockies (NLR), formerly known as NREL, ETIPP supports remote, coastal, and island communities with technical assistance and energy planning to help them build more reliable and affordable energy systems. Communities apply for up to 24 months of technical assistance, and those communities drive the scopes and focuses of their energy projects.
University of Hawaii at Manoa joined the program in 2022 with a desire to explore geothermal options, and a new report from this project details the feasibility of developing shallow ground heat exchangers (GHEs) across Oahu and at a specific site on the island for cooling.
Geothermal heat pumps take advantage of relatively constant temperatures just under the earth’s surface, using GHEs to exchange heat with the earth. Through a system of looping pipes in the shallow ground, GHEs can move heat from a warm place to a cooler place, like how a refrigerator functions.
“High-temperature geothermal, which requires deep drilling, is required to produce electricity, but low-temperature geothermal such as GHEs, which can be accessed much nearer the ground surface, can be used for building heating and cooling, greatly lessening loads on the electric grid,” said Lawrence Berkeley National Laboratory’s Christine Doughty, staff scientist.
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“I believe both types of geothermal have potential to be an asset to Hawaii,” added Nicole Lautze, founder and director of the Hawaii Groundwater and Geothermal Resources Center.
Determining Geothermal Cooling Favorability in Hawaii
In open-loop geothermal systems, wells are drilled to extract and inject groundwater, allowing the movement of thermal heat to and from the earth. These GHEs use cooler ground water from outside the system for the cooling process and expel the warmer water afterward.
In contrast, closed-loop GHE systems continually circulate a heat-transfer solution through pipes, which transfers heat to and from the ground via thermal conduction. Groundwater needs to have temperatures that are low enough to effectively cool buildings, and groundwater flow in a GHE system works to remove built-up heat.
Hawaii has far greater needs for cooling than for heating—meaning that GHEs would add heat to the subsurface and cause the systems to not function as desired. That is where groundwater comes in: It replaces heated water from the boreholes and maintains the functionality of the GHE system. Sufficient groundwater flow, then, is essential to the considerations for GHE deployment. GHE systems may not be deployed in areas with restricted watersheds or where there is subsurface production of freshwater. Therefore, closed-loop systems may be a more reasonable option in some locations.
Left: A geographic information system map of Oahu depicts different soil permeability zones (“Ksat_Class” indicates the potential speed of groundwater flow). Right: Locations of U.S. Department of Defense lands and public and private schools—potential customers for GHE—are shown.
Numerous factors help determine whether a community or business may consider GHEs. Areas with older homes may lack efficient energy systems, and some organizations, like schools or government buildings, may prioritize more adaptive heating and cooling. Cultural considerations are also very important, and a new NLR report incorporates Hawaii communities’ perspectives on geothermal.
Economic factors are another big consideration, with the expense of deploying a system versus energy savings playing into overall cost. Modeling revealed that electricity and energy transfer demand decreased, and such reductions contributed to cost savings. Longer loan terms may help ease deployment expenses for geothermal systems.
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ETIPP researchers factored the above parameters into their analysis to develop favorability maps for closed-loop and open-loop GHE systems. They used specific geographic information system layers with 11 attributes—including elevation, geology, and soil permeability—to develop an overall favorability map for GHEs on Oahu.
For the site-specific feasibility analysis at the University of Hawaii at Manoa’s Stan Sheriff Center, researchers used a hydrogeologic model to analyze groundwater flow of a closed-loop system at the site. Restrictions on water quality—mandating that groundwater must be left in its natural state—diminished the available area for GHE system deployment across the island, while many coastal areas showed high favorability. Overlays showing potential customers and restricted areas sharpened the maps.
This closed-loop favorability map shows restricted areas where GHE development is not possible. Pixels colored dark green—the top of the color spectrum table—indicate land that is more favorable to geothermal energy.
Geothermal Cooling Potential at University of Hawaii at Manoa
From the island-wide analysis, ETIPP analysis homed in and found that the Stan Sheriff Center at the University of Hawaii at Manoa, a building with a high cooling load in an area with lots of open space surrounding it, could make a good candidate for site-specific analysis of GHE technology.
Researchers used a hydrogeologic model to analyze a potential closed-loop system at the site. They modeled groundwater and heat flow, analyzed subsurface heat flow, and completed a techno-economic analysis.
Analysis without groundwater flow showed that the GHE system may operate normally in the first year, but heat buildup would increase water temperatures significantly after that, and without groundwater to sweep heat away, there would be increased chiller demand in years two through six. Modeling that incorporated groundwater flow—with similar conditions as the Stan Sheriff Center—showed that heat would be effectively swept away from the borefield, which would enable successful GHE operation for at least 10 years. Thus, including groundwater in analysis and planning—coupled with low interest loan rates and high capital investment—may provide economic benefits to the university.
The Stan Sheriff Center (white dome in the center of the image) is located at the base of the Koolau Range. Image from Google Earth.
Cold seawater may be an option for cooling-source systems, the analysis concluded, and such a system already operates at the Natural Energy Laboratory of Hawaii. The report authors encouraged further study.
As in Hawaii, ETIPP continues to help communities explore geothermal and other technologies to help meet their energy needs through in-depth, collaborative investigation of potential solutions.
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“This ETIPP project established a strong collaboration with LBNL and the foundation for what I hope is additional grant funding to explore the potential of GHEs on the UHM campus and across the state to cool buildings and reduce load on Hawaii’s grid,” Lautze said.
The U.S. Department of Energy’s Energy Technology Innovation Partnership Project (ETIPP) is a community-led technical support program for coastal, remote, and island communities to access unique solutions and increase energy reliability. By uniting federal agencies, national laboratories, regional organizations, and community stakeholders, ETIPP provides tailored technical support to help communities achieve affordable, reliable solutions to their energy system challenges. This collaborative model leverages the combined expertise and resources of its partners to deliver comprehensive, practical solutions that align with local needs. Learn more about ETIPP.
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Authorities in Hawaii have charged a 36-year-old man with murder in the killings of three people in a remote community known for its eclectic, communal lifestyle.
Jacob Daniel Baker was charged with counts of first- and second-degree murder Saturday, the Hawaii Police Department said in a news release.
Baker remained jailed without bond Sunday and police said his first court appearance was scheduled for Monday. It was not immediately known if Baker had an attorney who could speak for him.
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Charges in the killings came two days after police apprehended Baker following a manhunt on Hawaii’s Big Island, where the three victims were found in the rural Puna community known for its tropical landscape and free-spirited residents.
Robert Shine, 69, was found dead Monday partially submerged in a cement pond, according to police. The second victim, a 79-year-old man, was discovered Tuesday a few hundred feet away. Friends identified him as Chitta Morse.
Police found the third victim, 69-year-old John Carse, late Tuesday at a property 19 miles from where the other two bodies were located.
Police have not given a suspected motive for the killings. Hawaii Police Chief Reed Mahuna has said investigators found no connections among the victims other than that two of them lived near each other.
In addition to the murder charges, Baker also faces counts of burglary, auto theft and criminal damage to property.
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The killings left residents on edge in Puna, a community set amid lush jungle and barren lava fields where people seeking to live off-grid commonly trade work for lodging.
Puna resident Stephen Shaffer said that Baker had worked for his ex-wife, climbing coconut trees on land where she grows fruit, in exchange for a place to live. After several months, Shaffer said, his ex-wife sought a restraining order against Baker, saying she felt threatened by him.
Donald Hyatt, a friend of Shaffer’s ex-wife and of two of the men killed, said Baker left the cabin where he had been living months ago. Hyatt said that Baker recently returned claiming “squatter’s rights” and threatened Shaffer’s ex.
Just days before the killings, two women had requested temporary restraining orders against Baker, saying he had threatened and harassed them, according to court records. A judge denied both applications, saying there was not enough proof of harassment.
Court records showed Baker named in 20 other cases in the past two decades, many of them traffic infractions. In most of those cases, Baker had no attorney and represented himself.
Hawaii is home to a wide range of towns that give older adults relaxing ways to enjoy their retirement years. Across the islands, retirees can find communities with easy access to healthcare and outdoor recreation. Coastal towns like Kailua-Kona and Līhuʻe offer ocean views and nearby medical care. Inland communities such as Waimea and Makawao provide cooler weather and an easier rhythm. Retirees may be drawn to smaller places with a strong community feel, while those wanting more services may prefer regional hubs like Hilo. Together, these Hawaiian towns offer a mix of natural beauty and everyday comforts.
Kailua-Kona
Keauhou Bay, Kailua-Kona, Hawaii.
Kailua-Kona is a coastal town on the Big Island of Hawaii with fewer than 25,000 residents. It continues to attract retirees thanks to its warm weather and ocean access. Areas like Kealakehe and Holualoa are still growing, with new subdivisions adding more housing options for people who want to stay long-term.
Most medical care is provided by the nearby Kona Community Hospital, and clinics throughout the Kona district offer additional services. Some of the main landmarks are Kailua Pier, Huliheʻe Palace, Kamakahonu Beach, and Kona Commons Shopping Center. These spots help residents stay active year-round.
Hilo
Overlooking Hilo, Hawaii.
Hilo is a well-known retirement-friendly community on Hawaii Island, known for being easy to walk around. With about 48,000 residents, according to recent Census data, Hilo is a regional center for healthcare, education, and government services, which helps create long-term stability for residents.
Hilo Benioff Medical Center is the main hospital for East Hawaii and provides most of the area’s healthcare. There are also outpatient and senior care services, such as the nearby Life Care Center of Hilo.
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People in Hilo often spend time at places like Wailoa River State Recreation Area, Hilo Farmers Market, Liliʻuokalani Gardens, and Rainbow Falls. These spots are close to neighborhoods like Waiākea and Keaukaha.
Waimea
Rolling green pastureland with white fences near Waimea, Hawaii’s Big Island.
Waimea is a small inland town on Hawaii Island with fewer than 10,000 residents. Because it sits at a higher elevation, the weather is cooler, with daytime temperatures usually between 70 and 80°F and nights that feel much cooler.
Residents have access to healthcare through local clinics and services linked to Queen’s North Hawai’i Community Hospital in Waimea, which provides essential care for the area. The town has strong connections to Parker Ranch, one of the country’s largest ranches, as well as nearby ranchlands. Waimea attracts retirees who want a quieter inland setting, strong community organizations, and fewer people.
Līhuʻe
A couple walks along Kalapaki Beach in Lihue, Kaua’i, Hawai’i.
Līhuʻe serves as Kauai’s administrative and service center and has fewer than 10,000 residents. The town plays a central role in healthcare and government operations across the island. It is just 30 minutes from Hanapepe and offers retirees a small-town feel, with natural scenery all around.
Wilcox Medical Center is the largest hospital on the island and provides care for residents throughout Kauai. Notable landmarks include Kalapaki Beach, Nawiliwili Harbor, Kauai Museum, and Kilohana Plantation. Together, these sites support recreation, tourism, and community events across the area.
Kapa’a
Shops in downtown Kapa’a in Hawaii. Image credit bluestork via Shutterstock.com
Kapaʻa sits on the east side of Kauai and has about 11,000 residents. It is easy to get around on foot, with everything you could need close by. The town serves as both a place to live and a hub for businesses in the area.
Residents can access healthcare at local clinics such as The Clinic at Kapaa or at Wilcox Medical Center in Līhuʻe. Some well-known spots in Kapaʻa are Kapaʻa Beach Park, the Sleeping Giant Trail, Coconut Marketplace, and Wailua River State Park. Coconut Marketplace has a Farmer’s Market twice a week, plus live local music. Hula classes and shows are also a local favorite offered at Coconut Marketplace.
Kailua
Overlooking Kailua, Oahu.
Kailua is a residential area on the windward side of Oahu with fewer than 50,000 residents. The town is known for its easy access to beaches and well-established neighborhoods such as Enchanted Lake and Coconut Grove.
Residents have access to healthcare through nearby hospitals in the Honolulu area. Adventist Health Castle, which is located in Kailua, is one of the main options. In addition, Kalapawai Market is a local favorite to grab coffee, ube scones, and other treats.
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Kailua is home to many beaches for swimming and watersports, including Kailua Beach Park. Lanikai Beach is a public beach within a residential neighborhood, with no lifeguards, restrooms, or public parking lot. For walking and biking, Kawainui Marsh Wildlife Sanctuary is a popular dog-friendly wildlife sanctuary with a scenic trail.
Haleʻiwa
Aerial view of Haleiwa, Hawaii.
Hale’iwa is known for its slower pace and strong connection to Oahu’s North Shore coastline. This historic North Shore town is said to be the quirkiest and has a population of under 5,000. It maintains a small commercial core while serving nearby rural communities.
Healthcare is available through clinics in Waialua and through The Queen’s Medical Center – Wahiawā in central Oahu.
Notable landmarks in Haleʻiwa include Haleʻiwa Beach Park, a popular spot for fishing and sunset views, and Waimea Bay, known for its large winter surf and summer swimming conditions. The nearby Banzai Pipeline draws surfers from around the world during big-wave season on Oahu’s North Shore. Residents also spend time at Haleʻiwa Aliʻi Beach Park, which has picnic areas and shoreline walking paths.
Wahiawa
Waikele Premium Outlets in Honolulu County, near Wahiawa, Hawaii. Image credit ARTYOORAN via Shutterstock.com
Wahiawa is a central Oahu community with a population of roughly 17,000. It sits between the island’s north and south regions, and provides a quieter inland setting while still allowing access to both Oahu’s north and south coasts.
Healthcare in Wahiawa is available through in-town facilities, such as The Queen’s Medical Center – Wahiawā.
Local landmarks include Lake Wilson, where residents fish and kayak, and the Wahiawa Botanical Garden, known for its large tropical trees and walking paths. Nearby Schofield Barracks remains one of the largest military installations in Hawaii and shapes much of the area’s economy. Residents also rely on Whitmore Village for local businesses, neighborhood services, and access to agricultural areas outside town.
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Makawao
The town of Makawao sits on the slope of the Haleakala volcano in Maui.
Makawao is a small town in upcountry Maui with fewer than 10,000 residents. Its higher elevation gives the area cooler temperatures than much of coastal Maui, especially during the evenings.
Makawao maintains a rural atmosphere while still keeping residents close to shopping and healthcare in nearby Kahului and central Maui for routine and specialized care.
Residents enjoy art galleries, and nearby access routes to Haleakalā National Park, which draw both residents and visitors into Maui’s upland landscapes. The community also gathers around Oskie Rice Event Center, which hosts rodeos and local events throughout the year, while Pukalani Country Club provides golf and recreation with views of central Maui.
Pāhoa
Downtown Pahoa, Hawaii. Image credit Chris Allan via Shutterstock
Pāhoa is a small town on Hawaii Island with fewer than 1,000 residents. The community has a slower pace of life and a strong local character shaped by East Hawaii’s volcanic landscape. Residents access healthcare through clinics in nearby Hilo and facilities connected to Hawaiʻi Health Systems Corporation in East Hawaii.
Local landmarks include Lava Tree State Monument, where lava formations surround walking paths through tropical forest, and the historic downtown which still contains several older storefronts and small local businesses such as Tin Shack Bakery. Nearby Pohoiki Black Sand Beach has become a popular coastal gathering area following recent volcanic activity, while the former Ahalanui Park site (destroyed by the Kīlauea lava flow in 2018) remains an important part of the region’s history and shoreline identity.
Honoka’a
Overlooking Honoka’a, Hawaii.
Honokaʻa is a small plantation-era town on the Big Island of Hawaii. With fewer than 3,000 residents, its historic main street reflects its sugar industry past with preserved storefronts and a compact town center that still serves the surrounding Hamakua Coast communities.
Residents access healthcare through Queen’s North Hawai’i Community Hospital in nearby Waimea, which provides essential services for the region.
Along the main corridor, residents frequent shops such as Tex Drive-In, known for its malasadas, and Cafe Il Mondo, a long-running local café. The nearby Kalōpā State Recreation Area offers forest trails and native vegetation, while the Hamakua Coast provides scenic coastal drives with waterfalls and ocean views. Routes toward Akaka Falls connect the town to one of the island’s most visited natural landmarks.
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Hawaii Retirement Across the Islands
Retirement spots in Hawaii are found across the islands, each with its own pace of life. Towns like Kailua-Kona and Līhuʻe keep residents close to healthcare, services, and coastal scenery, while places such as Waimea, Makawao, and Honokaʻa offer quieter inland settings with strong local character. Others, including Hilo, Kapaʻa, and Haleʻiwa, balance everyday conveniences with beaches, parks, markets, and community gathering places. As people in Hawaii look for more space, fewer crowds, and reliable access to care, these towns show how varied retirement living can be across the state.
HONOLULU (HawaiiNewsNow) – A new optical illusion is taking shape in Kalihi.
Commissioned by Kamehameha Schools, the mural will feature plants and trees native to the area. The artwork aims to highlight how forestry can exist within urban areas.
Coincidentally, the new artwork sits adjacent to one of Kalihi’s most famous murals: Wave 01/101.
The artist Kai’ili Kaulukukui plays with depth and shadow, creating an optical illusion on the flat face of a building.
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“The painting style is called ” trompe-l’œil”, it means ‘trick the eye’,” says Kaulukukui. “It’s been around for 2000 years. They have images of trompe-l’œil style murals at Pompeii, so it’s a very old style.”
Kaulukukui said he’s always been intrigued by the art style, though this is his first time painting it.
“They’re both kind of environmental themed murals,” he said. “This is bringing an image of what a forest could look like in the city. That is like an homage to Pipeline and our beautiful waves that we have here.”
The 55-foot-tall mural is expected to be completed by Sunday, May 31.
After this project, Kaulukukui will start an ocean-themed mural just one street over, bringing a bit more nature into urban Honolulu.
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