The rapid development of industry has brought progress in productivity to mankind, but it has also brought energy anxiety. In today’s deteriorating global environment and the escalating energy crisis in various countries, more and more people have begun to think: Where is the road to energy for mankind in the future?
The answer is: the road is under our feet. In the depths of our planet, there is a kind of energy that has never been exploited on a large scale – geothermal energy. If fully released, this energy is enough for all mankind to use for 2.3 billion years! Today, an American company called Quaise Energy is trying to drill 20,000 metres deep into the underground treasure with cutting-edge millimetre wave drilling technology.
What is geothermal energy?
Geothermal energy is contained within the Earth, and there are two main sources of this energy: the residual initial heat from the formation of the Earth, and the nuclear energy produced by the continued decay of radioactive elements such as uranium and thorium in the Earth’s core. It is these heat flows within the Earth that drive volcanic eruptions, the emergence of hot springs, and geological activity such as earthquakes.
Depending on the temperature, scientists classify geothermal energy into three different types: high temperature (above 150°C), medium temperature (90-150°C) and low temperature (below 90°C).
High-temperature geothermal energy is mainly used for power generation. For example, the ‘Geysers’ geothermal field in northern California, USA, is the world’s largest geothermal power generation complex, with 22 power stations with a total installed capacity of up to 2,080 megawatts, which is enough to supply power to millions of households. Medium- and low-temperature geothermal energy is used for heating buildings, industrial processes, greenhouse farming and spa treatments.
The potential for geothermal energy is beyond our imagination. The U.S. Department of Energy estimates that just 1% of the Earth’s shallow heat is enough to support human use for 2 million years. And if we can dig deeper into the earth’s heat, this energy can even be used by all human beings for 2.3 billion years.
The advantages of geothermal energy are also very obvious. Firstly, it is green and environmentally friendly, and the geothermal power generation process has almost no carbon emissions. At the same time, this energy source is very stable, it is not as dependent on weather changes as solar or wind energy, as long as the development is done properly, geothermal resources can be supplied uninterruptedly throughout the year.
However, the challenges of geothermal development should not be underestimated. High initial investment, complex exploration processes and long development cycles are major obstacles. In addition, the high temperature and high pressure environments place even more stringent demands on drilling equipment. This explains why, despite its obvious advantages, geothermal energy still accounts for a relatively low share of the global electricity mix.
Status of geothermal development in various countries
At present, many countries around the world are actively exploring the development and application of geothermal resources. Especially in some countries with rich geothermal resources, such as Iceland, Indonesia and Kenya, geothermal has become an important pillar of energy transformation. For example, Iceland’s geothermal system heating coverage has reached 90 per cent, freeing the small Nordic country from its dependence on fossil fuels.
The Government of Indonesia is also making an ambitious push into renewable energy, with plans to significantly increase its geothermal power capacity from the current 2,356 megawatts to 4,000 megawatts over the next 10 years.
Meanwhile, Kenya has made geothermal one of the country’s future energy pillars, and geothermal power now accounts for 48 per cent of its national electricity. Their goal is to expand geothermal power capacity to 10,000 megawatts (MW) by 2037, which is ten times the current level.
In Europe, several countries are also actively trying to incorporate geothermal energy into their energy transition programmes. For example, the United Kingdom is exploring the use of underground heat from abandoned coal mines to develop geothermal projects in the hope of transforming these old mines into new energy bases.
Not to be outdone by France, in 2023, Australian energy company Vulcan entered into a co-operation agreement with European car manufacturer Stellantis, with plans to utilise geothermal heat to provide energy support for an industrial site in Mulhouse in eastern France. According to estimates from the French Geological and Mineral Research Agency, geothermal energy is expected to meet around 70 per cent of the country’s heating needs in the future, although this is currently just one per cent.
In addition, emerging technologies are driving the development of geothermal energy. For example, Enhanced Geothermal Systems (EGS), which has been at the forefront of the international geothermal energy community in recent years, is transforming the challenges of dry hot rock development. Through techniques such as hydraulic fracturing, EGS allows rock formations without natural fluids to be utilised.
Internet of Things (IoT) and Artificial Intelligence (AI) technologies, which have developed rapidly in recent years, are being used in geothermal projects in the East African Rift Valley to monitor data in real time and optimise the production and use of energy.
Going 20,000 metres underground
Now, the American company Quaise Energy is starting a technological revolution in geothermal development. They are working on an unprecedented millimetre wave drilling technology in an attempt to exploit geothermal energy 20,000 metres deep underground.
Conventional drill bits tend to wear out in high-temperature, high-pressure formations and need to be replaced frequently, which is not only time-consuming but also raises costs. Millimetre wave drilling technology, however, no longer has this limitation. It emits high-energy beams through the cyclotron, which directly penetrates hard rock formations and can vaporise the rock instantly, avoiding the problem of drill bit wear and greatly improving the stability and efficiency of drilling.
Millimetre-wave drilling is capable of penetrating 20 metres of rock per hour, and a 20,000-metre-deep well could theoretically be completed in just 42 days, several times faster than conventional drilling. With this technology, geothermal energy development will also not be limited to the Pacific Rim Volcanic Belt and other geologically active areas, but can be applied on a global scale.
Currently, Quaise Energy has planned a clear roadmap for commercialisation. They plan to complete prototype testing of the millimetre wave drilling technology this year to demonstrate its application in real-world environments, and by 2026 they hope to be commercially viable, officially bringing this revolutionary technology to market.
In addition, this drilling technology is able to interoperate with EGS technology. Millimetre wave drilling can reach deeper into the ground, creating a hotter thermal reservoir for EGS. Through the circulation channels created by the EGS system, the injected water is able to absorb the heat from the hot underground rock, turn it into steam and transfer it to the surface, providing a stable power source for electricity generation.
With this technological innovation, Quaise Energy plans to reduce the cost of geothermal power generation to $20-$40/MWh in the future, a level of cost that is competitive with wind and solar, providing a more attractive option for the global energy market.
Conclusion
At this critical moment of energy transition, mankind is standing at the crossroads of history. Various new energy sources like solar energy, wind energy and hydrogen energy have been spreading out, but they have their own shortcomings: they either depend on the sky to eat, or the cost is high, while the emergence of geothermal energy has shown us another possibility.
The development and utilisation of geothermal energy by mankind is not only an energy revolution, but also a revolution of confidence. Because once mankind has truly unleashed the potential of geothermal energy, then no matter how times change in the future, as long as the earth is still under our feet, we will not lack of light and warmth.