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The Green Transformation Technologies Inventory (GXTI)

The Green Transformation Technologies Inventory (GXTI) is a technologies inventory which gives a bird’s-eye view of technologies related to Green Transformation (GX) published by the JPO in 2022. It also includes the patent search formula linked to each technology category.

The GXTI illustrates how to categorize GX technologies and how to search for patent documents which include a category of GX technology.

It is expected that the GXTI will become a useful common asset for companies to make evidence-based analyses of GX technologies based on the patent information and to make necessary disclosures of their climate change related information.

GXTI(GX Technologies Inventory)

Background to the Creation of the GXTI

The technologies inventory was developed after two rounds of discussions (6 January 2022 and 6 April 2022) by a panel comprised of six external experts with in-depth knowledge of GX technology.

In addition, the comprehensive patent search formula linked to each technology category was prepared by patent examiners in each field.

Members of the Expert Panel (in alphabetical order, titles omitted)

Keigo AKIMOTO Group Leader/Chief Researcher, Systems Analysis Group, Research Institute of Innovative Technology for the Earth
Koji OYAMA Fellow, Center for Research and Development Strategy, Japan Science and Technology Agency
Michihisa KOYAMA Professor, Research Initiative for Supra-Materials, Shinshu University
Kenji TANAKA Associate Professor, Department of Technology Management for Innovation, Graduate School of Engineering, The University of Tokyo
Hideyuki DOHI

Executive Officer, General Manager of Energy Technology Research Dept., ENEOS Research Institute, Ltd.
(Formerly, Director General, Environment and Green Chemistry Unit, Technology Strategy Center, New Energy and Industrial Technology Development Organization)

Takao NAKAGAKI Professor, Faculty of Science and Engineering, Waseda University


Observers of the Expert Panel

  • Energy and Environment Innovation Strategy Office, Industrial Science and Technology Policy and Environment Bureau, Ministry of Economy, Trade and Industry
  • Office of Global Environment and Decarbonizing Innovation Research, Global Environment Bureau, Ministry of the Environment

The structure of GXTI

Hierarchical Structure of Categories

The GXTI consists of three levels of hierarchy as follows:

Level 1 (comprises 6 large categories)

Level 2 (comprises 32 medium categories)

Level 3 (comprises 86 small categories)

The symbol for each category starts with “gx”.

figure:Hierarchical Structure of Categories

Level 1 Category

The Level 1 Category consists of five perspectives: (1) energy supply(gxA), (2) energy demand(gxB), (3) energy storage(gxC), (4) CO2 reduction in non-energy sectors(gxD) and (5) capture, storage, utilization and removal of greenhouse gas(gxE).

A separate set of four transversal perspectives(gxY) is also provided in the Level 1 Category. The four perspectives are “control-related technology”, “measurement-related technology”, “business-related technology” and “ICT-related technology”. GxY is the cross tabulation of these four perspectives and five GX technology categories, gxA to gxE. In other words, the number of patent documents in gxY is an inner number of the number of patent documents in gxA-gxE. GxY can be used to identify trends in GX technologies which include each of the transversal perspectives. ("Energy Supply X Control and Coordination", for example)

Level 2 Category and Level 3 Category

In the Level 2 Category and the Level 3 Category, important individual technologies in each Level 1 category are listed.

In the GXTI, the Level 3 Category illustrates what specific technologies are involved in the Level 2 Category, and analyses of patent application trends are expected to be conducted by the unit in the Level 2 Category. It is also possible, of course, to make analyses by the units in the Level 3 Category.

In some cases, a patent document might involve multiple technologies listed in the Level 2 and/or the Level 3 Category. Since the Level 3 Category was created with the principal aim of linking each category with a patent search formula, the technical granularity differs by the category. Some Level 3 Categories in the same Level 2 Category are conceptually overlapped.

Patent Search Formula

The GXTI contains the patent search formula linked to each small category. A patent search formula consists of either International Patent Classifications (IPCs) or a combination of IPCs and texts. Using the formula, it is possible to search for patents corresponding to each category of technology in the Level 3 Category and the number of the patents.

figure:Patent Search Formula of solar

figure:Patent Search Formula of hydrogen

In case of searching for all relevant patents in the Level 2, the Level 1 or the whole GXTI, all the patent search formulae in the Level 3 category under that category must be added up. (By taking the union set)

The basic rule is to use English text. (The "Survey by the JPO" described below will also use the International Patent Classification x English text.) However, Japanese text is also available as a reference in case you wish to search using Japanese text.

Also, for the convenience of users of J-PlatPat(External link), which is a free database of patent information including official gazettes of patents for search and reference, the GXTI provides patent search formulae specific to the search by “Logical Expression Input” on J-PlatPat. The patent search formulae are not only valid for J-PlatPat but also in other commercial patent search databases. (Please change the format of search formulae according to the rules of each database.)

Since the International Patent Classification is used not only in Japan but also in patent documents worldwide, the patent search formulae in the GXTI can be used for worldwide patent document search.

Note: Japanese texts are used to search Japanese patent documents in J-PlatPat.

Note: Because of the 500-character limit on J-PlatPat's logical formula input, it may be necessary to split the patent search formula into separate searches if it is long.

Utilization of the GXTI

Following the revision of Japan’s Corporate Governance Code in June 2021, companies listed on the Prime Market in Tokyo Stock Exchange New Market Segments are supposed to enhance the quality and quantity of their information disclosure related to climate change.

The GXTI presents an example of how GX technologies can be categorized, and how patent documents can be searched for a particular GX technology. We hope that the GXTI becomes an aid for the companies to make evidence-based accounts of their climate change related information.

With the GXTI, a company can objectively quantify their strengths in GX technology by quoting the number of their patent applications in each technology category by searching patent documents with applicant names from the company for each relevant technology category, for instance. Also, if you search patent documents with applicant names from other company, you can compare the strengths of your company in terms of GXTI technology category with other companies. In this way, the GXTI can be a useful aid for planning your business and patent strategy.

Further Plans by the JPO

Survey by the JPO

The JPO plans to conduct a survey using the GXTI to outline the trends in patent applications in each country by GXTI technology category, and to identify and disseminate evidence-based information on areas in which Japan has strengths.

In addition to visualizing the share and transition of GX technology in Japan and other countries, this survey report is also intended to be used by companies and others as a reference for analysis methods when conducting patent analysis using GXTI.

The report will be released in April or May 2023. We also plan to release the progress of the survey as needed during FY2022.

Notable Technologies not in the GXTI

The JPO is also planning to select around five to ten themes of notable technologies, such as “Energy Saving at Data Centers”, “Inventions related to CO2 Emission Trading” etc., which are not part of the GXTI hierarchical structure, and to publish them with the patent search formulae.

International Development

The JPO intends to take international initiatives and to hold discussions with intellectual property offices of the United States, Europe, China, and Korea, as well as the World Intellectual Property Organization (WIPO) regarding the effective use and the improvement of the GXTI. The GXTI will be reviewed and updated as necessary.

Call for Examples of Utilization of the GXTI

The JPO is calling for examples of patent information analysis or climate change related information disclosures utilizing the GXTI.

We will report the case studies as soon as we have received and reviewed them. We will also be happy to post links to cases that have already been published on the Internet.

Please contact us at the contact below if you wish to be listed.

Your opinion on the GXTI

We are also looking to update the GXTI in line with technological trends in GX technology etc.

Please contact us at the contact below, if you have any opinion on the technology categorization or the patent search formulae of the GXTI.

[Last updated 23 June 2022]


The JPO Policy Planning and Coordination Department,

Policy Planning and Research Division, IP Trend Research Section

Japan Patent Office

Tel:+81-(0)3-3581-1101(ext. 2155)