Did you know... 20% of the Island of Hawai'i's power comes from geothermal energy?
Located in Puna (Kilauea East Rift Zone), is Hawai’i’s geothermal power plant, Puna Geothermal Venture (PGV). PGV has two air-cooled power plants, a binary system, and a combined cycle system. The plants together generate up to 38 megawatts of electricity. The first plant reached commercial operation in 1993, and the second followed in 2012. PVG is one of Ormat Technologies’ many global geothermal projects.
From 1997-2001, PGV replaced the burning of about 475,000 barrels of fuel oil a year. In that time period, the cost of one barrel was around $27.37, meaning PGV saved Hawaiian Electric about $13 million a year on fuel costs. The PVG plant reduces the amount of fuel oil that needs to be shipped from the refineries on O’ahu, which also then reduces the risk of oil spills.
The Puna Geothermal Venture originally generated electricity from 1993-2018, and comprised 31% of the electricity demand on the Island of Hawai’i (more than half of the island’s renewable energy production). However, in May of 2018, the Kilauea volcano erupted and the production field was partly buried beneath a lava flow causing the PVG power plant to shut down.
After two and a half years of work between Ormat Technologies and Hawaiian Electric, PVG resumed operations on November 5, 2020. Currently, the plant generates 24 megawatts of the original 38 MW. However, it still supplies around 20% of the power needs of the island.
The reappearance of geothermal energy on the island puts Hawai’i back on track to meet the goals established in the 2008 Hawai’i Clean Energy Initiative (HCEI). The HCEI is a partnership between the state of Hawai’i and the Federal U.S. Department of Energy and is an attempt to reduce Hawai’i’s use of petroleum and other fossil fuels for its energy needs. The initial goal was to have a 70% clean energy economy by 2030. Hawai’i’s renewable portfolio standard was amended to make Hawai’i the first state to have a legally required deadline of having 100% of its electricity come from renewable sources.
While geothermal energy currently only provides 5% of Hawai’i’s renewable electricity supplies, the reopening of PGV allows for even further development of the resource. The Hawai’i State Energy Office found in 2016 that the Island of Hawai’i may have more than 1,000 megawatts of geothermal reserves – enough to power Maui, the Big Island, and a quarter of O’ahu collectively.
Did you know... one of the world’s largest hot springs is in New Zealand?
Located in the Waimangu Volcanic Rift Valley near Rotorua, Frying Pan Lake is one of the world’s largest hot springs! It is also one of the youngest, with a precise birthdate of April 3, 1917, having filled and formed in the aftermath of a hydrothermal eruption that lasted three days.
The origin of the lake dates to the early morning hours of June 10, 1886, when Mount Tarawera came to life. This is New Zealand’s deadliest volcanic eruption, even if it was small in size and lasted just a few hours. A line of craters 16 km (~10 mi) long was the result. One, Echo Crater, which hosts Frying Pan Lake, was transformed in the years that followed into a flat-bottomed basin by the erosion-sedimentation of loose ash that blanketed the surrounding hillsides. Because of the steam vents that dotted the basin floor, it became known as Frying Pan Flat.
The hot lake covers an area of 38,000 m2 (~409,030 ft2) and reaches 15 m (45 ft) depth. Swirls of steam rise off the lake surface owing to the inflow of boiling water from four underwater vents. Hot water (50-60˚C; 122-140˚F) overflows the east side of the lake at up to 2000 gallons/minute.
Frying Pan Lake hosts a variety of thermophile organisms, including cyanobacteria and the single-celled archaea. These represent some of the earliest forms of life, making it a modern laboratory for field study of evolution in extreme conditions.
Waimangu is open to tourists. A self-guided nature walk takes one around the edge of Frying Pan Lake. Other amazing sights include the aqua-colored and hot Inferno crater lake, spouting hot springs, silica stalagtites, and Lake Rotomahana, which was the site of the famous Pink and White silica terraces.
Did you know... there’s a financial institution that’s banking on geothermal energy?
Located in Las Tablas, Madrid, Spain, the headquarters of Banco Bilbao Vizcaya Argentaria, S.A.(BBVA), La Vela “The Sail”, is 93 m (~305 ft) high and has 19 floors. It resides in a 114,000 m2 (~1,227,086 ft2) office and service building complex, which includes seven more three-floor buildings. It is also heated and cooled using geothermal energy.
The headquarters were built with the sustainability criteria necessary to be deemed LEED gold certified, which is the strictest sustainable construction standard. La Vela and the other buildings were built using low environmental impact materials and have remote energy consumption monitoring technologies.
There are multiple renewable energy systems being used throughout the complex. Along with solar and water collection/recycling systems, the buildings have also installed closed-loop geothermal systems. The installation of these systems curbs the complex’s energy consumption by 8.3% and carbon emissions by 7.6%.
Did you know... there is a place where the bath water never gets cold?
Something you might not know about Bath, England is that it was named for the thermal hot springs used as Roman baths. The natural springs were first discovered by Prince Bladud and his pigs around 863 BC. It is said he was cured from a skin disease (leprosy) after bathing in the healing waters. Subsequently, the baths were used by the Celts, Saxons, Georgians, and, of course, the Romans.
In the 17th and 18th century fashionable society found it very popular to bathe in the hot springs because of the perceived health benefits.
In the heart of the city, there are three natural springs. The biggest and most notable one is the King’s Spring, which is located in the Roman Baths Museum. The other, smaller springs, Hetling Spring and Cross Bath Spring are about 150 m west of the King’s Spring.
The thermal waters contain dissolved salts from over 40 different minerals, leading to elevated concentrations of calcium, sulphate, and chloride. The deep mineral-rich water has a constant temperature of at least 45˚C (113˚F) and the flow is approximately one million liters per day, supplying the four baths at the Thermae Bath Spa.
The bath water comes from rainfall that percolates through the soil into the underground limestone aquifers between 2,700 and 4,300 meters (8,900 and 14,100 feet) deep. Once heated, the water becomes buoyant and it flows upwards through fissures and faults to reach the surface and the baths. The hydrothermal system that provides hot water to the baths resembles an Enhanced Geothermal System (EGS), wherein hot rocks transfer energy to cold water to create geothermal power.
Did you know… three of the largest geothermal power plants in the world are found in Indonesia?
Indonesia is home to beautiful tropical islands, a rich and vibrant culture, and geothermal power plants! The first exploration geothermal wells were drilled in the 1920s, but the first power production did not start until 1978 at Kamojang. Today, there are over 17 producing fields, including three of the world’s largest.
The biggest is called Gunung Salak, which is located 70 km from Jakarta, the Indonesian capital, on the island of Java with an installed capacity of 377 MW. The field was drilled and put into production by Unocal in 1994 and later acquired by Chevron in 2005. In December of 2016, the field was taken over by Star Energy. Electricity is generated and sold by the state-owned company, PLN.
The second biggest field is Sarulla. It generates 330 MW of electricity and is based in the Tapanuli Utara district of the North Sumatra Province. The project is owned by the Sarulla Operations Limited consortium and electricity is generated by three units of 110 MW each. The first unit was commissioned in March of 2017 and the second in October of the same year. The third unit was commissioned in May of 2018. Geothermal power supplies electricity to approximately 2.1 million homes.
The third largest geothermal project is Darajat which is located 270 km southeast of Jakarata near Garut in the Parirwangi District of West Java. The installed capacity is 271 MW and the resource was initially developed by Amoseas, later acquired by Chevron and since 2016 it has been run by Star Energy. The first power generation commenced in 1994, with the commissioning of a 55 MW unit. A 95 MW unit was commissioned in 2000 and a third unit capable of generating 121 MW was commissioned in 2007.
It is no wonder Indonesia is the second largest producer of geothermal energy in the world, with huge potential for additional growth.
Did you know… Italy is home to the oldest geothermal plant in the world?
The first geothermal plant in the world is located in Tuscany, Italy.
The Larderello geothermal plant was constructed in the early twentieth century thanks to Prince Piero Ginori Conti of Trevignano. Through his work in the processing of boric acid, Conti found his way into the world of geothermal energy and, in 1904, created the first geothermal energy generator.
Stationed in the Larderello dry steam field, his generator could produce up to 10 kW of energy. It also powered five light bulbs.
From there, Larderello’s geothermal potential expanded. In 1911, in an area called Devil’s Valley, construction of a geothermal plant was begun. The plant was completed in 1913.
That first plant, Larderello 1, had a capacity of 250 kW and could produce 2750 kW of electricity. That electricity powered the Italian railway system as well as the nearby villages of Volterra and Larderello.
The original plant has been gradually expanded over the years and now consists of 34 plants, which are operated by the Italian company Enel Green Power, or EGP. The site has a capacity of 800MW, which has resulted in Italy becoming the sixth-largest geothermal energy producer in the world.
Did you know... Mount Erebus is the southernmost volcano in the world?
Located on the western half of Ross Island stands Mount Erebus – the tallest active volcano in Antarctica. Mt Erebus is the largest and only active center of the four volcanic peaks (Mt. Bird, Mt. Terra Nova, and Mt. Terror) that make up the triangular-shaped island.
Erebus is the southernmost volcano in the world, and it is most famous for its lava lake and ice fumaroles. Sitting on a relatively thin continental crust, molten magma easily erupts on the surface, having originated from deep in the Earth’s interior. Continuous emissions of gas and steam provide just the right conditions for building towering columns of ice known as ice fumaroles. Volcanic eruptions are frequent, but the blasts are relatively mild and of the Strombolian-type.
The stratovolcano is 3794 meters (12,447 feet) above sea level. The average summit temperature is around -20˚C (-4˚F) during the summer and -50˚C (-58˚F) in the winter.
Erebus glacier extends down the lower flanks of the cone. Where it flows into McMurdo Sound at sea level, an impressive 11-kilometer (~ 7 mile) long ice tongue protrudes into the sea as the annual snowfall exceeds the annual snowmelt. The ice tongue ranges 50 to 300 m (~164 to 984 ft) in thickness and stands 10 meters (33 feet) above the waterline.
Mount Erebus was first discovered and seen erupting by Captain James Ross, an explorer, in 1841 when he and his crew sailed past the island. It was later scaled by members of an expedition led by Ernest Shackleton in 1908. However, in the following 100 years, it has been rarely visited.
All photo credits to Phil Wannamaker.
Did you know… there is a submarine volcano in Antarctica?
Deception Island, Antarctica is home to an active submarine volcano which has created a large volcanic crater in the middle of the South Shetland Islands.
The total land area of the island is 98.5 km2(~38.0 mi2), with a diameter of 15 km (~9.3 mi). The island rises up to 539 m (~1768.4 ft) above the sea level. More than 57% of the island is covered by permanent glaciers.
The average annual air temperature is -3˚C (26.6˚F); however, temperatures can range from a high of 11˚C to a chilly -28˚C (51.8˚F to -18.4˚F.)
The island’s geothermal heat is found just below the surface. This means visitors can dig a shallow depression into black sand beaches to enjoy the warmth - especially appealing after taking a
Technically, there are no official hot springs on the island, however, along the shoreline of Pendulum Cove, there are thermal springs with temperatures over 70˚C (158˚F). Due to the mixture the cold and hot water, a natural hot tub is created.
But before you jump in, consult a trained expert or experienced expedition guide. They know which areas are safe for a relaxing soak in the steamy water.
Stay tuned to learn about the other active volcano, Erebus.
Did you know… Alaska uses geothermal energy to produce electricity?
It might seem highly unlikely that geothermal energy could be harnessed in the Arctic climate of Alaska considering HOT water is required. However, this is not the case! Geothermal reservoirs can be found almost anywhere in the world. In fact, Alaska has 97 known thermal springs and is one of eight states to use geothermal energy to produce electricity. The first geothermal power plant in Alaska launched in 2006 at Chena Hot Springs and can generate up to 730 kilowatts of power. It is located in the Interior hot springs geothermal region.
The Chena Hot Springs Resort uses geothermal energy in many different ways. The geothermal energy generated supplies power and heat to its greenhouses, swimming pools, and other facilities. In order to produce the power, a binary plant, that runs on the organic Rankine cycle, is used with a generating capacity of 680 kW. The plant runs on 165˚F (~73.9˚C) water meaning the geothermal power plant generates electricity at the lowest temperature in the world. The resort also has a 16-ton absorption chiller, which uses geothermal energy to keep their outdoor ice museum frozen all year round.
Including the Interior hot springs, there are two other active geothermal regions in Alaska – the Southeast hot springs and the “Ring of Fire” volcanoes. The Interior hot springs run from the Yukon Territory in Canada to the Seward Peninsula in Alaska. The “Ring of Fire” volcanoes include the Alaska Peninsula, Mount Edgecumbe, the Aleutians, and the Wrangell Mountains.
Currently, the Alaska Center for Energy and Power, or ACEP, is working with landowners, multiple utilities, and communities to assess resources and evaluate options for the development of geothermal energy in multiple parts of the state.
Did you know... there is a geyser on one of Saturn's moons?
And not just one, but over 100 huge water-vapor geysers occur at the south pole of Saturn’s moon Enceladus. They are believed to come from an ocean beneath the moon’s outer ice crust in which water comes to the surface through cracks in the ice that are called tiger stripes. Due to Enceladus’ tenuous atmosphere, the water vapor re-freezes and forms ice particles that fall back down to the moon’s surface, covering it in fresh ice that makes Enceladus the brightest object amongst all the planets.
More tantalizing is the scale of geysering. The plumes are the tallest known anywhere in the solar system, rising tens of kilometers above the surface of the moon. They are now known to be the source of Saturn’s E-ring, and the eruptions might be triggered by tidal forces. Remarkably, Enceladus is only about 500 km in diameter. The photographs from the Cassini mission from 2006 to 2017 have provided amazing insights about extraordinary geological activity on this small icy moon.
Geyser plumes on Enceladus (Courtesy NASA/JPL-Caltech). https://solarsystem.nasa.gov/resources/806/bursting-at-the-seams-the-geyser-basin-of-enceladus/
Enceladus geysers feed Saturn’s E-ring (Courtesy NASA/JPL-Caltech). https://www.jpl.nasa.gov/images/ghostly-fingers-of-enceladus