Building on the review of existing classification systems, WIPO has developed a new Green Technology Inventory for Statistical Use (WIPO-GTIS), specifically designed to address the key limitations identified: divergent definitions constraining international comparability, structural differences impeding aggregation, and accessibility barriers for users without specialized resources. The WIPO-GTIS is intended to complement, rather than replace, existing classifications, and is designed to serve as a transparent, harmonized reference framework for statistical analysis and cross-country comparison.
The classification was developed through a systematic four-stage methodology.
First, a comparative analysis of existing classifications (CNIPA, EPO, JPO, OECD and WIPO) identified areas of consensus and divergence, with technologies appearing in two or more systems designated as high-priority candidates.
Second, the resulting technology list was structured into a coherent taxonomy of 36 technology fields organized across five overarching sectors, balancing analytical granularity with usability.
Third, IPC concordances were developed for each technology field, relying exclusively on IPC codes – deliberately avoiding keyword searches, CPC tags, or jurisdiction-specific tools – to ensure accessibility, reproducibility and compatibility with any standard patent database.
Fourth, an AI-assisted quality control procedure validated the IPC mappings by assessing random samples of 100 patents per technology field; eight fields falling below a 70% relevance threshold were subsequently refined.
The result is a lean, transparent and statistically robust framework guided by four core design principles: focus on core green technologies with broad international recognition; exclusive reliance on IPC codes to democratize access; explicit optimization for macro-statistical analysis rather than patent search; and full documentation enabling accurate interpretation and future adaptation.
The WIPO-GTIS comprises five sectors and 36 technology fields.
Sector 1, clean energy, covers seven fields – solar energy, wind energy, hydropower, geothermal energy, bioenergy, hydrogen production and fuel cells, and nuclear energy – encompassing technologies that generate energy with low or zero greenhouse gas emissions.
Sector 2, energy efficiency, conversion and storage, includes eight fields spanning building envelope and HVAC, efficient lighting, efficient electrical machines, smart energy management and smart grids, efficient combustion, battery energy storage, other energy storage, and thermal energy.
Sector 3, sustainable mobility, covers eight fields addressing the decarbonization of transport: electric vehicles, hybrid vehicles, fuel cell vehicles, electric vehicle (EV) charging infrastructure, sustainable aviation, sustainable shipping, rail and public transit, and micromobility.
Sector 4, pollution control, recycling and water treatment, comprises seven fields – wastewater and sewage treatment, waste management, recycling, soil and ground remediation, carbon capture and storage, air pollution control, and bioplastics and green packaging – targeting pollution prevention, resource recovery and environmental remediation.
Finally, Sector 5, agriculture, forestry and industry, includes six fields – smart irrigation, biopesticides and biocontrol, biofertilizers and soil enhancement, forestry, low-carbon cement and concrete, and low-carbon steelmaking – addressing sustainability across primary production and key industrial sectors. Together, these five sectors capture the breadth of green technology innovation relevant to climate change mitigation and broader environmental sustainability. For further details, please refer to the full study, WIPO IPC–Green Technology Concordance: A Harmonized Classification Methodology, available at https://www.wipo.int/en/web/ip-statistics/.