Magma and hot rocks: Iceland seeks the future of geothermal energy

REYKJAVÍK, Iceland — The signs of Iceland’s geothermal riches are hard to miss. Earlier this summer, bright orange lava sprayed like a fountain and flowed like a river from an active volcano, visible from miles away. Out on older lava fields, thick steam clouds rose from the ground as the earth brimmed with heat. The famous Blue Lagoon offered yet another reminder: The spa’s milky-teal water comes from the runoff of an adjacent geothermal power plant.

For decades, Iceland has harnessed this natural abundance to heat the majority of its homes and produce a sizable share of the country’s electricity supply. Outdoor swimming pools, streets, and sidewalks stay free of ice and snow during the long Nordic winters thanks to the geothermal resources piped beneath them.

The country is an undisputed leader in geothermal energy, which is drawing increasing attention globally as an on-demand source of renewable energy. Yet Iceland hasn’t fully unlocked its potential. Hidden from sight, miles beneath the surface, scalding-hot rocks and churning magma chambers are the latest frontiers in geothermal energy, promising a clean and inexhaustible supply of heat and electricity — if only scientists and engineers can figure out how to extract it.

New research projects are underway to drill into those resources in Iceland, and experts from the United States and other countries are collaborating and watching closely. By gathering data and developing technology in the most extreme environments, Iceland aims to export its findings to unleash geothermal energy in places without flowing lava and seething hot springs.

“A big goal of ours is to use Iceland as a test bed,” said Hjalti Páll Ingólfsson, director of the Geothermal Research Cluster, or GEORG. He spoke in late May on the sidelines of the Iceland Geothermal Conference, held inside the glimmering Harpa concert hall in downtown Reykjavík.

The conference took place during a momentous period for the global geothermal industry. In the U.S. and worldwide, private companies and government agencies are ramping up support for geothermal projects while working to meet the world’s urgent need for renewable, carbon-free energy — and for around-the-clock power that can fill in the gaps left by intermittent sources like wind and solar.

At last year’s United Nations climate change conference in Dubai, countries committed to tripling the world’s installed renewable energy capacity by 2030 to align with international climate targets. For geothermal in particular, meeting that pledge will require adding 48 gigawatts of electricity capacity and 520 gigawatts of thermal heating and cooling capacity, all in about six years’ time.

“If you do the back-of-the-envelope calculations, it means we have to start drilling 20,000 wells per year … to get that energy we’ve pledged towards by the end of this decade,” Marit Brommer, executive director of the International Geothermal Association, said during the conference. Today, the industry drills around 1,500 geothermal wells every year.

Such dramatic goals underscore the need to tap into deeper, hotter resources. Companies produce geothermal power by extracting hot water or steam from underground wells and using the heat to drive turbines. The hotter the fluid, the more efficient and powerful the system, meaning companies can derive more energy from a smaller number of wells.

This is why Iceland is exploring the potential of drilling near volcanoes and into superhot rock formations. These attempts are still in their infancy and will likely require significant research funding and repeated trial and error before the concepts can be transformed into commercial-scale projects. But proponents say the efforts are worth it. Even Iceland’s conventional, easy-to-reach geothermal resources likely won’t be sufficient to serve the rising urban population, the shift to electric vehicles, and industrial growth.

“We need to think about how we’re going to provide both electricity and district heating for people 100 years from now,” said Arna Pálsdóttir, head of resource innovation at Reykjavík Energy, the utility company serving the capital region. ​“We’re really figuring out everything we can at this point so that we’re ready for the future.”

Drilling deep and striking magma 

Iceland has been working to crack the code on supercharged geothermal for over two decades.

In 2000, the National Energy Authority and leading energy companies formed the Iceland Deep Drilling Project (IDDP) to improve the economic case for geothermal production by tapping into reservoirs of ​“supercritical” fluid — a steam-like phase that carries three to four times more energy than regular hot water.

Nine years later, the IDDP team began drilling the first well, near the Krafla volcanic caldera in northeastern Iceland. The goal was to reach down nearly 3 miles below the surface. But at around the halfway point, the drill got stuck. When engineers pulled it back out, the equipment was covered in crystallizing volcanic glass. The team had unwittingly struck magma.

They seized the opportunity and began running tests in the borehole, which gave researchers their first inkling about the staggering energy potential near volcanic sites. A typical high-temperature well in Iceland might deliver around 5 megawatts of energy output. IDDP estimated that harnessing the supercritical fluid near magma could deliver around 50 MW — one superwell to replace 10 regular ones.

“There’s a possibility to get so much more out of the sites than we are today,” said Björn Þór Guðmundsson, CEO of the Krafla Magma Testbed (KMT), a nonprofit research initiative that was established in 2014. ​“At the moment, we’re basically just eating the crumbs on the plate but not eating the cake itself.”

In 2017, IDDP drilled a second well, on the Reykjanes peninsula, and successfully reached its target depth of over 2.8 miles. But, just as with the first well, the drilling project revealed significant challenges. At extreme temperatures and pressures, the fluids and gases in the ground corrode or dissolve drilling equipment and well casings — the steel pipes that help bring steam and water to the surface. Neither project team could keep the wells from collapsing, let alone capture the heat simmering far below.

To address these problems, KMT is preparing to drill two new research wells into magma chambers near Krafla, where it is launching what it calls the world’s first magma observatory. This year, the organization plans to start raising $105 million from companies and research institutes to fund the project through 2030, the results of which could be shared publicly or among researchers.

The first well, which KMT aims to drill in 2026, will mainly be geared toward studying and measuring magma itself. Scientists will place sensors directly into the magma and use the data to develop methods for detecting pools of liquid rock in other places. The goal is to find the hot pockets without the drills getting stuck in treacly magma; another focus is to get better at predicting volcanic activity.

“It’s not enough to be able to drill close to them and extract the energy,” Guðmundsson said during a conversation outside the geothermal conference. ​“We have to know where [the chambers] are in order to do so.”

In 2028, KMT plans to drill the second well close to where researchers accidentally struck magma in 2009 and will attempt to extract heat and potentially produce power. This time, however, scientists will use materials that they hope can withstand the highly corrosive environment — not just in Iceland, but in volcanic regions around the world. 

Some 1 billion people globally live within roughly 60 miles of a volcano, representing a huge swath of the world’s potential energy users. ​“If we can create wells that can withstand conditions in Krafla, it will be very hard to find conditions that they won’t be able to withstand, because these are very extreme,” Guðmundsson said.

Harnessing hot, dry rocks 

Another initiative in Iceland could unleash geothermal resources for the billions of us who don’t live near volcanoes.

Reykjavík Energy is planning to drill down into superhot conditions of around 750 degrees Fahrenheit. But unlike with most existing geothermal projects, the company won’t be looking to flow up hot water or supercritical fluids found naturally underground. Instead, the goal is to drill into dry rocks, then fracture the rocks and pump down water to create artificial reservoirs — an approach that could potentially be replicated in many other parts of the world.

That effort will be the third and latest drilling project under the IDDP umbrella. In late May, Reykjavík Energy shared its plans at a workshop inside Harpa, overlooking the placid Faxaflói Bay. The utility said it will collaborate with Clean Air Task Force, a U.S. advocacy group, and Transition Labs, an Icelandic nongovernmental organization, to share learnings from the $15 million to $20 million research project. Drilling is slated to begin around 2027 or 2028, at a site near the Nesjavellir geothermal power plant.

Fracturing rocks to produce geothermal energy is an emerging but proven concept. In the U.S., the startup Fervo Energy is using horizontal drilling techniques pioneered by the oil and gas industry to build the nation’s first commercial ​“enhanced geothermal systems” in Nevada and Utah. But Fervo isn’t drilling into superhot rock conditions, at least not yet.

“There are a lot of knowledge gaps, because no one’s done this before,” said Trenton Cladouhos, vice president of geothermal resource development for Quaise Energy. The Cambridge, Massachusetts–based startup is developing high-frequency beams that melt and vaporize rocks, in hopes of drilling into ultradeep, superhot formations.

At the workshop, Cladouhos presented new computer modeling that suggests a superhot system can deliver five to 10 times more power than is produced today from enhanced geothermal systems for up to two decades. It also indicated that superhot rocks will behave differently, possibly creating a large ​“cloud” of tiny fractures instead of a few large fractures, as at lower-temperature conditions.

“The model doesn’t actually give a recipe to how to create fractures at these [extreme] temperatures,” Cladouhos said later by phone. ​“So that’s really what we want to do in the field, is figure out that recipe.” By early next year, Quaise plans to conduct its first field test by boring a 330-foot-deep hole at a quarry in Texas using its novel drilling technology.

Meanwhile, in Iceland, Reykjavík Energy is planning to begin a smaller research effort later this year, Pálsdóttir, the utility’s head of resource innovation, explained on a call in mid-July.

In previous deep-drilling projects, the ultrahigh temperatures caused well casings to expand and crack from the thermal stress. The company plans to test new flexible ​“couplings” connecting pipe segments in a typical geothermal well in the coming months to see if they could provide a fix. Researchers are also working to develop more corrosion-resistant equipment that can handle the acidic, mineral-rich fluids that flow through these systems.

Pálsdóttir said she doesn’t expect that drilling into the ground itself will induce earthquakes. But the process of reinjecting water and fluid into the ground after energy is extracted can sometimes induce seismicity, which happened near one of Reykjavík Energy’s geothermal power plants around 2006. The company has since developed protocols for limiting and avoiding earthquakes, and for distinguishing human-caused seismicity from Iceland’s natural rumblings, she said

A U.S.-based startup is pursuing a similar drilling project in Oregon. Mazama Energy plans to demonstrate a superhot enhanced geothermal system on the western flank of the Newberry Volcano, which has been described as ​“the biggest untapped geothermal resource in North America.” Earlier this year, the U.S. Department of Energy selected Mazama’s pilot project and two others to receive up to $60 million from the Geothermal Technologies Office.

As the projects get underway in Iceland and Oregon, Clean Air Task Force will be working to help companies share data and findings so that the broader industry ​“can learn from each other and do it better, faster, cheaper,” said Terra Rogers, who leads the organization’s superhot rock energy program.

“Every effort to demonstrate how ubiquitous and abundant this resource is is a step in the right direction,” she said, noting that geothermal ​“could really have an impact and timeline that’s meaningful for the climate.”

Rogers and other superhot proponents claim these projects aren’t moonshots. KMT’s Guðmundsson, speaking at the concert hall in Reykjavík, said these efforts aren’t as scientifically ambitious as, say, space exploration or nuclear fusion, two highly uncertain fields that have no shortage of public and private funding.

“Why are we not putting the same amount of money into researching the earth and trying to harness this extreme energy?” he said. ​“We have abundant green energy beneath our feet. We just have to create methods to reach that energy.”

Note: Canary Media traveled to Iceland as part of a paid press trip organized by Green by Iceland, a public-private partnership supporting Iceland’s business sector.