As pressure mounts to decarbonize the power sector amid the threat of climate change, the government has proposed greatly expanding renewables’ share of electricity generation to up to 50% by 2040.
Critics have argued that’s not nearly enough for the world’s No. 5 carbon dioxide emitter, but major investments in renewables will still be required even if the target is relatively modest.
While the largest sources are expected to be solar (22-29% of total electricity supply), hydro (8-10%) and from on and offshore wind (4-8%), the plan also calls for raising geothermal energy to 1%-2% of total power, a reflection of Prime Minister Shigeru Ishiba’s stated desire to see Japan develop a renewable energy source it has in abundance.
Rules regarding drilling for geothermal in national parks, where much of it is located, have presented significant legal and administrative barriers over the years to taking full advantage of this resource, although recent changes have opened the door to further development.
Political obstacles remain, starting with individual owners in an industry who worry about the impact geothermal will have on an experience that is almost synonymous with rural tourism in Japan: Hot spring resorts.
Big potential
Past political debate on renewable energy has usually centered on increasing just two sources: solar and wind, especially offshore wind power.
Ishiba’s interest in geothermal is not without merit: Japan sits on some of the world’s most abundant geothermal resources. It boasts the world’s third-largest potential supply of the energy resource, behind only the United States and Indonesia, according to the Japan Organization for Metals and Energy Security (JOGMEC), which is in charge of developing geothermal. The country’s estimated reserves are equivalent to roughly 23 nuclear reactors.
The idea of geothermal for electricity generation in Japan is not new: The first geothermal power plant began operation in 1919 in the hot springs resort town of Beppu, Oita Prefecture.
But despite its long history and potential, geothermal provided just 0.3% of the overall energy mix in the fiscal year from April 2023, the industry ministry said in a report this month. That compares to 9.8% for solar, 7.6% for hydropower and 1.1% for on and offshore wind. Japan was ranked 10th for geothermal power generation capacity in 2023 by ThinkGeoEnergy, a newsletter for the industry. The U.S. held the top spot, with 3,900 MW (3.9 GW).
In a report published earlier this month on geothermal energy’s future, the International Energy Agency said that with technology improvements and project cost reductions, geothermal, currently supplying 1% of global energy demand, could see that share rise to 15% by 2050.
A separate IEA report published earlier this year also puts in plain view how the renewable source has struggled to catch on in Japan.
The IEA notes that Japan’s total geothermal power plant capacity as of March 2023 was about 500 megawatts (MW) — roughly half the power of one conventional nuclear power plant. That figure is virtually unchanged since 1995, when capacity reached 500 MW for the first time — in fact, capacity actually decreased between 2017 and 2023, unlike every other country the IEA surveyed.
The current long-term energy plan for 2030 had called for raising that total to 1.5 GW — about the size of one large nuclear power plant and a miniscule 1% of total electricity supply.
But Ishiba sees geothermal energy as a key component of Japan’s push to decarbonize and meet its 2050 carbon neutrality goal, as well as a way to spur regional revitalization, which may have prompted the government to raise the target for 2040 to up to 2%.
“Expanding the number of regions that are leading the way in decarbonization through the use of local forest resources and developing geothermal and small- and medium-scale hydropower will bring benefits to local economies,” Ishiba told a meeting of the government’s green transformation (GX) committee on Oct. 31.
Political backing
Ishiba appears to have a solid base of political support for his effort. Prior to the Oct. 27 election for the 435-seat Lower House, nearly 100 parliamentary members belonged to a group pushing for the use of more geothermal energy, with over half from the ruling Liberal Democratic Party and Komeito.
The rest were mostly from the major opposition parties, including Constitutional Democratic Party of Japan, the Democratic Party for the People and Nippon Ishin no Kai.
While solar is unlikely to be unseated in the near term as Japan’s top source of renewable energy, lawmakers see big potential for geothermal energy.
| Getty Images
One of the core members of the group is the LDP’s Goshi Hosono, a former environment minister.
“The parliamentary group supporting geothermal is quite broad in terms of its membership and has a lot of political power. Former LDP Secretary-General Toshihiro Nikai (the titular head of the association), did not seek re-election on Oct. 27 and retired from politics, however, so the group has to make a new start,” Hosono said.
“But Ishiba has long been a strong supporter of geothermal energy, because it can lead to regional revitalization,” he added, especially since geothermal resources are often located in rural areas of the country.
Hurdles remain
While the potential for Japan to greatly expand geothermal power is widely recognized, there have traditionally been several barriers standing in the way of tapping this clean energy source.
Many of the ideal locations for setting up geothermal plants are located in national or quasi-national park areas — an estimated 80% of the country’s geothermal energy potential falls within these jurisdictions.
For decades, strict environmental regulations on drilling inside parks made developing their geothermal resources all but impossible. However, Hosono said that after the March 2011 earthquake and tsunami, which caused a massive meltdown at the Fukushima No. 1 nuclear power plant, calls have grown to make better use of renewable energy, including geothermal.
The result was that, in 2015, the government issued new directives that relaxed restrictions on drilling in national parks, a significant step toward removing that obstacle.
Instead, the more intractable problem has been from local onsen (hot spring) owners, who fear that damage to water quality due to geothermal drilling in their neighborhood would drive away customers.
The Japan Onsen Association, which has about 1,300 members nationwide, was established in 1929 and is the largest lobby group for the industry. In 2021, it petitioned the Environment Ministry, saying it opposed geothermal power development.
“There have been reports from hot springs resorts of problems such as the drying up of hot spring water sources, changes in water quality and a decrease in water due to geothermal development. We believe geothermal development through large-scale, deep drilling will definitely have an impact on hot spring sources,” the petition said.
The Japan Onsen Association has expressed concerns about the impact of geothermal energy on the hot spring resorts run by its members.
| Getty Images
The association, however, says it is not opposed to geothermal development in and of itself. Small-scale geothermal power plants could revitalize local communities, it said. Rather, their worry is about binary generation.
Binary-cycle geothermal power plants use lower temperature geothermal resources than other types of power generation. These geothermal fluids pass through a heat exchanger along with a secondary, or “binary,” fluid that has a lower boiling point than water, according to the U.S. Department of Energy’s website. The result from the modest geothermal resource heat is a vapor that drives the turbines, spins the generators and creates electricity.
“Unlike the standards for deep drilling and large-scale geothermal power generation, the regulatory standards for binary generation are loose. Heat sources in shallower layers of the Earth are often used, and this is why there have been some problems with hot spring owners,” the group said.
The association listed five things it wanted from the government in order to get on board with geothermal development:
- Consensus of local communities, including local governments and hot springs operators.
- Creation of a third party to monitor the mutual disclosure of information about geothermal development.
- Regulations to prevent the overcollection of steam for geothermal plant use.
- Extensive, continuous environmental monitoring of geothermal plants.
- Clarifying who is responsible for restoration work in hot spring areas that have been damaged by geothermal development.
“We hope that, as the Ishiba administration makes its plans for geothermal development, the above five proposals will be followed,” the association said in a written statement to The Japan Times.
Some local municipalities, however, are taking it upon themselves to discourage more geothermal development.
Beppu, Oita Prefecture, a popular destination for holidaymakers due to its hot spring resorts, passed an ordinance in 2022 that forbids drilling in certain areas, claiming that geothermal generation was lowering water temperatures.
| Getty Images
Beppu, a popular destination for holidaymakers due to its hot spring resorts, passed an ordinance in 2022 that forbids drilling in certain areas, claiming that geothermal generation was lowering water temperatures.
Naoki Masuhara, an associate professor at the University of Hyogo’s School of Human Science and Environment who has written about disputes over geothermal power, says that while it’s said there are no reported cases in Japan of hot springs drying up due to geothermal power generation, that hasn’t lessened the opposition.
“It’s difficult to gain the understanding of people involved with hot springs resorts, because the hot springs water, and geothermal activity, are underground and not visible,” he says.
Geothermal’s future
Utilities, for their part, are more diverse in their views on geothermal. Those that generally service more rural areas with lots of geothermal reserves are more keen on development than utilities that service customers in the country’s largest urban centers.
“Kyushu Electric, Tohoku Electric and Hokkaido Electric are supportive of geothermal. Even Chubu Electric is becoming more keen on it,” Hosono says.
On the other hand, he adds, utilities like Tokyo Electric and Kansai Electric, partially due to their huge investments in other energy forms such as nuclear power, are less passionate about developing geothermal resources.
In the meantime, the government is backing a plan that will allow JOGMEC to conduct surveys of sites where geothermal drilling and development might be possible. The Ministry of Economy, Trade, and Industry will choose candidate sites for the surveys in fiscal 2025 and carry them out in fiscal 2026.
An IEA report published earlier this year notes that JOGMEC has been developing cost-effective and highly accurate geothermal exploration technologies to improve how geothermal sources are identified.
Some geothermal sites have also seen their capacity reduced over the years because of a shortage of water in the reservoir, the report said. To fix that problem, the METI-affiliated organization has started to develop technology for “more appropriate water recharge into geothermal reservoirs,” which could help optimize and stabilize stream production.
Japanese scientists are also researching “thermal-shock drilling,” in which rocks are rapidly heated and cooled in order to create cracks and make drilling into them easier and more efficient. The technology is in its infancy, however.
“Next-generation geothermal could also play a significant role in Japan, which has high-quality resources and significant opportunities to cut fossil fuel imports and enhance its energy independence,” the IEA noted in its December report.
But ultimately convincing local communities that the initial surveys — and, if chosen for development, the drilling and use of geothermal resources — will not negatively impact either the business at surrounding hot springs locations or create environmental damage will be up to the government.
That may require more than just dry assurances from engineering experts about improved technological developments. Nobody doubts that Japan has the potential to become a geothermal superpower.
The question is whether it has the political will to do so.
