Global patent trends in energy storage
Why it's not a waste of energy

The shift in recent years towards using renewable sources of energy to make up a larger proportion of the global energy supply, along with the intermittent nature of many renewable sources of energy, has highlighted the critical importance of effective energy storage.

With this shift, we are seeing that companies within the energy storage sector are safeguarding their R&D efforts by investing heavily in intellectual property, particularly patents.  This paper explores global patent trends in energy storage.

Growth and Global Distribution of Patent Publications in Energy Storage

Figure 1 shows the number of patent publications each year between 1996 and 2016 in three key energy storage sectors: thermal energy storage, electro-mechanical energy storage and electro-chemical storage.

Figure 1: Patent publications per year by sector

Figure 1 shows a significant increase in the number of patent publications in these energy storage sectors between 1996 and 2016. Whilst the number of publications in electro-chemical, electro-mechanical and thermal storage have all demonstrated growth, it is interesting to note that surges in installations occurred at different times within the different sectors. The electro-chemical sector experienced a boom around 2010, a time at which significant advances were made in battery technology, and particularly in high-power lithium-ion batteries which are often useful in hybrid vehicles or for stabilising the electric grid. Similarly, the number of publications in thermal storage increased between 2008 and 2013, a period in which important new technologies, such as cryogenic storage and ice-based storage, were introduced to the market.

What about the global distribution of patent publications? Figure 2 shows the number of patent publications in each country by sector over the same time period as Figure 1.

Figure 2: Patent publications per office by sector

Figure 2 shows that patent publications are heavily focused on China, the USA, Europe and Japan, a trend which is mirrored in most industries. These countries/regions are generally considered the most valuable markets for many companies and, consequently, a large number of patent applications are filed in these offices.

Growth and Global Distribution of Energy Storage Installations

Now that the growth and global distribution of patent publications in energy storage have been explored, it is interesting to consider whether the growth and global distribution of energy storage installations follow similar patterns. Such analysis gives an indication as to whether energy storage companies have been investing in intellectual property in territories that have demonstrated a growth in the number of energy storage installations.

With this in mind, Figure 3 demonstrates the growth and global distribution of energy storage installations across electro-chemical storage, electro-mechanical storage and thermal storage platforms.

Figure 3: Extract from the US DOE Storage Database

The similarities between the graphs of Figure 1 and Figure 3 are striking. The growth in the number of patent publications in thermal storage from 2008 onwards, shown in Figure 1, is very much mirrored in Figure 3. Similarly, Figure 3 exhibits an increase in the number of electro-chemical installations from 2010 onwards, which follows the trend in patent publications shown in Figure 1.

The fact that the graphs of Figure 1 and Figure 2 exhibit such similar trends suggests that energy storage companies are recognising the value of their research and development in a growing sector, and are investing in intellectual property to safeguard their innovation in later years.

The map shown in Figure 3 demonstrates the global distribution of energy storage installations across the same sectors as the graph. Again, patterns differ from sector to sector. Electro-chemical installations are fairly well-spread across the globe, although we do see noticeable clusters of electro-chemical and electro-mechanical installations in the USA and Western Europe where such storage solutions can provide a reliable and robust response to rapid surges in demand resulting from a high population density. Electro-chemical installations are also prominent in the Far East.

In contrast, thermal installations are mainly found in locations which lend themselves well to intermittent environmental sources of energy (e.g. solar, wind, tidal). Clusters can be seen in South America, South Africa and Southern Europe where population densities are lower and where powerful natural energy resources can be harnessed.

However, whilst the graph of Figure 3 mirrors the trends shown in Figure 1, the map of Figure 3 contrasts significantly with Figure 2.

Figure 3 suggests that geographical locations of installations within each sector have been chosen to match attributes of a system with particular local requirements, or to take advantage of local environmental factors. In contrast, Figure 2 shows that patent publications are heavily focused on the USA, Europe, Japan and China, a trend which is mirrored in almost every other industry and which does not follow the individual character of the global distribution shown in Figure 3.

There are a number of possible reasons for this. Firstly, historically, innovative companies have often held a view that enforcement of intellectual property rights in some countries which may have a less sophisticated patent system is very difficult. However, we are seeing that many countries are making significant efforts to improve their patent systems and make enforcement a realistic possibility. In any event, even in countries in which enforcement is challenging, intellectual property rights can still act as a useful deterrent to rival companies looking to enter the market.


The long lifespan of a patent also raises the need for innovative companies to forecast where their products may become valuable in years to come to ensure that opportunities for obtaining valuable geographical protection are not being missed

There may also have been a view from within the industry that patent protection is more difficult and/or expensive to obtain in countries in which protection is sought less frequently. However, our experience in filing large global families of patent applications is that this is not the case and, in fact, broader protection can often be obtained in some of the less common states. Additionally, it is important to remember that a patent can usually last for 20 years from its filing date and, therefore, the value of a patent and opportunities for enforcement can grow substantially during its lifetime. The long lifespan of a patent also raises the need for innovative companies to forecast where their products may become valuable in years to come to ensure that opportunities for obtaining valuable geographical protection are not being missed.

Of course, the USA, Europe, Japan and China might represent important markets or manufacturing hubs for a given innovation, in which case it would clearly be prudent to pursue patent protection in these countries. Based on the global growth and distribution of energy storage installations shown in Figure 3, however, it does appear that opportunities exist for obtaining valuable intellectual property rights in countries which might be thought of as having less sophisticated patent systems. Patent protection in areas of particular commercial interest can be instrumental in obtaining and maintaining market share and in acting as a deterrent to keep competitors off the market. It can also be a useful licensing tool.

For example, Figure 3 shows that South Africa is a hub of activity in the thermal storage sector, but this is not reflected in the number of thermal storage patent filings in the country. South Africa has a cost-effective and well-organised patent system. A South African patent can be registered based on a granted patent in another jurisdiction (e.g. Europe, USA), meaning that the time and expense typically associated with patent prosecution in most jurisdictions can be avoided. As a result, patent protection in South Africa can be obtained relatively cheaply and quickly.

We also see activity in the thermal and electro-chemical sectors in India. Traditionally, many companies and observers have held the view that Indian patents are very hard to enforce. However, in recent years, the Government of India has made significant efforts to improve the quality of the Indian patent courts, and a number of important decisions have been passed down as a result.

North Africa features heavily in the thermal storage sector. Until recently, none of the northernmost countries in Africa has been a member of any regional patent system (Africa has two regional patent offices: The African Regional Intellectual Property Organization (ARIPO) and Organisation Africaine de la Propriété Intellectuelle (OAPI)). This has meant that patent protection in Morocco, Algeria, Libya and Egypt, for example, could only be obtained by filing a separate application in each country. However, Morocco (since 1st March 2015) and Tunisia (since 1st December 2017) are now validation states of the European Patent Office, meaning that patent protection in Morocco and Tunisia can be obtained via a European patent application, and this patent protection will have the same effect as national Moroccan and Tunisian patents. Therefore, companies for whom Morocco or Tunisia are an important market can make use of their European patent applications to obtain patent protection in these states.


In summary, we have noticed that some countries or regions that host significant activity in the energy storage sector have been ignored by companies in the sector when it comes to filing patent applications. Armed with knowledge and expertise relating to the nuances of patent law in these jurisdictions, and connections with high-quality local patent attorneys, valuable patent protection could be obtained that could give companies an important foothold in these territories. It will be interesting to see whether these trends continue as more recent data becomes available.

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