"Hot spring power generation" too!

Decarbonization with energy sleeping underground December 1, 17:52

Greenhouse gas that causes global warming.

Energy fields such as power generation account for most of the emissions.

Solar and wind power are well known as renewable energies that are indispensable for the realization of decarbonization, but in fact, there are energy sources under the ground.

That is "geothermal".

Geothermal power generation is attracting attention as a promising resource, and is spreading all over the world in various forms such as “hot spring power generation”.

(International Department Reporter Misaki Fujii)

Geothermal power generation attracting worldwide attention

In late October, the World Geothermal Conference was held in Iceland, Northern Europe.

It is one of the largest in the world where the latest technologies and research results related to geothermal power generation will be shown.

This was the first time in six years that the event was held for the first time in six years, and about 2,000 people from organizations, companies, and universities from all over the world, including Japan, participated, demonstrating the expansion of geothermal power generation efforts around the world.

Following this, at the United Nations Climate Change Conference COP26 held in the United Kingdom in November, efforts to gradually reduce coal-fired power generation will be accelerated, and renewable energy including geothermal power generation will be accelerated. The result is that it becomes even more important.

What is geothermal power generation in the first place?

What is geothermal power generation in the first place?

It is power generation that uses underground heat as energy.

When rain or river water enters the basement, the heat of the bedrock around the magma chamber turns it into steam or hot water.

Of these, the ones that can be used for power generation are those that are heated at high temperatures and slowly flow deep underground for a long time to have a large amount of energy.

Geothermal power generation is a mechanism that digs a well to extract such high-temperature steam and turns a turbine to generate electricity, and it is a major feature that it does not emit greenhouse gases.

In fact, Japan is a geothermal powerhouse

Japan has hot springs all over the place.

In fact, it is called a geothermal resource powerhouse.

Its resources are the third largest in the world after the United States and Indonesia, and it has the potential to become the world's energy superpower in the field of geothermal power generation.

On the other hand, in terms of the amount of power generation equipment installed, it remains the 10th largest in the world.

Most of the heat sources are located in national parks, etc., and development has been severely restricted by law.

Nevertheless, Japan plays a major role in the world's geothermal power generation.

"World share 60%".

Japan's share of the world's turbines for geothermal power generation.

As a geothermal powerhouse, it has been under development from early on, and its technology is being used in geothermal power generation around the world.

Indonesia to triple power generation

One of these countries is Indonesia.

It is the second largest geothermal resource country in the world, and large-scale equipment was originally introduced and the utilization of geothermal power generation was progressing.

However, in areas centered on remote islands in the eastern part of the country, where the population is small, diesel power generation, which can be introduced relatively easily, was the mainstream.

Now, there is a growing momentum to expand geothermal power generation to these areas as well.

There is a need for small-scale geothermal power generation on remote islands, and the number of inquiries to Japanese manufacturers who develop it is increasing.

Small generators have the advantage of being relatively inexpensive to install and shortening the time to operation.

You can never expect a large amount of energy with one unit, but installing multiple units in each region will lead to a certain amount of energy supply.

In addition, easy transportation is also an important point in areas with many remote islands.

Indonesia plans to increase new construction and triple geothermal power generation by 2028.

Demand is also in Africa

Momentum for geothermal power generation is also increasing in Africa.

For example, Ethiopia.

Currently, the fighting between government forces and ethnic minorities continues and the domestic situation is tense, but the population exceeds 100 million and is the second largest in Africa, and high economic growth is expected.

However, the supply of electricity that supports growth is less than half of the required amount.

Hydroelectric power generation using the Nile is concerned about friction with neighboring countries, and it is not easy to import electricity from overseas.

Under these circumstances, Ethiopia is looking for domestically produced and stable energy, and geothermal power generation that can utilize underground resources is promising.

I have little experience in geothermal development so far.

For this reason, Japan's JICA = Japan International Cooperation Agency and others are embarking on development support.

In addition, Toshiba, which handles turbines for power generation, received an order for a geothermal power generation business in Ethiopia last February.

We are planning to introduce a small power generation facility.

First of all, we would like to accumulate know-how locally and use it for the development of large-scale geothermal power generation in the future.

Mr. Kawasaki

"Due to the trend of decarbonization, expectations for geothermal energy are increasing even in countries and regions where there has been no demand until now. Unlike solar and wind power, it is not affected by the weather, so in many countries and regions. It will continue to attract attention in the future. We would like to proceed with development even in places where the amount of geothermal resources and site area are limited. "

There is a possibility that "hot spring power generation" will spread to the world.

As the demand for geothermal power generation increases around the world, the utilization of "low temperature" geothermal resources is also advancing.

In the past, high-temperature steam and hot water were required for power generation, but even at lower temperatures, pentane and ammonia with a low boiling point can be heated, and the steam can be used to turn a turbine. You will be able to do it.

This method is also called "hot spring power generation" because it can be used with hot water as hot as a hot spring.

It has spread mainly in the United States since around 2010, and has been introduced in Japan, a hot spring powerhouse.

In addition, it is being used more widely in areas where geothermal resources have not always been abundant.

For example, Germany is aiming to expand low-temperature geothermal power generation by introducing a feed-in tariff system for electricity.

Fuji Electric, which develops turbines for power generation, is required to respond to this trend as a Japanese company that has supported geothermal power generation around the world.

Mr. Koyama

"Whether there are high-energy geothermal resources depends on the location, so it is necessary to consider whether the high temperature or low temperature method is suitable for each location. Is required "

Will it spread in Japan?

Japan has supported the development of geothermal power generation in the world.

Now, the development of new technologies that have not been put into practical use in any country has begun toward the expansion of geothermal power generation.

The photo is a survey conducted by NEDO = New Energy and Industrial Technology Development Organization at a geothermal power plant in Hokkaido in July.

Check the shape of the underground by sending seismic waves.

The aim is to search for ultra-high temperature water close to magma and obtain stronger energy than conventional geothermal power generation from it.

While the average depth of the conventional method is about 2 km, this method called supercritical geothermal is more than 3 km.

Since water at around 400 ° C, which is close to magma, is used as an energy source, enormous energy can be expected at only one location.

The important point is that a large amount of energy can be efficiently extracted even if the development area is small.

Even in Japan, where geothermal power generation has not spread easily due to concerns about the impact on national parks on the ground despite its abundant resources, it can be expected that it will be utilized by a new method.

The concept is the exact opposite of "small size" and "low temperature", which require less energy per location, but they all have in common that they are trying to expand the possibilities of geothermal utilization.

Mr. Kato

"I think this is one way to promote geothermal development in national parks with environmental protection in mind. After evaluating the economic efficiency, it will spread in Japan around 2050. I want to let you

With the trend of decarbonization intensifying, the global geothermal power generation market is estimated to exceed $ 50 billion by 2027.

As the market expands, geothermal power generation is expanding into areas that were previously considered difficult to introduce through a wide range of methods, including "miniaturization," "low temperature," and "ultra-high temperature." ..

Since there is a possibility that the shape of energy will change drastically, it is becoming more important to know how geothermal heat will permeate the world and spread in Japan.

International Department Reporter

Misaki Fujii

Joined in 2009

After working at Akita Bureau, Kanazawa Bureau, and Sendai Bureau

, covered energy issues of

the International Department.