Puna Geothermal Venture

Last updated

Puna Geothermal Venture
Puna Geothermal plant.webp
Puna Geothermal Venture
CountryUnited States
Location Puna, Hawaii
Coordinates 19°28′43″N154°53′20″W / 19.4785°N 154.8888°W / 19.4785; -154.8888
StatusOperational
Construction began1989
Commission date 1993
Owner(s) Ormat Technologies
Geothermal power station
Type Binary cycle
Wells11
Max. well depth8,297 feet (2,529 m)
Combined cycle?Yes
Power generation
Nameplate capacity 38 MW
External links
Website hawaiianelectric.com/clean-energy-hawaii/clean-energy-facts/renewable-energy-sources/geothermal/puna-geothermal-venture-(pgv)
Commons Related media on Commons

The Puna Geothermal Venture (PGV) is a geothermal energy power plant on the island of Hawaii, the largest island in the state of Hawaii. The plant was shut down shortly after the start of the May 2018 lower Puna eruption, and resumed power generation in November 2020. [1] The eruption had caused lava to flow over a PGV power substation, a warehouse and at least three geothermal wells that had been preventatively quenched and capped when lava fountains erupted nearby, eventually also cutting off road access. [2] [3]

Contents

PGV is the first and only commercial geothermal power plant in Hawaii. Constructed on a site adjacent to failed experimental wells drilled and operated by the Hawaii Geothermal Project in the 1970s and 80s, construction on the generating facility began in 1989 and was completed in 1993.

Prior to the lava damage, the plant had an installed generating capacity of 38 MW [4] from six production wells and five injection wells along Kīlauea’s East rift zone. Its output was sold to Hawaiian Electric Industries (also known as HELCO). [5] The plant generated up to 10% of the island’s electrical energy as of 2018. [6]

History

Early exploration and development

The first exploratory geothermal wells in Kapoho were drilled in 1961–62. [7] :9 The effort was spearheaded by local landowner Richard Lyman following a trip to Japan, where he learned of a project to lay underwater power cables between the country's islands. Upon returning to Hawaii, Lyman promoted geothermal power generation in Puna, distributed to Oahu and other population centers by underwater cables, as a way of developing the economy. He found business partners to establish Hawaii Magma Power in 1961. Exploratory wells were drilled before the company validated their insufficient potential, although Lyman claimed to the Honolulu Advertiser that the company "had mechanical difficulties and gave up." [8] :12–13

Hawaii Geothermal Project

In the 1970s, the Hawaii Geothermal Project was formed to conduct federal and state-funded research. [8] :13–15 After studies of the geology and geothermal potential of the area were completed, a site for the first well was chosen in 1975. Drilling began without environmental impact studies or a period for public input. At the time, the area around the drill site was rural and undisturbed, but subdivisions were planned nearby. [8] :14–15 The well was occasionally allowed to discharge gas and fluid from the borehole, which created a loud noise and release pollutants into the air. By 1976, three subdivisions nearby had been established and were beginning to house residents, including twelve families who lived within one mile of the well. The continued noise pollution and toxic gas discharges began to cause concern and opposition from the residents. Funds were secured from the federal and state governments to turn the well's geothermal energy into electricity. [8] :15–19 Although HELCO was among the project stakeholders, they assured stockholders that they would not invest the company's capital in the project due to the volcanic and seismic risk at the site. [8] :19

An experimental 3 MW generator was completed in 1981 and remained operational throughout the 1980s. However, families continued to build and move into the nearby subdivisions, resulting in several attempts and a failed lawsuit to stop the noise and pollution. [8] :20–29 Since the site was within a lava hazard zone, the generator was built on skids and housed in a building which included a crane so that the generator could be removed if lava flows threatened the facility. Additionally, the wellhead was housed in a concrete bunker that could be sealed to prevent lava from damaging the wellhead. [9] :13 Despite the opposition and the operating losses incurred by operating and maintaining the generator, there was enough support to keep the generator operating. In April 1989, county officials raised concerns about the condition of the facility following a minor blowout and considered reviewing and possibly revoking the operating permit for the site. After several additional incidents at the site in 1989, the facility was ordered to shut, which occurred on December 11. [8] :30–32 During its life, the HGP generator produced between 15 and 19 million kilowatt hours of electricity annually. [9] :13

Puna Geothermal Venture

Puna Geothermal Venture
Invisible Square.svg
Invisible Square.svg
Mapscaleline.svg
4km
2.5miles
Black pog.svg
Leilani Estates
Red pog.svg
Puna Geothermal Venture

In 1980, HELCO requested a proposal for 25 MW of geothermal electricity generation. A joint venture was formed that year between two of Lyman's companies and two other companies to produce geothermal energy on a 500-acre (200 ha) parcel leased from the Lyman family. The joint venture was renamed Puna Geothermal Venture in 1981. Over the following years, PGV drilled three wells, but all suffered from well casing mechanical failures and were unusable. [8] :39–41

In 1986, PGV secured a contract with HELCO to supply 25 MW of electricity by 1993. PGV promised that they would adopt technology that would result in zero emissions and operate at a drastically lower noise level. In 1989, when the HGP facility was facing growing problems, the PGV proposed facility managed to overcome enough local opposition to be granted a permit from the local planning commission. [8] :41–45

The plant raised local concerns as a result of occasional toxic emissions. [10] In 1991, well KS-8 suffered a blowout, causing the state to suspend the permits for the plant. [11] [12] In 2016 the plant's owners were found to be in violation of U.S. Environmental Protection Agency standards regarding hydrogen sulfide releases and was fined $76,500 for two incidents in 2013. [13] [14] Additional concerns and opposition to the plant were raised by Native Hawaiians, who viewed all forms of volcanic activity as demigod Pele manifestations. They declared geothermal wells and energy production to be a desecration. [7] :7

In 2005 during the drilling of the KS-13 well, magma was encountered at a depth of 8,163 ft (2,488 m). The borehole had to be redrilled several times as the magma flowed up the borehole, cooling into clear, colorless glass. The magma, at a temperature of approximately 1922 °F (1050 °C), was dacitic—similar to the granitic rock that forms continents—consisting of approximately two-thirds silica, which contrasts with the dark, iron-rich basaltic rock that forms most of the Hawaiian Islands. It was encountered after drilling through a 240 ft (73 m) layer of diorite igneous rock, which suggested to researchers that the magma had chemically separated as it dwelled for a long period. [15] [16] [17] [18] As quoted in Nature , the team said it was possibly the first time that "the actual process of differentiation of continental-type rock from primitive ocean basalt has been observed in situ". [15] Magma specialist Bruce Marsh of Johns Hopkins University described the uniqueness of the encounter: "Before, all we had to deal with were lava flows; but they are the end of a magma's life. They're lying there on the surface, they've de-gassed. It's not the natural habitat. It's the difference between looking at dinosaur bones in a museum and seeing a real, living dinosaur roaming out in the field." [18]

PGV had a generating capacity of 25 MW when it opened in 1993, growing to 30 MW in 1995 and 38 MW in 2012. [7] :9 In 2015, HELCO announced that Ormat was the winner of a bid to add 25 MW of geothermal generating capacity in the Puna district. [19] [10] [7] :25 In March 2018, Ormat announced their plan to increase production at the plant by 8 MW—from 38 MW to 46 MW—by 2020. [20]

Lava damage and closure in 2018

Red circle.svg
USGS Kilauea multimediaFile-2079.jpg
Southern part of the Puna Geothermal Venture (red circle) is seen nearby the lava fountains of Kīlauea volcano

On May 3, 2018 earth fissures opened inside and around the Leilani Estates subdivision near the PGV plant, following hundreds of earthquakes over the first two days of May. Concerns of possible toxic hydrogen sulfide gas releases and explosions at the geothermal power facility led to preemptive equipment shutdowns and inventorying its stockpile of highly-flammable pentane. Earthquake frequency began increasing and the first cracks appeared in Leilani Estates on May 1–2; the plant was taken off-line approximately three hours after it received the first report that lava had begun to flow on May 3. [21] All pentane stored at PGV, approximately 60,000 US gallons (230,000 L; 50,000 imp gal), was removed by the morning of May 10. [22]

Over the following weeks, the wells were stabilized with cold water—the weight of the water was sufficient to prevent steam from rising—and allow them to be plugged. One well, KS-14, possibly super-heated from close proximity to magma, could not be quenched and was filled with drilling mud in an attempt to stabilize it. The wells were then sealed with metallic plugs, which arrived at the site on May 22, that PGV officials claimed could withstand 2000 °F (1100 °C) lava. [23] [24] [25] [26] [27] [28] Tom Travis of the Hawaii Emergency Management Agency, claimed that he researched and was unable to find any precedent for lava overrunning a geothermal well that had been shut down like the wells at PGV. The PGV team had spoken with scientists in Iceland who have operated wells within lava fields and provided insights into how lava might affect the wellhead. [28] :8:03–9:26

Lava approached several of the capped wells on May 27. [2] Capped KS-5 and KS-6 wells were inundated by the lava from fissures 7 and 21 on May 27 and 28. [29] [30] The event was the first time lava had covered a geothermal well. [31] [32] On May 30 a substation and a warehouse containing a drilling rig were overrun and destroyed by molten rock, cutting the main access road to the facility. [33] A third well was inundated thereafter. [3]

Despite the shutdown, Hawaii Electric Light did not expect blackouts on the Big Island to be caused by insufficient power generation as older, diesel-fueled generators were brought on-line. [34] [35] [25]

2020 restart and 2022 proposed expansion

Work began on drilling in late 2019. [36] The plant resumed reduced operations in November 2020. [1]

As of early 2022, the Puna Geothermal Venture power plant was reported to be producing approximately 25.7 MW of electric power for the Big Island.

In July 2022 it was announced that an expansion of PGV's power output was proposed. [37] The plan, called the Repower Project, has a goal of 46 MW in Phase 1 and then to 60 MW in Phase 2, and would implement the increase in power generation by replacing 12 operating power-generating units with as many as four upgraded power-generating units, operating on the existing grounds of the current facility.

PGV published an Environmental Impact Statement Preparation Notice on the July 23, 2022 edition of “The Environmental Notice”. [38] In February 2024, it was announced that a new power purchase agreement was obtained, allowing a maximum of 46 MW and a minimum of 30 MW. This would be achieved by replacing old units with three new units within three years. [39]

Kapoho Geothermal Reservoir

PGV is located in the East Rift Zone of the Kīlauea volcano, which forms Hawaii Island. The geothermal energy reservoir there is known as the Kapoho Geothermal Reservoir. [9] :11 The geothermal energy potential of the East Rift Zone is estimated to exceed 200 MW. [40] The geothermal reservoir is contained within basaltic rock and relies on the permeability of two major fracture systems. Both fracture systems have large openings, recorded by the drop of 8.5 in (220 mm) drillbits for up to 30 ft (9.1 m). [41]

Facilities

Puna Geothermal Venture
Invisible Square.svg
Invisible Square.svg
Mapscaleline.svg
200m
220yds
Red circle (thin).svg
Pad A
Red circle (thin).svg
Pad B
Green pog.svg
Binary cycle plant
Green pog.svg
Combined cycle plant
Red circle (thin).svg
Pad F
Red circle (thin).svg
Pad E
Red circle (thin).svg
Pad D
Location of plants and well pads [7] [42]

The plant is owned by Ormat Technologies which purchased it in 2004. [43]

Power plants

Two power plants operate in the Puna Complex. The first plant consists of ten Combined cycle Ormat Energy Converters (OEC) made up of ten steam turbines and ten binary turbines and opened in 1993. [44] The second plant consists of two Binary cycle OECs that entered service in 2011 and commenced commercial operation in 2012.

Wells

As of December 2017, six production wells and five injection wells made up the Puna Complex. [44]

List of wells as of September 2014 [45]
WellWellfieldTypeDepthStatus after 2018 eruption
Kapoho State 1A (KS-1A)Pad A Injection
Kapoho State 3 (KS-3)Pad EInjection
Kapoho State 5 (KS-5)Pad EProductionCovered by lava
Kapoho State 6 (KS-6)Pad EProduction6,532 feet (1,991 m)Covered by lava
Kapoho State 9 (KS-9)Pad AProduction
Kapoho State 10 (KS-10)Pad AProduction5,210 feet (1,590 m)
Kapoho State 11 (KS-11)Pad AInjection6,500 feet (2,000 m)
Kapoho State 13 (KS-13)Pad AInjection8,297 feet (2,529 m)
Kapoho State 14 (KS-14)Pad EProductionIn proximity to magma
Kapoho State 15 (KS-15)Pad BInjection
Kapoho State 16 (KS-16)Pad AProduction
Kapoho State 17 (KS-17)Pad EProduction

As of 2008, the five active production wells had a surface elevation of 620 ft (190 m) above sea level and produce a mixture of steam and brine. The five wells produced an average of 600,000 lb/hour (270,000 kg/hour) of steam and 1,200,000 lb/hour (545,000 kg/hour) of brine. The temperature of fluids emerging from the production wells is approximately 640 °F (338 °C), which is returned to the injection wells at approximately 300–400 °F (150–200 °C). [41] [46]

Alternative uses of geothermally-heated fluids

In addition to electricity generation, additional uses of the facility have been suggested. Andrea Gill of the Hawaii Department of Business, Economic Development, and Tourism—on behalf of a working group established to consider direct uses of the geothermal energy at PGV and its vicinity—outlined potential direct uses of the fluids as well as shallow groundwater wells in its vicinity, including fruit and macadamia nut dehydration, aquaculture and greenhouse heating, pasteurization and sterilization, geothermal/health spas, and geothermal heat pumps. [46] At PGV, hot brine after being utilized to generate electricity is approximately 300–400 °F (150–200 °C) when it is reinjected; the brine could be tapped for its thermal energy before reinjection. Water wells under 750 ft (230 m) in the vicinity of PGV have recorded temperatures up to 193 °F (89 °C). [46]

In 2005, after a drill hit an uncommonly-observed type of magma, researchers and PGV expressed a desire to turn the borehole into an observatory for scientific studies. [15]

Related Research Articles

<span class="mw-page-title-main">Kīlauea</span> Active volcano in Hawaii

Kīlauea is an active shield volcano in the Hawaiian Islands. It is located along the southeastern shore of Hawaii Island. The volcano is between 210,000 and 280,000 years old and grew above sea level about 100,000 years ago. Since the islands were settled, it has been the most active of the five volcanoes that together form the island and among the most active volcanoes on Earth. The most recent eruption occurred on June 3, 2024, along fissures that opened on the volcano's southwest rift zone.

<span class="mw-page-title-main">Kalapana, Hawaii</span> Town in Hawaii, United States

Kalapana is a town and a region in the Puna District on the Island of Hawaiʻi in the Hawaiian Islands. The town was the original location of the Star of the Sea Painted Church.

<span class="mw-page-title-main">Puna, Hawaii</span> District of Hawaiʻi County, Hawaii

Puna is one of the 9 districts of Hawaii County on the Island of Hawaiʻi. It is located on the windward side of the island and shares borders with South Hilo district in the north and Kaʻū district in the west. With a size of just under 320,000 acres (1,300 km2) or 500 sq. miles, Puna is slightly smaller than the island of Kauaʻi.

<span class="mw-page-title-main">Geothermal energy in the United States</span> Overview of geothermal power in the United States of America

Geothermal energy in the United States was first used for electric power production in 1960. The Geysers in Sonoma and Lake counties, California was developed into what is now the largest geothermal steam electrical plant in the world, at 1,517 megawatts. Other geothermal steam fields are known in the western United States and Alaska. Geothermally generated electric power can be dispatchable to follow the demands of changing loads. Environmental impact of this energy source includes hydrogen sulfide emissions, corrosive or saline chemicals discharged in waste water, possible seismic effects from water injection into rock formations, waste heat and noise.

<span class="mw-page-title-main">Kawerau Power Station</span>

The Kawerau Power Station is a 100-megawatt geothermal power plant located just outside the town of Kawerau in the Bay of Plenty Region of New Zealand. The power station is situated within the Kawerau geothermal field, which is part of the Taupo Volcanic Zone. Completed in July 2008 by Mighty River Power at a cost of NZ$300 million, the plant's capacity proved greater than expected. The station is the largest single-generator geothermal plant in New Zealand.

<span class="mw-page-title-main">The Geysers</span> Worlds largest geothermal field, California

The Geysers is the world's largest geothermal field, containing a complex of 18 geothermal power plants, drawing steam from more than 350 wells, located in the Mayacamas Mountains approximately 72 miles (116 km) north of San Francisco, California.

<span class="mw-page-title-main">Geothermal power</span> Power generated by geothermal energy

Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries.

<span class="mw-page-title-main">Wao Kele o Puna</span> A lowland wet forest in Hawaii

Wao Kele O Puna is Hawaiʻi's largest remaining lowland wet forest, about 15 mi (24 km) south of the city of Hilo, along the East Rift Zone of Kīlauea volcano on the Island of Hawaiʻi. The name means the upland rainforest of Puna. Puna is one of 9 districts on the island. Lava from Kīlauea continues to flow onto forest land.

<span class="mw-page-title-main">Svartsengi power station</span> Geothermal power station in Iceland

Svartsengi power station is a geothermal power plant, which is located in the Svartsengi geothermal field, about 4 kilometres (2.5 mi) north of Grindavík, approximately 20 km (12 mi) SE of Keflavík International Airport and 45 km (28 mi) from Reykjavík. The electric power station was built in 1976 by HS Orka. It was the world's first combined geothermal power plant for electric power generation and hot water production for district heating.

<span class="mw-page-title-main">Ormat Technologies</span>

Ormat Technologies, Inc. is an international company based in Reno, Nevada, United States. Ormat supplies alternative and renewable geothermal energy technology. The company has built over 190 power plants and installed over 3,200 MW. As of January 2021 it owns and operates 933 MW of geothermal and recovered energy based power plants. Ormat has supplied over 1000 turbochargers worldwide: North America, South America, Europe, Australia, and Asia. The company's products also include turbines, generators, and heat exchangers.

<span class="mw-page-title-main">Olkaria</span> Geothermal region in Kenya

The Olkaria Area is a region located immediately to the south of Lake Naivasha in the Great Rift Valley of Kenya, Africa. It is geothermally active and is being used to generate clean electric power. The region has an estimated potential of 2,000 MW. This is almost double the maximum daily electricity peak demand recorded in 2008/2009 for the entire country.

<span class="mw-page-title-main">Energy in Hawaii</span> Overview of energy resources in Hawaii, US

Energy in the U.S. state of Hawaii is produced from a mixture of fossil fuel and renewable resources. Producing energy is complicated by the state's isolated location and lack of fossil fuel resources. The state relies heavily on imports of petroleum. Hawaii has the highest share of petroleum use in the United States, with about 62% of electricity coming from oil in 2017. As of 2021 renewable energy made up 34.5% on Oahu, Maui and the island of Hawaii.

<span class="mw-page-title-main">U.S. Geothermal</span>

U.S. Geothermal, Inc. was an independent geothermal energy company focused on the development, production and sale of electricity from geothermal energy, until its acquisition by Ormat Technologies in January 2018. The company operates three geothermal plants in the United States. located in Idaho, Oregon and Nevada, and is developing power plants in California, Nevada, Oregon as well as in Central America in the Republic of Guatemala.

Top Energy Limited is an electricity distribution and generation company based in Kerikeri, New Zealand. It owns and manages the electricity lines network in the Far North District of New Zealand, including Kaitaia, Kerikeri and Kaikohe. The service area covers 6,822 km2 and serves over 32,000 customers. It also owns and operates the Ngāwhā Geothermal Power Station.

<span class="mw-page-title-main">2018 Hawaii earthquake</span> 6.9-magnitude earthquake in Hawaii

On May 4, 2018, an earthquake with a magnitude of Mw 6.9 struck Hawaii island in the Hawaii archipelago at around 12:33 p.m. local time. The earthquake's epicenter was near the south flank of Kīlauea, which has been the site of seismic and volcanic activity since late April of that year. According to the United States Geological Survey the quake was related to the new lava outbreaks at the volcano, and it resulted in the Hilina Slump moving about two feet. It was the largest earthquake to affect Hawaii since the 1975 earthquake, which affected the same region, killing two people and injuring another 28.

<span class="mw-page-title-main">2018 lower Puna eruption</span> Volcanic eruption on Hawaiʻi Island

The 2018 lower Puna eruption was a volcanic event on the island of Hawaiʻi, on Kīlauea volcano's East Rift Zone that began on May 3, 2018. It is related to the larger eruption of Kīlauea that began on January 3, 1983, though some volcanologists and USGS scientists have discussed whether to classify it as a new eruption. Outbreaks of lava fountains up to 300 feet (90 m) high, lava flows, and volcanic gas in the Leilani Estates subdivision were preceded by earthquakes and ground deformation that created cracks in the roads.

<span class="mw-page-title-main">Mammoth Geothermal Complex</span>

The Mammoth Geothermal Complex is a complex of 4 geothermal power stations located at Casa Diablo Hot Springs about 3 miles (4.8 km) east of Mammoth Lakes, California. The complex is owned by Ormat and operated by its subsidiary Mammoth Pacific.

References

  1. 1 2 "Puna Geothermal Venture Goes Back Online". Big Island Video News. November 12, 2020.
  2. 1 2 "Lava speeds up, forcing evacuations and covering well at Puna Geothermal plant". Star Advertiser . May 27, 2018.
  3. 1 2 "Puna Geothermal Venture faces challenges amid uncertainty". Star Advertiser . July 8, 2018.
  4. "Renewable Energy & Storage Projects". www.hawaiianelectric.com.
  5. "Puna Geothermal Venture (PGV)". www.hawaiianelectric.com.
  6. "Hawaii Electricity Profile Analysis". U.S. EIA. Retrieved February 3, 2021.
  7. 1 2 3 4 5 Schroeder, Martin (May 27, 2016). "A Renewable Energy Solution on Hawaii Island – The Puna Geothermal Plant" (PDF). Ormat Technologies. Retrieved May 30, 2018.
  8. 1 2 3 4 5 6 7 8 9 Szvetecz, Annie (August 2001). Geothermal energy in Hawai'i: an analysis of promotion and regulation (PDF) (MSc thesis). ProQuest LLC. Retrieved May 30, 2018.
  9. 1 2 3 Boyd, Tonya L.; Thomas, D.; Gill, A. T. (September 2002). "Hawaii and Geothermal-What Has Been Happening" (PDF). Geo-Heat Center Quarterly Bulletin. 23 (3): 11–21. Retrieved June 14, 2018.
  10. 1 2 Hunt, Tam (March 20, 2015). "Is Going Bigger on Geothermal a Good Move for the Big Island?". Greentech Media. Retrieved May 30, 2018.
  11. "At Puna Geothermal Venture, Success Is Always Just Around the Corner". www.environment-hawaii.org.
  12. Essoyan, Susan (June 15, 1991). "Blowout Shuts Geothermal Unit in Hawaii". Los Angeles Times. Retrieved June 9, 2018.
  13. "EPA finds Puna Geothermal Venture violated chemical safety rules". KHON2 . Nexstar Media Group. January 12, 2016.
  14. Higuchi, Dean (January 12, 2016). "EPA finds Puna Geothermal Venture violated chemical safety rules" (Press release). Honolulu: EPA. Retrieved May 30, 2018.
  15. 1 2 3 Dalton, Rex (December 17, 2008). "Drillers hit Hawaiian magma". Nature . doi:10.1038/news.2008.1317 . Retrieved June 2, 2018.
  16. "Abstract: Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii". American Geophysical Union. Retrieved June 2, 2018.
  17. "Abstract:Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii". ResearchGate. Retrieved June 2, 2018.
  18. 1 2 Amos, Jonathan (December 17, 2008). "Drillers break into magma chamber". BBC News . Retrieved June 2, 2018.
  19. Cocke, Sophie (February 24, 2015). "Ormat Awarded Big Island Geothermal Contract". Honolulu City Beat. Retrieved May 30, 2018.
  20. Kim, Alice (March 17, 2018). "Puna Geothermal Venture Increasing Production". Hawai'i Groundwater & Geothermal Resources Center. Retrieved May 30, 2018.
  21. "VIDEO: Puna Geothermal Concerns At Eruption Meeting". Big Island Video News. May 5, 2018. Retrieved May 30, 2018.
  22. "Crews remove pentane gas from Puna geothermal plant amid safety concerns". Hawaii News Now. May 8, 2018. Retrieved May 30, 2018.
  23. "Wells are hurriedly plugged at Hawaii power plant under threat of lava flow". Los Angeles Times. AP. May 23, 2018. Retrieved May 30, 2018.
  24. Burnett, John (May 21, 2018). "Official: As lava approaches, workers close to capping geothermal wells". Hawaii Tribune Herald. Retrieved May 30, 2018.
  25. 1 2 "Puna Geothermal Venture deemed stable after lava covers two wells". KHON. May 28, 2018. Retrieved May 30, 2018.
  26. "State says well field at Puna Geothermal 'essentially safe'". Hawaii News Now. May 21, 2018. Retrieved May 30, 2018.
  27. "VIDEO: As Lava Nears, Officials Working To Kill Geothermal Wells". Big Island Video News. May 21, 2018. Retrieved May 30, 2018.
  28. 1 2 Tom Travis (May 21, 2018). As Lava Nears, Officials Working To Kill Geothermal Wells (May 21, 2018) (Press conference recording). Big Island Video News. Retrieved May 21, 2018.
  29. Lincoln, Mileka. "Lava covers at least 1 well at Puna geothermal plant; governor says risk is 'mitigated'". Hawaii News Now .
  30. "Some Leilani Estates residents ordered to evacuate immediately". Hawaii Tribune-Herald .
  31. Rosa, Jolyn. "Lava covers potentially explosive well at Hawaii geothermal plant". Reuters. Retrieved May 28, 2018.
  32. Burnett, John (May 28, 2018). "Lava takes 10 homes, covers another geothermal well". Hawaii Tribune-Herald . Retrieved May 29, 2018.
  33. "Lava burns 2 buildings at Puna Geothermal plant". Honolulu Star-Advertiser. The Associated Press. June 2, 2018.
  34. Proctor, Darrell (May 23, 2018). "Officials Say No Risk of Blackout From Lava Breach at Hawaii Geothermal Plant". Power Magazine.
  35. "Hawaii Electric Light expects sufficient power even with geothermal plant shut do" (Press release). Hawaii Electric Light. May 3, 2018. Retrieved May 30, 2018.
  36. Daysog, Rick (October 10, 2019). "Puna Geothermal Venture to drill new well as it prepares to resume operations". Hawaii News Now.
  37. "5 years after lava nearly destroyed it, Puna Geothermal announces expansion plans". Hawaii News Now. May 9, 2023. Retrieved May 9, 2023.
  38. "Puna geothermal site in Hawaii to expand capacity with Repower project". thinkgeoenergy.com.
  39. Ormat receives PPA for expanded geothermal capacity at Puna, Hawaii, ThinkGeoEnergy, Carlo Cariaga, 12 February 2024
  40. "Geothermal Technologies Program: Tapping the Earth's energy to meet our heat and power needs" (PDF). U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. April 2004. Retrieved June 2, 2018.
  41. 1 2 Fitch, David; Matlick, Skip (2008). "Gold, silver and Other Metals in scale— Puna Geothermal Venture, Hawaii" (PDF). GRC Transactions. 32: 385–388. Retrieved June 2, 2018.
  42. "Puna Geothermal Venture". Hamilton Library, University of Hawai'i at Manoa.
  43. "Puna Geothermal Venture - Hawai'i Groundwater & Geothermal Resources Center". www.higp.hawaii.edu.
  44. 1 2 "2017 Annual report" (PDF). Ormat Technologies.
  45. "Noncovered Source Permit Review Summary (Renewal)" (PDF). health.hawaii.gov.
  46. 1 2 3 Gill, Andrea T. (2004). "Prospective Direct Use Enterprises in Kapoho, Hawaii" (PDF). Hawaii Dept. of Business, Economic Development and Tourism, Strategic Industries Division. Retrieved June 2, 2018.