How Japan is looking deep underground to solve its carbon problem

According to the government’s CCS roadmap, Japan aims to annually store an estimated 120 million to 240 million tons of CO2 by 2050, the high end of which would require establishing roughly 480 injection wells, at an estimated cost of ¥5 billion or ¥8 billion per well depending on whether it is on or offshore.

The five JOGMEC-supported projects that plan to store CO2 off Japan’s coasts are near Hokkaido, western Tohoku, Niigata Prefecture, western Kyushu and Chiba. Most intend to inject the CO2 into saline aquifers — a type of underground rock formation thought to have the largest capacity and greatest safety for CO2 storage — while the Niigata site targets an oil and gas field.

The Hokkaido-based project is actually a continuation of an existing CCS initiative, supported by the government’s New Energy and Industrial Technology Development Organization, in the port city of Tomakomai. From 2016 to 2019, the pilot facility — which cost approximately ¥30 billion to construct — captured roughly 300,000 tons of CO2 and injected it about 1,000 meters below the nearby seabed. Operators have been monitoring the site for seepage, an issue that has impacted CCS projects overseas, and seismic activity since then. So far, so good, they say.

Naturally, thorough monitoring doesn’t come cheap. At Tomakomai, operators installed expensive equipment on the ocean floor to receive real-time data, explains Hiroshi Nambo, the Global CCS Institute’s Japan branch representative.

“Monitoring is important, but … the cost of monitoring should be minimized,” he says.

A JOGMEC spokesperson echoes that sentiment, noting that the method, frequency and duration of monitoring across the nine exploratory projects will depend on both regulatory requirements and cost-effectiveness. Monitoring plans — still under consideration — may therefore differ by project and by site, the spokesperson explains.

Although Japan’s new CCS Business Act does require monitoring, including after CO2 injection finishes, it does not specify minimum monitoring requirements.

Alongside further assessment of potential storage sites, clarifying CCS’s costs is a major goal of the exploratory projects.

“The capture technology is ready and emission sources are ready,” Nambo says. “The problem is economics: how the project proponents prepare that investment and how to justify the economics for the total operation period.”

In a 2024 report, the Oil and Gas Climate Initiative, an industry-led organization, assessed that Japan has 152.27 gigatons of CO2 storage capacity, but so far none of that has been judged economical to access.

“Government financial support is absolutely necessary” at this stage, Nambo says.

In a December government estimate of electricity costs in 2040, power generated at CCS-equipped gas and coal power plants was more expensive compared with all renewables (aside from small-scale hydropower and controversial biomass). If deployed, CCS’s high costs will likely be shouldered by residents, whether through increased electricity bills or higher public spending, critics say.

Keep it in the ground

Carbon capture technologies target CO2 generated at various points in the combustion process or capture it directly from the air. The JOGMEC-supported projects all plan to use the former, a comparatively easier approach, capturing carbon from specific facilities.

Still, the rate of carbon actually captured by that CCS technology is another point of contention between proponents and critics.

Roughly 95% — or even close to 100% — of CO2 passed through a capture plant can be secured, says Alex Zapantis, a strategic adviser with the Global CCS Institute.

“Not all of the CO2 from a facility is passing through the capture plant in most places,” Zapantis explains. “Ultimately, it’s an economic decision” as to how much CO2 an operator will aim to capture, he says, noting that market demand is now dictating capture rates as close to 100% as possible.

However, IEEFA analysts highlight that, based on available data, CCS projects to date have only captured a maximum of roughly 80% of the CO2 passed through the capture technology. In many cases, that percentage is much lower.

“Unfortunately, most of the existing carbon capture facilities do not publish … their actual CO2 capture rates,” a 2023 IEEFA report noted.

For the nine CCS projects selected by JOGMEC, “no target is set for the recovery rate for the total CO2 emissions of the facilities subject to CO2 capture. Targets are being considered based on what is reasonable for each facility, including their technical and business aspects,” the JOGMEC spokesperson says.

In addition to achieving meaningful capture rates, using CCS as a climate solution means operators also need to find secure locations to keep all the captured carbon stored for at least hundreds of years.

Grant Hauber, a strategic energy finance adviser with IEEFA, cited the Snohvit CCS project in Norway as an example of what can go wrong, even with careful preparation. Snohvit’s original storage site, projected to have 18 years’ worth of capacity, proved unusable after only 18 months, as CO2 was not being absorbed at the predicted rate, forcing operators to find alternative storage sites.

“You can have the best scientists in the world working on planning, but, in operations, they don’t know how the CO2 will behave until they start putting it in the ground. It’s effectively a gamble,” Hauber says.

He adds that “CO2 in the form it’s injected underground … is highly corrosive,” noting that CO2-induced decay of well casings led to leaks at a seven-year-old CCS site in Illinois, leading to the suspension of operations in 2024.

Leaks can be dangerous. In 2020, 45 people in a Mississippi community were hospitalized when a CO2 pipeline ruptured; CO2 displaced the oxygen in the air and caused people to experience breathing difficulties — some fell unconscious.

However, Zapantis emphasizes that, overall, CCS has an “excellent safety record” across industry’s “more than half a century of experience transporting very large quantities of CO2 via pipeline.”

Still, given the challenges and costs associated with CCS, there is a strong debate over just how widely it should be deployed.

Zapantis says he sees CCS having a role in decarbonizing Japan’s heavy-emitting industries and fossil fuel-dependent power sector. Meanwhile, Hauber argues CCS should be limited to a small subset of industry where CO2 emissions are an unavoidable byproduct of chemical processes.

Climate advocates also question Japan’s CCS plans.

“CCS should certainly not be used in the power sector, where other options for decarbonization are available,” says FOE’s Fukakusa.

“No matter what sector CCS is used in, the challenges of storing CO2 underground are the same,” she adds. “There still hasn’t been sufficient assessment of which emission sources actually need CCS.”

‘Carbon colonialism’

The four projects aiming to bury CO2 overseas are targeting sites in Malaysia, Indonesia and Australia. Oil and gas giants ExxonMobil and Petronas are among those involved.

The CO2 captured in Japan would need to be transported via a fleet of specialized ships, which are still being developed and tested. Domestic testing using a single vessel began late last year as part of the Tomakomai project.

Although exporting carbon is new territory for Japan, Nambo and Zapantis note that the proposed cross-border projects are straight from the government and industry’s playbook, involving long-term investment in and relationships with overseas partners to ensure multiple sources of a given resource.

“JOGMEC has supported Japanese private companies to secure equity for energy development, including oil, gas, coal and mineral resources overseas,” Nambo says, adding that this is how they are now approaching CO2 storage sites.

Many of the cross-border projects plan to use depleted offshore oil and gas fields as storage sites. Although JOGMEC says that CO2 from the exploratory projects won’t be used for extracting more fossil fuels, IEEFA’s Hauber still cautions that “highly perforated” former extraction sites may not be ideal storage locations.

“There are a lot of potential exit paths to be identified and managed,” he says. “Even if locations of well perforations are known, if inferior materials were used or improperly installed, a leakage situation like that experienced in Illinois could eventually arise.”

If a leak should occur at an overseas storage site, “it will be necessary to take measures in accordance with the CCS-related laws and regulations of the country concerned,” JOGMEC says.

In May 2024, 90 civil society organizations — including 43 from Malaysia, Indonesia, Australia and Japan — sent an open letter to the Japanese government asking it to halt its carbon export plans.

“This is nothing but carbon colonialism,” Fanny Tri Jambore of the nonprofit WALHI Indonesia wrote in a press release accompanying the letter.

While the JOGMEC-supported projects will give the government and industry more data to help determine how to invest in CCS going forward, Fukakusa worries that the technology is being prioritized ahead of proven, cost-competitive solutions.

“The biggest problem is that Japan has no policy to phase out fossil fuels such as coal, natural gas and oil,” she says. “Government and industry emphasize CCS and assume it will be used.”