Expert Interview : the potential of geothermal energy in the United Kingdom

The potential for geothermal energy in the UK is huge, yet it remains significantly underutilised. Which is odd when you consider we've had thermal spas for centuries. The Romans took advantage of our hot springs and we can too.

However, in terms of market readiness, there is still a long journey ahead. The challenges range from increasing our understanding and technical capacity to evaluating and designing systems, to enhancing our ability to build and construct. This involves everything from drilling rigs and heat pump manufacturers to installers, alongside optimizing operations through digitalisation. While we may be at an inflection point, significant growth is required to reach full market readiness.

When it comes to public awareness, most people immediately think of solar and wind energy, which are fantastic for decarbonising electricity. However, a critical issue that often goes unnoticed is the decarbonization of heat. The UK remains heavily dependent on gas, which accounts for a substantial portion of our emissions, and this will be a major area to address as we move forward.

The main hurdle for geothermal energy adoption in the UK is the cost difference between electricity and gas on a per-kilowatt-hour basis, which slows down progress. While there is considerable discussion on this issue, it is difficult for the government to move quickly due to the country’s significant reliance on gas. 

Additionally, there are fewer economic incentives and grants available for geothermal energy in the UK compared to other countries, which makes widespread adoption even more challenging. 

To make geothermal viable in today’s economic climate, two key strategies stand out. First, systems need to be designed and “right-sized” to avoid overbuilding. This involves thoroughly understanding the subsurface, using inclined wells to increase thermal storage capacity, and maximizing heat recovery or incorporating geocooling to reduce the size of the borehole array needed. Second, digital tools should be employed to optimize performance, reduce energy consumption and costs, and ensure the ground array remains efficient in the long term. This performance guarantee could then unlock the long-term investment needed for this underutilized and not well-understood energy source.  

Geothermal energy is a local, sustainable, and resilient resource. It has the potential to reduce energy consumption by harnessing energy from the ground, which in turn alleviates pressure on the electricity grid. Furthermore, geothermal is both flexible and scalable, making it suitable for individual buildings as well as for large heating networks that can connect hundreds or even thousands of properties. 

At Celsius Energy, we are addressing various barriers to help geothermal energy scale up. First, we focus on optimizing system design to enhance efficiency. Additionally, we have developed installations that require significantly less surface area—our systems occupy the equivalent of two parking spaces, compared to the hundreds typically required for conventional installations. Lastly, we leverage digital tools to maximize performance and efficiency. Our goal is to reduce the initial capital investment and, in turn, reduce energy consumption, leading to lower bills, less exposure to price fluctuations, and full decarbonization.