Global green technology patent families grew nearly fourfold between 2003 and 2023, rising from approximately 111,400 to 412,300 – a compound annual growth rate of 6.8% (see Figure 1). Growth was modest in the early period before accelerating from 2010 onward, peaking at 18.3% in 2016, with a brief contraction in 2019 followed by a strong rebound in 2020. The expansion was highly concentrated: three technology fields alone – smart energy, grid and transmission; energy storage (batteries); and air pollution control – accounted for half of total growth over the period. Green technology's share of total patenting also rose, from 13.7% in 2003 to 18.2% in 2023, despite a temporary dip in 2013–2015 when a surge in overall global filings – largely driven by China – temporarily outpaced green technology growth. Notably, the share jumped sharply during the 2008-2009 financial crisis as overall filings contracted while green technology patenting continued to grow. Taken together, these trends indicate that green technologies have grown not only in absolute terms but also in relative importance within global innovation activity – a particularly notable finding given that total world patent families more than tripled over the same period.
The distribution of green patent families across sectors reveals a clear and evolving pattern, with energy efficiency, conversion and storage reinforcing its position as the dominant sector – increasing its share from 36.2% in 2003–2005 to 42.2% in 2021–2023, the largest shift of any sector over the period (see Figure 2). Strikingly, this gain of 6.0 percentage points is almost mirrored by the decline in clean energy, which fell from 26.0% to 19.4% over the same period, suggesting a structural shift within green patenting from energy generation toward energy efficiency, conversion and storage technologies. Pollution control, recycling and water treatment remained broadly stable, with its share declining only marginally from 28.0% to 27.1%, retaining its position as the second-largest sector. The smaller sectors – agriculture, forestry and industry, and sustainable mobility – together accounted for around 11.3% of total patent families in 2021–2023, while sustainable mobility recorded a modest increase from 4.2% to 5.0%, suggesting an emerging but growing contribution.
Over the period 2021–2023, green technology patenting remained highly concentrated, with the top three fields – smart energy, energy storage (batteries), and air pollution control – together accounting for 41.8% of all global patent families (see Figure 3). Smart energy, grid and transmission (15.5%) and energy storage (batteries) (13.8%) together accounted for nearly three in 10 global green technology patent families, with both fields having more than doubled their shares compared to 2003–2005. Air pollution control, previously the top-ranked field at 14.7% in 2003–2005, slipped to third place with a share of 12.5%. Beyond the top three fields, wastewater and sewage treatment made modest gains, rising from 7.3% to 8.1%, while solar energy (6.8%) and bioenergy (5.2%) remained significant contributors, yet saw their combined share contract from 16.8% to 12.1%.
In terms of fastest growing fields, smart energy, grid and transmission recorded the largest increase in share between 2003–2005 and 2021–2023, rising sharply from 6.2% to 15.5% (see Figure 4). This was followed by energy storage (batteries), which gained 7.0 percentage points. Perhaps most strikingly, EV charging infrastructure – effectively a new field with just two patent families in 2003–2005 – emerged rapidly to record 16,362 families and a 1.4 percentage point gain, while wastewater and sewage treatment added 0.8 percentage points.
In 2023, China dominated green technology patenting with an overwhelming 71.9% share of global green patent families, followed by the Republic of Korea (8.3%), Japan (6.9%) and the US (4.3%), while European nations each accounted for less than 3.0% (see Table 1). This distribution reflects a profound structural transformation: in 2003, Japan held 45.0% of all global green patent families and China a mere 7.8%. The near-complete reversal of this order over two decades is largely attributable to China’s exceptional average annual growth rate of 19.3%, far outpacing all other origins. Indeed, China accounted for approximately 95.7% of all net growth in global green patent families between 2003 and 2023 – meaning the global expansion in green technology patenting over this period was, in effect, driven almost entirely by a single origin.
While China dominated in absolute terms, Denmark led among the top 15 origins in green technology intensity, with 33.9% of its total patent families classified as green technologies (see Figure 5). Poland (28.2%), Austria (23.9%), Germany (23.7%), France (23.3%) and the Republic of Korea (22.2%) also demonstrated a strong strategic focus on green innovation relative to their overall patenting activity – all above the global average of 18.2%. In contrast, the US recorded the lowest green intensity among the top 15 origins at 12.6% – notably below the global average – alongside comparably low figures for Switzerland (15.3%), the UK (15.4%) and Japan (15.5%).
The Relative Specialization Index (RSI) captures the degree to which a country's patenting activity in a specific green technology is proportionally greater or smaller than its overall patenting activity. A positive RSI signals above-average specialization in a given technology relative to the country's total innovative output, while a negative RSI indicates a comparative disadvantage. Figures 6 to 10 show the RSI of the leading technology within each of five green sectors: solar energy; smart energy, grid and transmission; electric vehicles (EV), air pollution control; and biopesticides and biocontrol.
Solar energy shows the most heterogeneous specialization pattern among the five technologies (see Figure 6). Singapore stands out with the highest RSI (0.54), reflecting a concentrated and disproportionately strong patenting footprint in this domain relative to its overall innovation portfolio. Among the other top 15 origins, Israel (0.19), the Kingdom of the Netherlands (0.17), the Republic of Korea (0.13) and Austria (0.12) record meaningful positive RSI values, suggesting a strong focus on solar innovation. Smart energy, grid and transmission technology presents a strikingly uniform picture: all countries in the sample, except China, record negative RSI values (see Figure 7). This technological field is dominated by China, which accounted for 82% of all patent families in this field during the period 2021–2023.
Electric vehicles show the widest dispersion of RSI values and reveal a clear geographical divide (see Figure 8). Sweden (0.75) and Germany (0.65) top the rankings by a substantial margin, reflecting the deep integration of EV-related innovation. France (0.47), India (0.44) and Italy (0.38) also record high positive RSI values.
In air pollution control technology, Saudi Arabia (0.40) and the Russian Federation (0.33) record the two highest RSI values, while the US (0.20) and the UK (0.15) also show positive specialization (see Figure 9). Biopesticides and biocontrol display the strongest concentration of high RSI values, led by Brazil (0.80), Israel (0.79) and India (0.74) (see Figure 10).
No country dominates across all five technologies. Specialization patterns are highly sector-specific, suggesting that green technology innovation systems are fragmented rather than cumulative. Large absolute patent volumes do not necessarily imply positive RSI, while niche and emerging economies show strong relative specialization. Targeted industrial strategies or structural economic conditions can generate strong revealed specialization in specific green technologies, as seen in Singapore in solar energy, Sweden in EVs, and Brazil and Israel in biopesticides