The Role of Geothermal in the Green Energy Mix

12/11/2021

At the 26th UN Climate Change Conference of the Parties this week, countries from around the world came together in Glasgow to debate solutions to the challenges posed by climate change. The message ahead of COP26 was clear: we need to act now if we are to stand a chance of meeting the goals established by the 2015 Paris Agreement, limiting global warming to 1.5°C. This is going to require a radical transformation of the existing energy system over the next 30 years. But while challenging, the need for change presents opportunities for innovative zero-carbon technologies. In May this year, COP26 President-Designate Alok Sharma visited the new Eden Geothermal site in Cornwall, UK, marking the start of drilling at this pioneering project, and signalling a message of support for geothermal energy and its role in the future energy mix.

Patent filing statistics provide useful insight into tomorrow’s technology landscape. A joint report by the European Patent Office (EPO) and the International Energy Agency (IEA) shows a trend of growth in patents for clean energy technologies since the turn of the century, as innovators stake claims on the future clean energy space. While this growth is encouraging, the figures also reveal an urgent need for further innovation. Overall, the growth seen from 2016 onwards falls well short of the rapid rise seen in the period to 2013, which is surprising in light of the urgency of the climate crisis. With the need for innovative solutions to meet climate change targets, and declining growth in clean energy innovation, comes an opportunity for disruption; for new or underutilised technologies to move to a prominent position on the energy stage.

Geothermal energy

Geothermal energy has long been used as a direct source of heat and for generating electricity, with a global installed electricity capacity of 15,608MW in 2020. To date, however, geothermal sources provide only a fraction of the world’s energy needs. With increased reliance on variable supplies like wind and solar, policy disincentives for fossil fuels, and developments in energy storage and distribution, the time could now be right for its wider scale adoption, and many experts see geothermal energy as an essential component in the future energy mix.

Geothermal energy utilises the Earth’s internal heat – heat generated during the formation of the planet and sustained by radioactive decay. Since it can be used without being depleted it fits the definition of renewable energy. The flow of heat to the Earth’s surface is estimated at between 43 and 49TW, which more than doubles humanity’s current energy consumption, but geothermal energy extraction has, to a large extent, been constrained to regions with active volcanoes or where plate boundaries merge. Here, the Earth’s internal heat is accessible at or close to the surface. One of the most active geothermal areas is called the Ring of Fire, which encircles the Pacific Ocean and is home to New Zealand, Indonesia, the Philippines, Japan, the west coast of the US and Mexico. All of these regions are represented in Think GeoEnergy’s Top 10 Geothermal countries for 2020. A list which also includes Turkey, Italy, Kenya and Iceland, all countries known for their volcanic activity.

However, as evidenced by the Eden Geothermal project in the UK, the geographical reach of geothermal energy utilisation has been broadened by developments in deep-drilling techniques, which allow access to high temperatures in the Earth’s mantle two to three miles down. At these sorts of depths, hot water or rock can be accessed across much of the planet, meaning that utilisation of geothermal energy is not so geographically constrained. Indeed, research has shown that geothermal energy could provide 20% of the UK’s electricity demand, in addition to heating.

Research has shown that when geothermal energy is developed, it will be capable of providing around 20 per cent of the UK’s current electricity demand plus a vast amount of heating.

Patent trends in geothermal energy*

Evidence of innovation relating to deep-drilling is supported by patent data, where geothermal energy filings for drilling techniques come second only to heat pumps, with over 8,000 patents in the last 10 years.

There is also substantial patent activity relating to three types of geothermal power station. Each operates in a different way, but implements the same basic design of drawing hot water and steam from the ground to spin turbines and generate electricity. Traditional dry steam geothermal power stations show the most patent activity, with over 5,000 patents filed in the last 10 years, while there are nearly 4,000 filings for more complex (and more common) flash steam power stations. Both rely on high temperatures: 150°C or higher for dry steam and 180°C or higher for flash. By contrast, more recent binary cycle power stations are able to utilise fluid temperatures as low as 57°C. To date, filings in this area are lower, at nearly 2,000. However, lower temperatures bring greater flexibility and this, coupled with advances in deep-drilling, has the potential to see geothermal energy utilisation more widely deployed in the future.

Another key area of development for geothermal energy is remote sensing, where nearly 4,500 patents were filed in the last 10 years. These are sophisticated devices and techniques, many using AI to advance geothermal exploration. Technical advances have the potential to drive down the cost of exploration and reduce risk to investors.

Heat pumps account for over half of patent filings officially tagged as geothermal energy in the last 10 years. While many of these filings relate to ground source heat pumps which utilise solar energy absorbed at the Earth’s surface rather than geothermal energy in a strict sense, the high patent activity is an indicator of innovation in an area that has potential to reduce reliance on fossil fuels and drive down emissions.

Geographical distribution of patent activity

Geographical distribution of patent activity gives insight into the location of technology centres with specialisms in different aspects of clean energy innovation. According to the EPO/IEA report, centres in Europe, Japan and the US dominate, accounting for more than three quarters of patent filings since the turn of the century. South Korea and China are some way behind, but show a sustained increase in recent years.

Japanese, US and South Korean companies all appear in the top 10 applicants for geothermal patents in the period from 2010-2020, with Toshiba heading the list, followed by Haliburton and GE. However, the top 10 companies account for only 6.5% of total filings, indicating a wide spread of applicants in this open and emerging field. And if we look at where these applicants are filing patents, China dominates, followed by the US, Japan, South Korea, Australia, Canada and Germany.

Notably, the geographical distribution of patent activity in geothermal energy does not correlate directly with production. While the US and Japan are both listed in the top 10 producers of geothermal electricity, China is not. The use of geothermal resources in China has a long history, but large-scale exploration and development only began more recently. For decades, low-temperature geothermal resources in China were directly utilised, but geothermal energy generation is still in its infancy, which may explain China’s absence from the top 10 geothermal energy producers, despite a high level of R&D activity in the field.

Indonesia and the Philippines also present interesting anomalies. They occupy the number 2 and 3 spots in the top 10 geothermal energy producers. Indeed, with measures in place to reduce reliance on coal, Indonesia looks set to move to the number 1 spot. However, we see very few patent filings in these countries, suggesting that applicants may be neglecting key territories. The finding reflects a challenging patent environment and barriers to licencing and commercialisation of IP assets in both countries. The US Chamber’s International IP Index, which scores countries on the strength of their IP systems, ranks Indonesia 48th out of 53 countries, with a score of 30.16%, and the Philippines 38th, with a score of 39.81%. However, this could change over the 20 year lifetime of a patent and applicants for geothermal energy technologies would do well to give thought to filing patents in countries where geothermal energy plays a key role in the economy.

Patent activity by research organisations

Another interesting statistic to come out of the EPO/IEA report is that patent filings in the geothermal energy field originating from public research organisations and universities has increased from 2% in the period from 2000-2009, to 11% in the period from 2010-2019. Although this is not high compared to areas such as carbon capture and bioenergy, an increase in interest by research organisations often precedes increased activity on an industrial scale and should be regarded as a positive sign for geothermal energy.

Summary

At present, geothermal energy is a small but important player on the global energy stage. In those countries where geothermal resources are easily accessible, geothermal solutions present a clean, reliable and consistent source of heat and electricity. And improvements to geothermal exploration, deep-drilling and utilisation of lower temperatures have the potential to make geothermal energy accessible more widely.

Most net-zero scenarios rely heavily on wind and solar. The variable nature of these renewable energy sources, which are dependent on seasons and the weather, means that they require support from other technologies which aren’t quite there yet. Advanced batteries, hydrogen, smart grids and so on could all fill this gap in time. However, innovators, investors and policy makers would do well to look at the potential for geothermal energy, with its ability to operate consistently at a high availability rate, to provide support for other renewables.

*Patent searches performed using the Y02 patent classification code, which tags technologies for mitigation or adaptation against climate change.

This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.