We only need heat

The conventional geothermal industry needs heat, flow and permeability (a way for fluid to move naturally through porous or fractured rock). That combination shows up reliably above 250°C, in volcanic settings. Below that, in the 140–180°C range we see across the Gulf of Thailand, the resource exists, but the natural flow and permeability you'd need to extract it economically often doesn’t. That's why this heat has been written off. It isn't that the temperature is too low to be useful, 150°C is genuinely good enough to generate electricity, or to convert into cooling systems or heating directly. It's that nobody had a way to get at it without relying on rock that wasn't cooperating.

GeoAgni believes these medium-temperature resources can become commercially viable through advanced closed-loop well architecture, enhanced heat-transfer fluids, and efficient power and industrial-heat systems.

Unlike conventional geothermal projects which require naturally occurring fluids, sufficient underground flow and permeable rock, GeoAgni circulates an engineered working fluid through a sealed closed-loop system. Its technology, therefore, doesn’t depend on natural fluid flow or reservoir permeability.

We drill two wells and connect them underground into a single loop, using a magnetic ranging technique borrowed directly from the oil and gas industry; a tool that lets you detect the casing of the first well from the second and steer precisely into an intersection, sometimes two or three kilometres down. It's a niche technique in oil and gas, used only in special cases. For this, it's central. Once the loop is closed we don't need the rock to cooperate at all. We only need heat, which is there anyway.

We didn't stop at the well design. Water is the default fluid for heat transfer but it isn't the best one. Our in-house R&D team (people with a materials and nanotechnology background) developed a nanofluid that improved heat-transfer performance by up to 300% over water in lab testing. That single piece of engineering means a better heat transfer, which then means shallower wells can produce the same output, and shallower wells are cheaper. Cost per megawatt is, and always will be, mostly a drilling cost question. Improve the fluid, and you improve the economics of the entire project.

This approach could expand geothermal development beyond volcanic zones and provide firm, clean, 24/7 energy close to industrial facilities, data centres, and other major energy users. That last point matters more than people realise. Solar is intermittent, you need batteries and a lot of land to make it firm, and even a 100-megawatt solar farm needs a large footprint. Geothermal, once the well is drilled, is a continuous heat source sitting there whether you use it or not. It doesn't care what time it is.

24/7 energy 

We're pursuing data centres as our first serious customer segment, for reasons that are almost entirely about demand shape and scale. A data centre runs 24/7, needs both clean electricity and cooling. Critically, it wants to own the carbon credit itself rather than buy it secondhand. Thailand and Southeast Asia more broadly are in the middle of a large-scale data centre build-out; the region is expecting data centre demand to grow toward roughly 30 gigawatts over the next 15–20 years. Economically, a project only makes sense above about five megawatts of demand and a few acres of land. Below that the drilling cost doesn't amortise. That threshold naturally points you toward large industrial users and data centres rather than smaller commercial customers.

Selling something you can't see is its own challenge. Nobody can inspect a reservoir two kilometres underground before they commit capital to it. What gets a customer over that line, in my experience, is proof from an adjacent domain they already trust. In our case, drilling data. Because I have my own drilling company with years of well data across the region, I can show a prospective customer actual measured heat data beneath their site, not a model. That, plus being able to explain the engineering credibly because I've spent two decades in the ground myself, is what turns scepticism into a signed contract.

We work with customers under two structures: a straightforward EPC-style build where the customer owns the well and plant outright and pays us a lump sum for the service, or a long-term power purchase agreement (typically 20 years) where GeoAgni owns and operates the asset and the customer simply buys electricity, cooling or heat. We started with the first model because it gets revenue in the door immediately without requiring us to raise the full capital ourselves. But the PPA model is the one we're building toward. Owning the generating assets, and stacking them ten megawatts here, fifty there, eventually a real portfolio, is how you turn a drilling and engineering business into an energy company.

You need real money

I won't pretend the capital intensity is a minor detail. You cannot sell "a small piece" of a geothermal well the way you can sell a piece of software. You need real money before you have any revenue at all, and that is the defining challenge of climate tech as a category. Our answer has been to run two businesses in parallel: exploration and drilling services generate income now, while we raise capital for the asset-owning business we want to become. It can be slow but it's how you survive long enough to get there.

Building the team required the same kind of pragmatism. I know who's good in this industry because I've spent two decades in oil and gas conferences and drilling operations across the region. That network is the most useful asset I brought into this company, arguably more useful than any one piece of intellectual property. Full-time specialist expertise in this field is expensive, so we lean heavily on consultants and subcontractors, brought in project by project, alongside a core in-house team of around 30, roughly 20 of whom are engineers. What I couldn't bring myself (thermodynamics, surface facility design, steam turbines, the material science of the fluid and piping) I had to learn, and I'm still learning it one conference and one new collaborator at a time.

We're already competitive on price against solar-plus-battery, wind and gas in our target segment, and the economics only improve with scale. The more wells we drill, the cheaper drilling gets and drilling is most of the cost. We're currently working across Thailand, Taiwan, Vietnam and have explored Singapore, and expect to have around 30 megawatts of installed capacity within three years, with Thailand's national power development plan targeting roughly 300 megawatts of geothermal capacity over the next 20 years. We'd like to be a meaningful part of that.

Patience and humility are crucial to building in climate technology

If you want to build in climate tech, you have to actually love it, because the timeline will test whether you do. This isn't software, where you can build alone at a desk and ship. You're building physical infrastructure, raising capital against a technology that's still proving itself, and none of that happens quickly. You need patience and a genuine tolerance for being new at things. I've spent 20 years as an expert in drilling and I'm now deliberately a beginner again in thermodynamics and materials science. It’s a big trade, but if that appeals to you, the resource is enormous and mostly untouched.

GeoAgni is unlocking a previously underutilised geothermal resource class across a vast and underserved geography and we're just getting started.

Mongkhol Jandakaew, Founder and CEO of GeoAgni, participates in the Future Industries Partnership, a three-year philanthropic programme supported by HSBC and delivered by Third Derivative and Founders Factory. The mission is to help accelerate the deployment of innovative climate technologies needed to decarbonise heavy industries such as steel, cement, and chemicals across Asia and the Middle East..