Equal International
Intellectual Property Regimes & Green Industrialisation · 2026

The patent walls
around the green transition.

368,266 green-technology patents. Eight jurisdictions. A handful of firms.
This is the architecture of who gets to industrialise — and who pays the toll.

Elaboração: Paulo Esteves

Part I · The Landscape

Where the green patents are — and where they are not.

The IPC Green Inventory turned WIPO's classification system into a tool for reading climate technology as property. Run that lens over PATENTSCOPE and a structure appears: heavy concentration by topic, by country and over time.

FIG 1 · Patents by topic
Source: PATENTSCOPE / IPC Green Inventory (Esteves et al., 2026)
Start with a number. The PATENTSCOPE corpus assembled through the IPC Green Inventory yields 368,266 unique green patent publications. 368,266 Deduplicated publication numbers · all topic areas · all years It is the most systematic map of who controls climate-critical technologies.
The corpus is not flat. Eight topic areas concentrate the green innovation frontier — and one of them dominates. Alternative energy production alone accounts for nearly 47 per cent of all deduplicated publications. Solar, wind, hydrogen, geothermal, biofuels — the technologies of the energy transition itself.
Volume is one story. Concentration is another. The Herfindahl–Hirschman Index, a standard competition metric, reads the country shares within each topic. Even the least concentrated topic — transportation — is dominated by a top-4 of countries that holds nearly three-quarters of the published patents. HHI > 0.25 is conventionally considered highly concentrated. Every topic in this corpus clears that bar.
Reframe the same evidence as a four-country dominance ratio. Across the eight topics, the top four jurisdictions hold between 74 and 92 per cent of all published green patents. The top ten reach 93–99 per cent. 93%+ CR4 — Combined share of the four leading jurisdictions, every topic.
CR10 — Combined share of the ten leading jurisdictions, every topic.
Who are those jurisdictions? The priority-origin field — the country of first filing — reads the geography of invention itself. China, the United States, Japan, South Korea and the European patent system recur across every topic. The rest of the world is almost everywhere a residual. India and Brazil appear in some topics. South Africa is largely absent.
And then there is one trajectory the corpus reads more loudly than any other. China's priority-origin filings across the eight topics grew from roughly 456 in 2015–2019 to 4,678 in 2020–2024 — close to a tenfold expansion in five years. ≈ 10× China's share gains are evident where the volume gains are largest:
  • Alternative energy production: from 8% to 15%;
  • Nuclear power generation: from 10% to 20%;
  • Energy conservation: from 14% to 22%.
Concentration is not only between countries; it is also reshuffling within the leading bloc. Source: PATENTSCOPE · top-6 priority origins per topic · 2015–2019 vs 2020–2024 (2025 excluded).
The corpus does not show a diversification of green innovation. It shows tightening control in the very period when developing countries need to scale these technologies.
— Reading the PATENTSCOPE corpus, 2005 → 2024
Part II · Value chains & patent distribution

Six chains. Six different patent geographies.

For each chain, three stages — upstream materials and refining, midstream manufacturing, downstream integration and use — and the firms that hold the patents at each stage. The control barometer summarises, qualitatively, how concentrated each stage is and how high the patent walls are. Sources are listed at the foot of each card and consolidated in Methods.

Chain
Comparative reading

Where each country ranks, chain by chain.

A bump chart of priority-origin rankings: each country's position in the top-5 of each chain, 2020–2024. Steep slopes mark places where a country leads in some chains but disappears in others.

Show
Source: PATENTSCOPE corpus, subtopic-filtered priority origins, 2020–2024. Countries shown: top-5 by chain. A jurisdiction absent from a chain's top-5 is drawn off the chart (rank 6+).

Note on EP. "EP" is not a country — it is the priority code assigned when an applicant files first at the European Patent Office (EPO), the intergovernmental body that grants European patents on behalf of 39 contracting states (the 27 EU members plus the UK, Switzerland, Norway and others). European multinationals frequently route filings through the EPO instead of filing separately in each national office, which makes EP appear prominently in chains where European industrial leadership is strong (notably wind energy). National European codes — DE, FR, GB, IT — capture filings that did not use the EPO route.
Over 96% of wafer output and roughly 85% of cells and modules are produced inside one vertically integrated cluster. The patent walls and the production walls are the same wall.
— On the solar PV midstream
Part III · The Geography of Value

Where the value lands, chain by chain.

Patents map control; geography maps capture. Each chain is dispersed across continents but unevenly: a different country dominates each stage, and the patent-dense stages are not the same for solar PV, wind, hydrogen, steel, EVs and the grid. Choose a chain and a stage to read the geography. Hubs are illustrative regional centres; see Methods for sources.

Chain
Stage
Coda

Six chains, six contestable openings.

Read together, the patent distribution, the chain geography and the value-share-per-stage point to different policy openings in each chain. Choose a chain to see where the wall is thinnest — and what kind of instrument tends to be effective there.

Methods & Sources

How this piece was built.

The argument in one sentence

Green industrialisation depends on access to climate-critical technologies, and the IP regime concentrates ownership of those technologies in a small set of advanced economies; but the chain-by-chain patent distribution differs substantially across solar PV, wind, low-carbon hydrogen, green steel/H₂-DRI, EVs and grid modernisation; therefore policy responses must be tailored to where the patent walls are thinnest in each chain rather than apply a uniform template.

Data

Patent records were retrieved from WIPO's PATENTSCOPE using IPC queries aligned to the IPC Green Inventory. The analytical dataset contains 368,266 unique publication numbers drawn from 451,110 merged records, grouped into the eight topic areas reported in the figures. Country-level concentration metrics — HHI, CR4, CR10 — were computed on country shares of deduplicated publications within each topic, following OECD competition-analysis practice. The priority-origin matrix in Figure 5 was tabulated from the manuscript's Table 2 (top-10 priority origins per topic; n = 66,809 publications with priority data).

Chains: IPC mapping & sources

Part II shows priority-origin patent shares (2020–2024) for the six chains, computed from the master PATENTSCOPE corpus by filtering on IPC Green Inventory subtopics:

  • Solar PV — subtopic "Solar energy" (n = 375)
  • Wind energy — subtopic "Wind energy" (n = 937)
  • Low-carbon hydrogen — subtopic "Fuel cells" as proxy (n = 640)
  • Green steel / H₂-DRI — "Carbon capture and storage" as closest proxy (n = 922)
  • EVs & green mobility — "Vehicles in general" (n = 2,639)
  • Grid modernisation — composite of "Power supply circuitry", "Storage of electrical energy" and "Measurement of electrical consumption" (n = 1,177)

The IPC Green Inventory does not separately classify Green Steel/H₂-DRI; the CCS subtopic is used because it concentrates carbon-reduction patents that overlap with low-carbon steelmaking. Hydrogen is proxied by the Fuel cells subtopic, which captures most low-carbon hydrogen patenting but not all electrolyser-specific filings.

Part III uses approximate hub locations and indicative capacity figures consistent with the IEA Energy Technology Perspectives 2023 supply-chain mapping and the Consolidated Green Industrialisation Dashboard v5 (Brazil and South Africa case studies). Hub coordinates are illustrative regional centres, not exact plant geocodes; per-stage value shares are order-of-magnitude estimates derived from IEA, OECD and industry analyses.

Limitations

PATENTSCOPE export limits mean some topic counts should be treated as lower bounds. The IPC Green Inventory is policy-relevant but not exhaustive; alternative classifications would produce different patterns. Patent counts are not measures of technological capability — only of ownership claims. Value-share estimates by chain stage are approximations from secondary sources and should be read as orders of magnitude.

Primary sources

  • WIPO PATENTSCOPE — corpus source · patentscope.wipo.int
  • WIPO · IPC Green Inventory — classification scheme
  • Rivera León et al. 2023 — WIPO Working Paper 44 · methodological reference
  • Lavopa & Menéndez 2023 — UNIDO Policy Brief 6 · concentration framing
  • OECD 2020 · 2021 — Green Innovation; Methodologies to Measure Market Competition
  • IEA 2020 · 2023 — Battery patents; Energy Technology Perspectives
  • UNCTAD 2024b — Frontier Technologies Report
  • Johnstone, Haščič & Popp 2010 — Renewable Energy Policies and Technological Innovation: Evidence Based on Patent Counts
  • WIPO 2025 — World Intellectual Property Indicators

Build

Single self-contained HTML. Vanilla JavaScript with D3 v7 for visualisations, TopoJSON for the world map, d3-sankey for the value-flow diagram, and Scrollama for scroll-step detection. Designed for WCAG 2.2 AA: skip link, visible focus, semantic landmarks, prefers-reduced-motion respected, contrast ≥ 4.5:1 for body text. Reads sensibly without JavaScript.

Citation

Esteves, P. (2026). The Patent Walls Around the Green Transition — interactive companion to "Intellectual Property Regimes and Green Industrialisation". Brighton: Equal International.