In our previous blog posts about renewable energy, our team has covered wind, solar, carbon capture, and nuclear fusion. To continue this series, I’d like to add geothermal energy to the discussion.

Geothermal energy is experiencing a bit of a renaissance. Once undervalued as a viable way of generating energy at commercial levels, geothermal is now seeing revived industry interest thanks to recent breakthroughs in enhanced geothermal systems technology. The U.S. Department of Energy is now projecting that geothermal energy could account for 8.5% of the country’s electricity generation by 2050. (Currently, it accounts for just 0.4%.)

If you’re investing in geothermal, you’re likely also considering what the right business strategy might be for protecting your intellectual property — including seeking patent protection. To determine this, it’s important to first understand what geothermal is, what is patentable within the field, and what the current patent landscape looks like.

What is geothermal energy?

Geothermal energy comes from heat that is generated deep within the earth. Heat from the earth’s core comes from two sources: 1) the friction and gravity resulting from the planet’s formation; and 2) the ongoing decay of radioactive isotopes.

Geothermal energy offers four key advantages over conventional energy sources:

  1. Renewable: Heat from the earth’s core is constantly replenished by naturally occurring processes, and will not deplete in the foreseeable future.
  2. Baseload: Geothermal energy is produced at a consistent rate 24/7, regardless of time of day or weather conditions, making it ideal for balancing out intermittent power sources like wind or solar.
  3. Clean: Geothermal energy has a significantly smaller carbon footprint than burning fossil fuels or natural gas.
  4. Local: Some form of geothermal energy can be accessed and utilized from any location in the world.

Geothermal energy: Patentable technology areas

As geothermal technologies typically take the form of tangible systems and methods, they are usually subject-matter eligible for patent protection.

These technologies also involve multiple inventions working together, and it may be possible for you to seek patent protection for these individual products and processes. Below, I’ll briefly cover six common patentable technology areas for geothermal energy production, and offer examples of patents granted in each area.

1.    Downhole equipment

Downhole equipment refers to the tools used for:

  • Surveying the geology of a site to identify geothermal reservoirs
  • Facilitating drilling operations
  • Evaluating reservoirs
  • Completing well construction
  • Extracting fluids
  • Monitoring and maintaining the wellbore

Tools deemed novel, useful, and non-obvious may be eligible for patent protection. For example, Halliburton was recently granted a patent for their method of using temperature-based flow control to extract heat energy from a geothermal well.

2.    Downhole telemetry

Downhole telemetry refers to methods of transmitting real-time signals from drilling to the surface. An innovative way to use telemetry may be patent-eligible; for example, a group of Canadian inventors were recently granted a patent for their complete telemetry system involving a mud-activated power generator.

3.    Casing materials

Equipment for harnessing geothermal energy will be constantly exposed to fluids at high temperatures, making it important to use casing materials that are durable, stable, and leak-proof.

You may be able to seek patent protection if you have developed a new casing material, a new process for constructing casing material, or a novel construction of casing. For example, this granted patent describes a low alloy material as well as its method of manufacture.

In addition, techniques for casing cementing are also important here. Unlike oil and gas wells, the casing in geothermal wells is typically cemented the entire length of the well, because the casing materials will be subjected to geothermal temperatures for a much longer time than oil and gas wells. Such techniques could potentially be patentable; an example can be seen in this published patent assigned to Schlumberger.

4.    Working fluids

Producing geothermal energy requires the use of a fluid that converts thermal energy into mechanical energy through either a phase change or through compression and expansion. This is called a working fluid.

If you are able to create a working fluid with a novel composition, you may be able to protect it with a patent. For example, Halliburton holds a patent for their method of creating a grout fluid.

5.    Power cycles

Broadly, geothermal power plants can be divided into two main groups:

  • Steam cycles (for higher enthalpies)
    • Dry steam, which directly uses steam from underground reservoirs
    • Flash steam, which mixes hot, high-pressure fluid with cool, low-pressure fluid to create steam
  • Binary cycles (for lower enthalpies), which passes hot water through a secondary fluid with a lower boiling point in order to vaporize the secondary fluid into steam

You may be able to seek patent protection for a novel, non-obvious geothermal application. For example, ICE Thermal Harvesting LLC has a number of pending and granted patents relating to their system using an organic Rankine cycle.

6.    Environmental impact mitigation

While a relatively clean source of energy, geothermal still comes with some environmental disadvantages. Some examples:

  • Constructing geothermal plants can cause disruptions, from noise pollution to waste production
  • Geothermal plants may release small amounts of greenhouse gases
  • Geothermal plants have been linked to subsidence (land sinking), which could damage natural drainage systems and human infrastructure

You may be able to seek patent protection for an innovation that mitigates the environmental impact of geothermal technology. For example, Union Oil Company of California holds a patent relating to the process of controlling the emissions of certain pollutants from geothermal power plants.

Recent patent trends in geothermal energy technology

Above, we discussed several examples of patents filed in eligible technology areas for geothermal energy. Now let’s take a bird’s-eye view on general patenting trends in the industry.

Low, but increasing, industry interest in geothermal

We observed that there has been increased global interest in geothermal energy recently, thanks to investors paying more attention to enhanced geothermal systems (EGS) — a process for harnessing energy that involves injecting fluids into underground systems to open pre-existing fractures in the rock, thus creating permeability.

In line with this, the number of published patents relating to geothermal energy have increased in recent years. According to WIPO, just 43 patents were published from 2002-2006; but by 2015-2019, that number had increased 416%, to 179.

While this increase is encouraging, total industry interest in geothermal energy remains low compared to other forms of renewable energy. Even in 2019, patents relating to geothermal energy accounted for a mere 1.4% of all published patents in the renewables sector.

International patent filing trends for geothermal technologies

Since geothermal energy may potentially be harnessed from anywhere, it is also worth considering whether protecting your IP in multiple jurisdictions could confer long-term benefits.

According to WIPO, these 10 countries filed the most patent applications relating to geothermal technology from 2010-2019:

  1. United States (106 applications)
  2. Japan (40 applications)
  3. France (34 applications)
  4. Germany (28 applications)
  5. Republic of Korea (26 applications)
  6. China (23 applications)
  7. Italy (13 applications)
  8. United Kingdom (12 applications)
  9. Spain (8 applications)
  10. Denmark (4 applications)

It’s worth noting that the geographical distribution of patenting activity does not fully correlate with production trends for geothermal energy. For one, China is ranked sixth worldwide in terms of patent applications filed (as we see above), but does not even make the top 10 in terms of actual production. Conversely, Indonesia and the Philippines are number 2 and 3 in production — but few patents have been filed in these jurisdictions.

It seems that the value of patents for geothermal energy technology comes not only from their ability to protect IP, but also from their potential to be leveraged as business tools in specific regions.

Notable patent holders for geothermal technologies

There are two notable categories of patent holders for geothermal technologies: privately held energy companies, and the U.S. Department of Energy (DOE). Let’s take a deeper dive into the implications.

According to a 2021 report by the DOE, these are the top privately held companies worldwide listed as patent assignees for technology relating to geothermal energy:

  1. Chevron (USA)
  2. General Electric (USA)
  3. Ormat (USA)
  4. Dow (USA)
  5. Unisys (USA)
  6. Halliburton (USA)
  7. Rehau (Germany)
  8. Doosan (Republic of Korea)
  9. Schlumberger (France)
  10. Mitsubishi Heavy (Japan)

However, the list looks quite different if patents funded by the DOE are factored in — as, in that case, the DOE tops the list by a significant margin, making their contribution bigger than that of the ten largest companies. (A caveat: the DOE is not necessarily the assignee for every patent they have funded.)

This tells us that not only is the U.S. an undisputed industry leader in research and development for geothermal energy, but the U.S. government itself is driving much of the current industry interest in geothermal energy.

The future of renewables: Enhanced geothermal systems

The use of geothermal energy has not yet proliferated widely. In 2022, geothermal energy accounted for only 0.4% of all utility-scale generation in the United States. For all its advantages, geothermal energy still faces barriers to widespread adoption.

For naturally occurring geothermal systems, geology is a critical deciding factor. The process can take place only in hydrothermal areas — underground areas with enough heat, fluids, and permeability (the ability for water to freely move through underground rock).

However, many areas do not have enough fluids or permeability. That barrier, combined with the prohibitive costs of the drilling operations needed to evaluate geothermal resources, had negatively impacted industry interest in geothermal energy for years.

Now, EGS could potentially change all that. Simply, EGS artificially fosters the right conditions to harness geothermal energy, making it possible to build power plants in new and non-traditional geographies.

While it will take time for EGS to become commercially viable (the primary hurdle being the high cost of drilling activities), some prominent and promising EGS projects have recently sprung up, including:

Working with an experienced patent attorney to protect your IP

Geothermal energy is a relatively small but fast-growing field, meaning that it’s important to be proactive about protecting your IP in this industry in order to reap the full commercial benefits down the line. As such, it’s critical that you partner with a patent attorney who understands where the field is headed.

At Henry Patent Law Firm, we have strong experience with renewable energy, including geothermal — and we’re eager to help you craft a long-haul IP strategy tailored to your business’s needs. Contact us now to find out more.

Samuel Udovich

Sam Udovich is a patent attorney who helps tech companies develop patent portfolios, focusing on electrical and mechanical technologies.