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New Report Illuminates Geothermal Cooling Potential in Hawaii – CleanTechnica

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New Report Illuminates Geothermal Cooling Potential in Hawaii – CleanTechnica



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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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Hawaii County accepting applications for Summer Fun employees

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Hawaii County accepting applications for Summer Fun employees


HAWAII ISLAND (HawaiiNewsNow) – The County of Hawaii Department of Parks and Recreation is now accepting applications for temporary positions in its 2026 Summer Fun program.

The two positions available are Activity Aide I ($17.50 per hour) and Activity Aide II ($19 per hour).

To be considered for employment, applicants must possess a valid first-aid certification, attend mandatory training June 2–5, and be available to work June 8–July 17.

Applications are available online on the Parks and Recreation website, and must be submitted to the Recreation Division Office at 799 Pi‘ilani St., Hilo, HI 96720, postmarked by Saturday, Feb. 28.

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For more information, call the Recreation Division Office at (808) 961-8740.



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Hawaii’s jobless rate remains second lowest in U.S. – Hawaii Tribune-Herald

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Hawaii’s jobless rate remains second lowest in U.S. – Hawaii Tribune-Herald






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Healthier Hawaii: How to protect your hearing; head and neck warning signs you shouldn’t ignore

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Healthier Hawaii: How to protect your hearing; head and neck warning signs you shouldn’t ignore


HONOLULU (HawaiiNewsNow) – You may have received new earbuds or headphones during the holidays. But there are a few things you keep in mind when it comes to protecting your hearing.

Dr. Ross Shockley, an otolaryngologist with Wilcox Medical Center and Kaua‘i Medical Clinic, offers the following tips for hearing, as well as head and neck health.

Head and neck cancers

Many people are not familiar with head or neck cancers. What causes it and when should someone see a doctor?

  • Traditionally, head and neck cancers were mostly associated with longtime smokers and drinkers. Now, more cases are tied to human papillomavirus (HPV), even in nonsmokers and drinkers. HPV is the same virus that can lead to cervical cancer in women. It is common and can have no symptoms.
  • If you have throat pain, pain when swallowing that doesn’t go away, or a mass in your neck that feels firm and isn’t moving, don’t wait. See your doctor.
  • Head and neck cancers can be treated, no matter the cause, if caught early.

How to prevent hearing loss

More young adults, in their early 20s, are experiencing hearing loss. Can hearing loss be reversed?

  • Hearing loss can’t be reversed. Once ringing in ears starts, that can be permanent.
  • Wear appropriate hearing protection when using power tools or firing weapons.
  • You can find ear protection that blocks out sound for about $15. Protection that covers the whole ear are better than earplugs.

How do you know if music or movies are too loud?

  • Don’t turn anything up to the maximum.
  • You want the volume to be at the lowest level where you can still hear and understand.
  • If there is background noise, don’t crank up the volume all the way to fight it. Use noise-cancelling headphones or go somewhere quieter.

Dangers of cleaning your ears

You may feel the urge to clean your ears. Shockley says do less, or even nothing at all.

  • Our ears clean themselves. As new skin grows, it takes wax with it out of your ear.
  • When you clean your ears, you’re interrupting that natural cleaning process.
  • You can also put yourself at risk for external ear infections – or make your ears itch more.



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