Beyond the Hype: A Clear-Eyed Look at Geothermal’s Role in the Energy Transition – CleanTechnica

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When I began writing about geothermal energy, I did not expect it to turn into a project that would span a dozen in depth articles, weeks of research, lengthy discussions with experts and eventually a full report. The original intent was modest. I wanted to understand where geothermal actually fits in the broader energy transition, whether it was a sleeper solution being overlooked or a distraction dressed up in marketing gloss. I had a relatively informed position on its likely contribution to global energy, but had not spent significant time with the innovative approaches being explored that my change my position.

That exploration began in CleanTechnica, where I unpacked different aspects of geothermal in a public forum. Writing there and sharing summaries of the articles on LinkedIn meant that every piece was tested against a community of engineers, scientists, investors, policy makers and advocates who were quick to challenge weak claims and add missing context. Out of that open and iterative process came the report Beyond the Hype: Geothermal in Context, available as a pdf from the link, published by TFIE Strategy in September 2025. It is not a perfect product, but it reflects that process of being sharpened in public and adjusted along the way.

The report itself is wide-ranging. It opens with a foreword that admits the challenge of writing honestly about geothermal. It is an industry where geology, engineering, and economics intersect in messy ways, and where enthusiasm can run well ahead of evidence. From there the report walks through the core technologies, beginning with conventional geothermal generation. In the right geographies this remains an excellent source of low-carbon power, running at capacity factors that fossil plants envy. Yet the geography is limited, and in most parts of the world geothermal electricity will never be more than a rounding error.

A consistent lens throughout the report is Bent Flyvbjerg’s work on megaproject risks, which provides a way to cut through optimism and look squarely at where failure is most likely. Flyvbjerg’s iron law — that projects are over budget, over time, over and over again — shows up repeatedly when drilling is deep, timelines are long, and technologies are first-of-a-kind. By applying that framework, the report distinguishes between geothermal approaches that resemble modular, repeatable builds, such as district heating loops and industrial heat pumps, and those that carry the stacked risks of nuclear-scale ventures, such as enhanced and ultra-deep drilling. This perspective does not dismiss ambition, but it grounds the conversation, making clear where capital is most likely to be stranded and where geothermal can quietly deliver value today.

Closed-loop geothermal gets a detailed chapter, with Eavor and its peers given credit for their ingenuity but also examined through the lens of costs, efficiency limits, and the risks of first-of-a-kind drilling systems. Enhanced geothermal, so often framed as just around the corner, is weighed against decades of false starts, seismic events in Basel and Pohang, and financial models that rarely add up. Ultra-deep drilling, whether by plasma, microwaves, or lasers, is acknowledged as fascinating engineering but placed firmly in the category of long-tailed risk rather than near-term solution.

The middle of the report shifts focus to applications that already work. China’s district heating buildout, now measured in tens of gigawatts of capacity, shows how shallow and medium-depth geothermal can scale in ways that matter. Sinopec’s decision to pivot from gas distribution to heat networks is treated as a practical example of how utilities can escape the death spiral of stranded gas pipes, something Western utilities still resist. Seasonal thermal storage, once dismissed, is shown to work in Denmark and Alberta, with boreholes and water pits serving as seasonal batteries for heat. Industrial heat pumps combined with moderate-depth aquifers emerge as one of the most compelling tools in the near term, with real-world examples in Germany and New Zealand already cutting fossil heat demand. Even geothermal cooling for data centers, while niche, is documented as a practical way to reduce electricity demand in a sector that is growing rapidly.

The final sections of the report deal with framing and messaging. Too much of the geothermal sector has borrowed the language of gas and nuclear, leaning on baseload narratives and pointing to the supposed unreliability of wind and solar. This has led to positioning geothermal as a missing piece of the puzzle rather than as a complementary tool where it actually makes sense. The data, however, shows that wind and solar grids are already delivering world-class reliability in places like Germany and Denmark. Clinging to baseload rhetoric not only undermines renewables but also sets geothermal up for disappointment when its own projects run into delays, cost overruns, and black swan risks. The report argues that geothermal’s real strength lies not in competing with wind and solar on electricity, but in delivering flexible, distributed, and dependable heat.

A key addition added to the report are a full set of infographics developed to provide illustrations of key concepts and technologies the report deals with. While imperfect, they assist in communicating technical, operational and risk profiles of the approaches to geothermal.

So who should read this? Policymakers will find in it a guide to separating viable investment in shallow geothermal, district heating, and industrial heat from speculative drilling projects that promise more than they deliver. Utilities facing the inevitable decline of gas distribution should look closely at the Sinopec case study and ask themselves whether blending hydrogen is really a strategy or just a stall. Investors should take the time to absorb the sections on megaproject risks and cost trajectories, especially those tempted by ultra-deep or enhanced geothermal pitches. Industrial leaders who are serious about decarbonizing their heat demand will find practical pathways that use existing technologies, not science projects. And researchers or advocates can use it as a synthesis of global case studies and technoeconomic reasoning, a resource to point to in debates about what role geothermal should play.

I wrote this report in a spirit of humility, aware that I am not a geologist or a drilling engineer, but also aware that too often the energy transition is slowed down by grand claims that never materialize. My role has always been to weigh the evidence, to interrogate the economics, and to frame technologies within the broader system of decarbonization. If there are errors, they are mine, and I welcome correction. If there are insights, they come from the countless experts, critics, and readers who sharpened my understanding along the way.

The energy transition is not served by comforting illusions. It is served by clarity on what works and what does not. If you read the report and find it useful, I hope you will share it with colleagues, policymakers, and decision-makers in your networks. The work of decarbonization is urgent, and geothermal, in its proven forms, deserves attention not because of hype, but because in the right contexts, it simply works.