August 25th 2024

Bathing in hot springs – onsen bathing

• This bathing¹ part of this posting is about the water in the hot springs, not the traditions or manners related to the hot spring bathing culture.
• This posting is designed so that there are a lot of numbers and data to read and practise. There are references for these numbers and data at the bottom of the posting.

There is the constant ² fear that an earthquake could happen any time. This constantly lurking³ worry is caused by the fact that Japan lies on active faults⁴ which are found where plates under the earth meet.

Volcanoes also appear around fault lines and Japan has over 100 active volcanoes, about 10％ of all active volcanoes in the world¹. This means there is magma⁵ underground, close to the surface of the earth.

Japan also has a lot of water, as it rains a lot, so magma together with water equals hot water. This hot water is the source⁶ of the 温泉 onsen. These hot springs have been used for bathing for centuries⁷ and in 2021 people made over a hundred million (100,000,000) trips to hot springs². These trips happened across the 27,000 hot spring sources that are in Japan.

There are many famous hot spring resort areas such as Beppu in Kyūshū or Hakone near Mt. Fuji. Water is considered to be onsen water when it is 25 degrees Celsius when it comes out of the earth or when it has a certain amount of minerals in it³.

The onsen certainly have a lot of charm and different areas have different types of water. Some are by the sea, some are in the mountains and many are in nice locations in the countryside. Different types of water have different minerals in them. The following information gives some examples of the water types and their therapeutic⁸ effects.

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• There are considered to be ten different types of spring water but it is not easy to clearly define each onsen a lot of the time. Below is a little information about six of the types of water.

• 　Simple hot spring water could have little amounts of everything. Good for relaxing in – like all the hot springs.
• Onsen with a good amount of salt are called chloride springs. The salt helps you keep warm after you’ve finished bathing. Sounds good in winter. The salt also kills bacteria, so if you have cuts you’ll thank this water afterwards.

• 　Carbon dioxide CO₂ hot springs have bubbles that stick to your skin. This helps improve your circulation.⁹
• 　Water containing a good amount of iron is brownish and it leaves a brown colour on the stones and wood around it. It’s something different for you to see.

• 　If you have skin problems such as acne you should head to sulphur springs. Like the onsen with iron in them the sulphur onsen colour the stones and wood that the water touches but this time the water is milky white so the stones and wood become whitish, not brown.

• 　If you have painful joints¹⁰ you might benefit from visiting this type of onsen. Hot spring water with radon is good for rheumatism¹¹, so if you want to soothe¹² your muscles, this type of water is particularly good for you.

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Energy Production

Renewable energy sources* – wind, solar, hydropower, geothermal, wave, tidal¹³ and biomass¹⁴.

Geothermal energy** – heat from inside the earth that can be used to create energy. It can be used for bathing, direct heating and generating¹⁵ electricity.

Energy self-sufficiency*** – ¹⁶ If a country is energy self-sufficient it can produce all its energy itself. It doesn’t need to import any energy such as coal, gas and oil. Energy self-sufficiency is also called energy security.

Fossil fuels**** – coal, gas and oil.

Renewable energy* 100％. Geothermal energy**⁴ 60％. Energy self-sufficiency*** 100％. These percentages are for Iceland. Iceland uses geothermal energy both directly for heating and also for making electricity, so the 60% geothermal energy is not just the percentage of electricity produced from geothermal sources.

Thinking about Japan – renewable energy 22.4％ and energy from burning fossil fuels**** in 2021 71.7％⁵ and geothermal energy production around 0.3％⁶ in 2021. The geothermal energy in Japan almost all comes from making electricity.

It should be noted different websites give different figures. According to ourworldindata.org⁷ Japan’s energy production from fossil fuels was around 83％ and energy production from renewable sources was around 13％ in 2023. Energy self-sufficiency was about 11％ around this time according to the Lowry Institute⁸. The self-sufficiency in energy for other eastern Asian countries includes Malaysia at 100％,Thailand at 54％ and the Philippines at 52％, also according to the Lowry Institute in 2023.

The percentage of geothermal energy production is low in Japan. After the Fukushima nuclear accident caused by the tsunami in 2011, energy from renewable sources rose to 16.9％ in 2018 from 10.4％ in 2011 but the geothermal energy percentage showed no change – it was at 0.2％ in 2011 and still 0.2％ in 2018⁹, with it now being only 0.3％, as mentioned above. Why is this the case?

The one major reason seems to be opposition¹⁷ from the onsen industry. Onsen owners don’t want geothermal power plants¹⁸ to be built because they think the power plants will take away the hot spring water sources. This is unlikely to happen though, many geologists¹⁹ have said, as onsen generally use water from shallow sources but geothermal power plants want to get water from much deeper water sources¹⁰.

power plant* – A power plant can also be called a power station.

Restrictions²⁰ and steep mountains are other factors that hinder²¹ geothermal power plant construction and Japan is only using about 1.5％ of accessible geothermal energy sources¹¹. Over 80 ％ of onsen are in national parks and there are strong restrictions on power plant construction.

After the Fukushima nuclear power plant disaster in 2011 restrictions were eased²² a little in 2012 and the number of power plants quadrupled²³ in ten years to over 80 in 2021¹².

However many problems remain and Nobuyuki Ogura who is the chairman of the Japanese Geothermal Association said that one problem is that there is no geothermal law in Japan. There is no legal²⁴ framework to compensate²⁵ onsen owners if their businesses are affected by drilling for geothermal energy sources. Nobuyuki Ogura said New Zealand has such a law and the clear compensation offered to the local²⁶ people helps with negotiations¹³.

A supermarket entrepreneur²⁷ from Hyōgō called Shōji Numata is one of the people trying to change things. He is trying to actively involve local people in the geothermal energy production process. In March 2024 a geothermal power plant started by his company 町おこしエネルギ　Machiokoshi Energy was completed in 小国町 Oguni Machi in Kumamoto, Kyūshū¹⁴ . The locals have their electricity generated for them by the geothermal power plant and the farmers can use the water made available from the geothermal power plant to heat their greenhouses¹⁵.

The type of flash steam geothermal power plant such as the one in Oguni Machi generally takes a long time to be built. A flash steam power plant is one that pumps up the hot water from underground to use the hot water directly to create steam to drive the turbines²⁸. A lot of research is required and this takes time and money.

Thinking about this it seems the policy in Japan has been to look at the short-term benefits and not think of things in the long-term. Fossil fuel power stations are quicker to make a profit²⁹ than geothermal power stations. There are a lot of people with conservative³⁰ ideas who control things and a lot of the onsens are in government strongholds³¹. Could it be that the government doesn’t want to push some of the local communities to accept trying geothermal energy in case the government loses the local people’s votes?

There is hope for the future though if you believe in geothermal energy. The government has said that it wants to increase geothermal energy to 1％ of all energy production by 2030 and the biggest binary cycle geothermal power plant in Japan opened in May this year – that’s May 2024.

Japan is said to have the potential to build a lot of these binary cycle geothermal power plants. These binary power plants use the hot water from underground to heat fluids such as ammonia, which have boiling points lower than water, to make the steam. This steam turns the turbines which make the electricity.

Japan has a lot of lower hot water temperature resources under the ground from between 53 -120 degrees Celsius which are used in these type of binary cycle power plants and binary cycle power plants are not so big and take only about a year to be developed¹⁶. In some cases it does take longer to build these power plants but the fact that Japan has the water resources that suits building small power plants is important when you think that because of all the mountains it is difficult to build huge power plants.

Will the government help make it easier for people with innovative³² ideas such as Shōji Numata to help create projects around Japan or will conservative thinking control things? The project in Oguni Machi was completed around 5 years after research first started. This is quicker than around ten years that it usually takes to build a flash steam power plant and one reason for this was the innovative research equipment. The equipment was transported in bits up the small mountain roads and assembled³³on site¹⁷. Another example of innovative ideas connected to Shōji Numata was the opening of a college in Hokkaido in 2021. The purpose of the college is to educate students about the geothermal world and prepare them for jobs in the geothermal industry. The college is called the Geopower Academy.

Things in Japan can be very innovative in many ways, particularly when thinking about new technologies. Thinking about the turbines used in geothermal power plants, most of them across the world are made by Japanese companies but are not used in Japan. You will probably find many more turbines made by Japanese companies in Kenya than in Japan. Japan has the technology. Will conservative policy makers allow geothermal energy to fully develop?

Geothermal energy production in Kenya is 47％ of total energy production. Japan, as written above, has about 0.3％ of energy produced by geothermal power plants. Kenya only started operating its first geothermal power plant in 1981, 15 years after Japan started operating its first one in Iwate prefecture in 1966¹⁸. However Kenya now creates more than double the amount of geothermal energy of Japan¹⁹, even though Japan has more that double the geothermal energy potential of Kenya²⁰* .

Japan has the third largest potential geothermal energy resources in the world behind the USA and Indonesia. Maybe as Shōji Numata said, Japan needs to speed things up.

土湯温泉 Tsuchiyu Onsen and geothermal power plant is a good example of how bathing and energy production can work together. It started to be developed in 2012 in Fukushima prefecture in 磐梯朝日国立公園 Bandai Asahi National Park and started operation in 2014²¹. It was able to be built after the changes in restrictions regarding building geothermal power plants in national parks that happened after the Fukushima disaster.

The Tsuchiyu Onsen uses both the hot water and cooling water from the power plant. The warm water from the power plant is also used to cultivate shrimp which saves a lot of money. Part of the profits from the geothermal power plant, which is a binary cycle one, pay for the local primary school children’s lunch and helps pay for the local high school student’s and elderly people’s buses²².

When Japan tries to do something innovative and on a small scale, it can do it very well and this Tsuchiyu case shows how everyone can benefit, including the locals – some people can bathe, some can get energy and some can make money and others can save money ……

We often hear about carbon dioxide or CO₂ due to its connection to global warming. Geothermal energy produces almost no CO₂ and is as constant as is the worry about earthquakes. Added to that, it doesn’t come with the fear associated with nuclear plants when an earthquake occurs, a fear that increased dramatically after the Fukushima nuclear disaster. In a country that has frequent earthquakes, with some causing immense destruction, will something positive continue to develop from Japan’s geographical location? In this case the positive thing is geothermal energy and it may one day become almost as much part of the culture as the onsen culture if it is allowed to do so.

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¹ VolcanoDiscovery (2024)

² j-smeca.jp (2023)

³ bathclin.co.jp – Just What Makes a Japanese Onsen (No date given)

⁴ Orkustfnun – Natural Energy Regulatory – Iceland (2023)

⁵ Institute for Sustainable Energy Policies (2022)

⁶ The Japan News (2022)

⁷ International Renewable Energy Agency (2024) – processed by Our World in Data

⁸ Lowry Institute Asia Power Index (2023)

⁹ earthene.com (2022)

¹⁰ EIS Insight (2024)

¹¹ Bloomberg (2023)

¹² Kyodo News (2021)

¹³ Agency for Natuural Resources and Energy (2019)

¹⁴ NHK (2024)

¹⁵ Bloomberg (2023)

¹⁶ Japan for Sustainability (2014)

¹⁷ Machinokoshi Energy (2024)

¹⁸ Science News (2023)

¹⁹ International Renewable Energy Agency (2023) – processed by Our World in Data

²⁰* based on data from Japan for Sustainability (2014) and Ministry of Energy and Petroleum – State Department for Energy – Kenya (2023)

²¹– JOGMEC – Japan Organization for Metals and Energy Security (No date given)

²² – Renewable Energy Institute (2018)

<Example sentences>

2. constant (~)/ constantly　~
■ My friend is constantly messaging me!
■ I work for an umbrella shop and it’s rained a lot this spring, so our boss is happy. The orders for umbrellas are constant.
■ He said he didn’t like my constant talking.

3. to lurk
■ The snake lurked under the leaves, waiting to catch any small animals that came near.
■ I think I’ll pass the science test but the thought that I might not pass it lurks in the back of my mind.

8. therapeutic / therapy
■ Having a cat is very therapeutic for my grandmother I think.
■ I know going on holiday to the countryside would be therapeutic for us but we don’t have the time.
■ If you’re really stressed you should ask the doctor about getting professional therapy.

9. circulation
■ Doing five minutes exercise after you get up will help your circulation.
■ She has bad circulation so she always wears gloves in winter.

12. to soothe ~/ soothing
■ You should put on some of this cream to soothe your arms. They look really red. I think you stayed out in the sun too long.
■ I find listening to piano music really soothing.

13. self-sufficient (in) ~
■ Two hundred years ago many people lived self-sufficient lives. They grew their own vegetables and had their own chickens and pigs.
■ My aunt and uncle have a big garden and they say they’re self-sufficient in vegetables but they say all their other food they buy at the supermarket.
■ He has big solar panels around his farm in Australia and his own private water supply so I think he can be 100％ self-sufficient if he wants to be.

16. opposition / to oppose ~
■ There has been lots of opposition to the building of the new highway.
■ Everyone is scared to oppose the manager’s idea because if you do he gets very angry!

19. a hindrance / to hinder ~
■ It took us a long time to climb the mountain. We were hindered by the strong wind and rain and the fact that the GPS wasn’t working.
■ My British friend works in Spain but she can’t speak Spanish and it hinders her progress she said.
■ Can I stay with you in your house for 5 weeks? I promise I won’t be a hindrance.😁

20. restriction / to restrict ~
■ It’s not east to travel to that country. There are many restrictions.
■ Some people have to look after their parents when they become very old and it restricts their freedom.

21. to ease ~
■ I got a new job and it’s eased my worries about the future.
■ Entry restrictions into foreign countries were eased when the number of Covid cases decreased.

22. quadruple / treble (triple) / double
■ The football player’s pay quadrupled when he moved to the team in England.
■ I really wanted the jacket on the Internet auction so I trebled my first bid.
■ She’s a taxi driver and she likes it when it rains because the number of customers usually doubles compared to a day with no rain.

24. compensation / to compensate ~
■ The driver who hit the cyclist had to pay her €800 in compensation.
■ My aunt’s house was damaged in the typhoon and she doesn’t know if she’ll get any compensation.
■ I’m sure the airplane company will compensate us but I don’t know when. We had to stay at the airport for two nights because our airplane was suddenly cancelled.

26. an entrepreneur
■ Bill Gates is a famous entrepreneur.

27. to generate ~
Generate is a difficult word to use. Generate is often used before the word energy or electricity. Other words it is often used before are words such as idea, discussion, interest and profit.

■ My sister says her family can generate all the electricity they need using only the solar panels on their roof.
■ She did a TikTok video to help generate interest in her new song.
■ Our boss wants us to have a meeting tomorrow to help to try to generate some new ideas.

29. to make a profit
■ It’s a good company. It doesn’t just think about making a profit. It treats its workers well.
■ That restaurant pays a lot of rent so they need many customers to make a profit.

30. conservative
■ Our company is so conservative. Everybody has to wear a suit, even in summer.
■ The image is that older people are more conservative. Do you agree?

31. innovation / innovative
■ We don’t care if you went to university. We want innovation! If you can show us you have some innovative ideas you can come and work with us.
■ They went to the design show again this year and they said there were many innovative designs as usual.

■ If you’ve been to different onsens before did you feel the water was different?

■ Have you prepared things in case an earthquake comes?

■ Do you have any hot springs in your area?

　 ■ When you think of renewable energy what energy do you think of?

■ I find ~ therapeutic. ~

■ Do you do anything to improve your circulation if you’re cold?

■ When you think of geothermal energy do you have any image of somewhere in the world?

■ Imagine if you were an entrepreneur. What type of business could you imagine doing?

■ I’ve assembled ~ before. ~

1. Bathing means being in water to relax or clean yourself.
2. Constant means that something is always there. It doesn’t go away.
3. If something is lurking it means it is waiting somewhere where people can’t see it. It is waiting to do something bad.
4. In this sentence a fault is a big break under the surface of the earth.
5. Magma is hot, liquid rock inside the earth.
6. In this sentence source means the place that something comes from. It is the place where something starts.
7. Centuries means hundreds of years.
8. In this sentence therapeutic means something that helps someone relax or helps someone feel better, both mentally and physically. Therapeutic is the adjective for therapy.
9. In this sentence circulation means the movement of a liquid in a closed system. In this sentence it means the movement of your blood around your body.
10. In this sentence your joints are the places in your body where your bones are connected.
11. Rheumatism is a medical problem. It is when your joints are painful. This problem affects older people more than younger people.
12. Something that soothes a part of your body makes it feel less painful. Something that soothes your mind makes you feel calmer, more relaxed.
13. Tidal is the adjective for tide. The tide is the regular rising and falling of the sea that you can see at the seaside.
14. In this sentence biomass means things such as plants that are dead that are burnt to produce energy.
15. To generate something means to create or produce it. The word generator – a machine that produces electricity – is based on the word generate. The word ‛generate’ is particularly used alongside ‛energy’ to mean ‛make energy’.
16. Being self-sufficient in something means you can produce it by yourself. You don’t need help from other people to make it.
17. In this sentence opposition means being strongly against something. You want to stop that thing.
18. A power plant* is a building that produces electricity.
19. Geologists are people who study geology. Geology is the study of rocks on the earth’s surface.
20. Restrictions are rules that limit people from doing something. Restrictions control your behaviour.
21. To hinder something means to make it difficult to happen.
22. In this sentence to ease the restrictions means to make them more relaxed.
23. If something quadruples it becomes four times bigger. For example if the number of people visiting a doctor quadruples it goes from 30 people to 120 people. If something trebles or triples it gets three times bigger and if it doubles it means it get two times bigger.
24. Legal the adjective for law. Law means the rules of a particular country or group.
25. In this sentence to compenaste someone means to pay that person money or give them something to say sorry for a problem that you have caused.
26. The local people are the people living in that area.
27. An entrepreneur is someone who starts a new business especially when there is a risk it won’t succeed.
28. A turbine is a machine which uses mainly water, steam or gas to turn around and create power.
29. In this sentence to ‛make a profit‘ means to get money from doing something.
30. Someone who is conservative doesn’t like change. That person doesn’t like to accept new ideas.
31. In this sentence stronghold means an area that gives the government a lot of support. Many people in that area vote for the government.
32. Innovative means new and original. It has a positive meaning.
33. In this sentence assemble means to put together different parts to make a bigger thing.