From Gas Engines to Data Centers: How Distributed Energy Found Its Moment
Reflections on 2008-2024
Clarke Energy in 2008 was not what it would become. It was a Liverpool-based business with deep technical roots in gas engine technology, built around the Jenbacher engine range and a clear focus on delivering distributed power solutions to industrial and commercial customers. The company had been operating since the 1980s, had genuine engineering depth, and was beginning to think carefully about how its core capability, deploying and maintaining reliable onsite generation, could extend into adjacent markets. One of those adjacencies was biogas and anaerobic digestion, which is where I came in.
My initial role was to support the marketing and commercial development of the Haase MBT-AD system, a German mechanical biological treatment and anaerobic digestion technology Clarke Energy was looking to establish in the UK market. It felt, at the time, like a continuation of the work I had been doing; the same fundamental question of how to take a technically credible system and build the commercial and regulatory conditions for it to succeed. The waste sector was familiar territory. The technology was different but the challenge was recognisable.
What I did not fully anticipate was how quickly the work would broaden.
The engine at the centre of everything
The Jenbacher gas engine is a remarkable piece of equipment. It is designed to run on a wide range of gaseous fuels, natural gas, biogas, landfill gas, sewage gas, coal mine methane, hydrogen blends, with high efficiency and very high availability. That fuel flexibility is not incidental. It is the engineering principle that connects almost everything Clarke Energy does across its markets. An engine that can run on landfill gas today can run on biogas tomorrow and on a renewable gas blend the year after. The asset does not change. The fuel pathway does.
That insight took time to fully appreciate, but once understood it reframes what distributed energy is actually about. It is not about any single fuel or any single technology. It is about placing reliable, controllable, fuel-flexible generation capacity at the point of need and designing systems that can evolve as the energy landscape around them changes. This is the principle that would eventually connect waste-to-energy, biogas, CHP, microgrids, and data center power into a single coherent body of work, even though at the time those connections were not yet obvious.
Scaling internationally
By 2011, my role had expanded to cover Clarke Energy's international marketing, then across ten countries. That breadth introduced a set of observations that would prove increasingly relevant over the following decade. In markets where grid infrastructure was constrained, unreliable, or simply absent, distributed generation was not a supplement to central power; it was the infrastructure. Extractive operations in remote Australia, industrial facilities in sub-Saharan Africa, agricultural processing plants in developing economies: these were environments where the questions about reliability, fuel supply, maintenance logistics, and operational continuity were not theoretical. They were immediate and the consequences of getting them wrong were serious.
Those environments produced a practical education in what resilience actually means as an engineering outcome. It means thinking about fuel storage and supply chain vulnerability. It means designing for maintainability under difficult conditions rather than optimal conditions. It means understanding how a system behaves when something unexpected happens, not just when everything works as planned. And it means designing with the full operational life of the asset in mind rather than just its commissioning performance.
This thinking would take years to become fully articulate, but it was forming in those early international projects in ways I did not entirely recognize at the time.
A conversation that had already started
By 2016, something was shifting in the data center sector that those of us in distributed energy had been watching for some time. Facilities were growing. Power densities were increasing. The questions being asked at conferences were beginning to include onsite generation, CHP efficiency, and the long-term adequacy of grid supply for large-scale digital infrastructure. I spoke at DataCentres North that year on exactly this topic not as a prediction but as an observation of a trend that already seemed underway.
The conversation was early. Most of the industry was still focused on standby diesel resilience, renewable energy procurement, and PUE optimization. But the underlying infrastructure question; how do you supply reliable, large-scale power to facilities whose operational requirements are continuous and unforgiving, was one that distributed energy had been answering in other sectors for decades.
In 2017, I was part of the UK government pavilion at the United Nations COP23 in Bonn, speaking on hybrid power generation, microgrids, and grid-balancing technology. The framing there was around energy transition and smart systems flexibility rather than data centers specifically, but the engineering principles were identical. Distributed, controllable, fuel-flexible generation. Systems designed to interact with wider networks rather than operate in isolation. Infrastructure that could evolve rather than be replaced.
The acceleration
The period from 2019 onward changed the pace of everything. Clarke Energy's acquisition by Kohler, and subsequently the formation of Rehlko as a standalone energy business, brought new resources and a sharper strategic focus. The decision to relocate to the United States in early 2022 reflected where the market was moving fastest: a country with extraordinary data center growth, significant grid constraints in key markets, and an increasingly urgent conversation about how AI infrastructure was going to be powered.
The AI data center conversation that became industry-defining in 2023 and 2024 was not, from where I was standing, a sudden development. It was the arrival of a question that the distributed energy sector had been positioned to answer for years, about what happens when grid timelines extend beyond investment horizons, when power density exceeds what traditional infrastructure was designed for, and when the cost of downtime becomes large enough that reliability is no longer a specification but a strategic priority.
The election as Vice President of the COGEN World Coalition in 2024 was, in one sense, a recognition of that moment — the point at which CHP and distributed generation moved from a background conversation in the data center sector to a central one. But from another perspective it simply reflected a body of work that had been building since the early Clarke Energy years, through the international projects, the Africa engagements, the microgrid conferences, and the gradual accumulation of evidence about how distributed energy systems actually behave under real operating conditions.
What the arc looks like in retrospect
I have been asked, more than once, whether the move toward data center power represents a pivot, a decision to reposition around a fashionable topic at the right moment. The honest answer is that it does not feel that way from the inside. The questions I am working on now; how do you deploy reliable power quickly in a constrained environment, how do you design systems that can evolve as fuel pathways, carbon constraints, and grid conditions change, how do you balance speed and long-term performance in infrastructure decisions that will last twenty years, are recognizably the same questions I was working on in different contexts from the beginning.
The waste sector taught me that technology readiness and market readiness are not the same thing. The international projects taught me that resilience is a systems outcome rather than a component specification. The biogas and CHP years taught me that fuel flexibility is an asset that compounds over time. The microgrid work taught me that the control layer is where the real complexity lives. And the current data center moment is teaching me that when all of those lessons converge on a single sector at a single point in time, the opportunity to contribute something genuinely useful is significant.
That is what the last two decades of distributed energy work has been building toward. Not a pivot. A preparation.