Insight into clean energy technologies

Filings increased 64.8% over the past decade in the field of electrical machinery, apparatus, energy. This makes it the fastest growing of all 35 technology fields at the European Patent Office (EPO) for the period since 2015. Growth in the field is largely driven by the rapid rise of inventions in areas such as batteries and smart grid technologies. The field saw the steepest overall increase in filings of any given year in 2022 (+15.6%), after the European Climate Law entered into force in 2021. This legislation aims to ensure that all EU policies contribute to the goal of climate neutrality in the EU by the year 2050.

Many of the field’s cleantech inventions have the potential to contribute to meeting this all-important target. As the roll out of clean energy and electrification accelerates, demand for electric mobility grows and the energy transition advances. The Clean Industrial Deal is one of several recent measures to support competitiveness in areas ranging from energy-intensive industries such as steel and chemicals, to waste reduction and renewable energy.

These measures follow on from last year’s major reports on European competitiveness published by Enrico Letta in April and Mario Draghi in September, both of whom highlight energy sector innovation as an absolute priority. Yet this is a field in which applicants from Asia have not merely caught up with those from EPO states. Asian applicants now dominate, particularly in battery technologies, where inventions accounted for more than two-fifths of all patent applications in the field in 2024.

The field also saw the greatest growth of the top ten technology fields at the EPO last year (+8.9%). In terms of the lead countries of origin, Switzerland (+21.3%) and the UK (+14.9%, to exceed 300 filings) were the growth champions among EPO states, though they were outstripped by P.R. China (+32.2%), R. Korea (+15.8%) and Japan (+12.9%, to exceed 2 000 filings).

Three of the field’s top ten applicants are specialist battery manufacturers, following the entry into the ranking of Amperex Technology Limited (ATL) and Eve Energy. They displaced two leading European applicants of 2023, ABB and Robert Bosch, leaving Siemens as the only remaining European applicant in the top ten.

Contribution of university research to the renewable energy landscape

Alongside the larger top applicants, universities also play a key role in clean energy innovation, including when it comes to upscaling offshore wind power capacity. The FLASC hydro-pneumatic energy storage system, developed by Tonio Sant, Daniel Buhagiar and their team, stores excess wind-generated electricity as hydraulic power, offering a solution to this renewable source’s vulnerability to intermittent winds.​ 

FLASC was developed during Buhagiar’s PhD in offshore wind, hydraulic transmission and energy storage at the University of Malta. The university recognised the potential of the work and encouraged the inventors to patent their invention, providing support throughout the process. In 2024, the inventors were European Inventor Award finalists in the Research category.

For more on the role of European universities in patenting and innovation, see the EPO’s recent joint study with the Fraunhofer Institute for Systems and Innovation Research. Among this publication’s case studies is a spin-out specialising in sensor and measurement solutions for wind turbines. Additional technology transfer and innovation case studies can be found in our dedicated learning resources area.

The rapid rise of battery technologies

Battery technologies, a key area for the energy transition, grew even faster in 2024 on the previous year (+24.0%) than they did in 2023 (+20.3% on 2022). This followed something of a breakthrough year in 2022 (+42.2% on 2021).

The top ten applicants are all Asian, accounting for 55% of patent applications in the area, with only three European companies in the top 15 and US applicants entirely absent. Taken together, EPO states still rank third in this area though, behind Korea with a share of filings almost twice as large, and China, which for the first time in 2024 edged ahead of the EPO states by a narrow margin.

E-mobility is a clear driver of growth in battery technologies, with several applicants among the top 15 being car manufacturers or suppliers of batteries to the automotive sector. Further, e-mobility is one of several factors that is accelerating innovation in grid technologies, along with increased demand for electricity across areas such as industrial consumption, cooling, data centres and AI.

Global surge in patents for enhanced electricity grids

Europe’s grids are an indispensable element for progressing towards a net zero energy system. The need to modernise and expand energy transmission and distribution infrastructure is driving innovation, as shown in the fourth and most recent joint study by the EPO and the International Energy Agency (IEA). Patents for enhanced electricity grids reveals a surge in inventions globally, with AI-related grid technologies having grown sixfold since 2018. For more on the impact of AI across industry sectors, see this year’s Patent Index feature on computer technology.

Decarbonising transport: advances in e-mobility

Advances in e-mobility are also driving growth in the field of transport, as other more traditional areas of innovation level out or decline. In 2024, the volume of inventions relating to electric propulsion increased 16.5% on the previous year. 

While transport is a field in which applicants from EPO states dominate, accounting for 57.3% of all filings at the EPO, the table of top applicants is led by US aerospace and defence company RTX, with Airbus not far behind. The pursuit of cleaner aviation fuels is another key area of clean energy innovation.

Focussing in on the top applicants in e-mobility, the diversity of applicants becomes greater still, with two of Asia’s technology conglomerates joining traditional car manufacturers and leaders in the field of batteries. Japan’s Kubota also makes the top ten this year, showing that few sectors are left untouched by the energy transition, including agriculture.

From startup to the world’s leading manufacturer of graphene-based supercapacitors

Supercapacitors are used for very fast charging and discharging applications in electric vehicles or grid management. Skeleton Technologies in Estonia begun life as a startup that developed, manufactured and sold supercapacitor energy storage cells, modules and systems.

Skeleton’s breakthrough innovation tweaks the properties of a carbon material called curved graphene, which significantly enhances the power and energy density of supercapacitors. Established in 2009, the Estonian company has built a robust intellectual property portfolio to protect its technology throughout the value chain. For more on this case study, see the recent joint study by the EPO and the European Investment Bank on the financing and commercialisation of cleantech innovation, as cited by European Commission President von der Leyen at this year’s launch of the EU’s Clean Industry Deal.

Discover more startups in the EPO’s Deep Tech Finder

Most startups specialising in grid technologies are located in Europe or the US. Over a third of the 1 085 startups identified in the cohort for the recent joint EIA-EPO study on electricity grids have filed a patent application (37%), compared to a baseline of 6% of European startups with patent applications. Many of the European startups in this area can be found in the EPO’s Deep Tech Finder, which blends patent information with business data to help investors identify Europe’s most promising startups. Overall, in 2024, SMEs accounted for 22% of patent applications among European applicants at the EPO.