Follow the Carbon: A Simpler Way to Understand the Energy Transition

The energy transition has created an expanding vocabulary. Renewable energy. Green hydrogen. Blue hydrogen. Carbon capture. Net zero. Decarbonisation. Carbon removal. Synthetic fuels. Circular economy. Each term has a purpose. But sometimes the labels make the underlying engineering harder, rather than easier, to see. There may be a simpler question: Where did the carbon come from, where does it go, and what happens to it next? In other words: Follow the carbon. Carbon Is Not the Fundamental Problem Carbon is one of the fundamental elements of life and industry. It is present in fuels, chemicals, plastics, construction materials, agriculture and countless products essential to modern society. The problem is not simply that we use carbon. The fundamental problem is the continuing transfer of additional geological carbon from underground reserves into the active atmosphere, oceans and biosphere. Consider conventional natural gas. Carbon is extracted from a geological reservoir as methane: CH₄ It is combusted: CH₄ + 2O₂ → CO₂ + 2H₂O + energy The carbon atom has not disappeared. It has simply moved. Geological reservoir → natural gas → combustion → atmosphere Once we look at the system this way, the distinction between carbon and fossil carbon becomes extremely important. Capture Changes the Destination — Not Necessarily the System Carbon capture can intercept CO₂ before it reaches the atmosphere. That is important. But then we must continue following the carbon. If the CO₂ is captured and permanently stored underground: fuel → CO₂ → capture → geological storage we have changed its destination. If instead the captured CO₂ is combined with hydrogen and converted into another useful molecule: CO₂ + 4H₂ → CH₄ + 2H₂O the carbon becomes fuel again. The pathway becomes: CH₄ → energy → CO₂ → CH₄ Now something fundamentally different has happened. The carbon is no longer necessarily treated as waste. It has become a circulating process inventory. From Carbon Capture to Carbon Circulation This distinction deserves more attention. Traditional thinking often treats CO₂ as the final waste product of combustion: Extract → combust → capture → dispose A circular-carbon system asks whether another architecture is possible: Establish carbon inventory → use → capture → regenerate → reuse Carbon can therefore be considered in much the same way engineers consider other controlled inventories circulating through industrial processes. There will never be a perfectly closed physical system. There will be losses. There will be purge streams, maintenance losses, leakage and other practical limitations. The meaningful engineering question is therefore not whether carbon can circulate literally forever. It is: How many times can the same carbon inventory perform useful work before replacement carbon is required? That changes the metric. Instead of measuring only the gross amount of carbon passing through a plant, we should also measure the amount of new carbon entering the system. This Is Why Defossilisation Matters Decarbonisation and defossilisation are related, but they are not identical concepts. Some industries will continue to require carbon-containing molecules. The objective cannot therefore always be to eliminate carbon itself. A more fundamental objective is to progressively eliminate dependence on newly extracted fossil carbon. That is defossilisation. Imagine that an industrial system circulates 100 units of carbon and loses one unit during each cycle. The gross carbon throughput may remain approximately 100 units. But the requirement for new carbon is approximately one unit to replace the loss. The important number is therefore not merely the carbon circulating inside the system. It is the make-up carbon crossing the system boundary. As losses decline, dependence on virgin carbon declines. That is a very different way of measuring progress. Follow the Carbon — and Follow the Hydrogen Too Hydrogen provides another useful example. Hydrogen is frequently described according to how it is produced: green, blue, grey and other classifications. But again, labels alone do not describe the complete system. Ask instead: Where did the energy used to produce the hydrogen come from? How much electricity was required? What happens to the oxygen produced by electrolysis? How is the hydrogen compressed, stored and transported? What molecule ultimately uses the hydrogen? And what happens to that molecule afterwards? This becomes particularly interesting when electrolysis is integrated with other processes. Electrolysis produces hydrogen and oxygen: 2H₂O → 2H₂ + O₂ The oxygen is not an insignificant side stream. By mass, approximately eight kilograms of oxygen are produced for every kilogram of hydrogen. If an adjacent industrial process requires oxygen, that coproduct can potentially become part of the overall system architecture. The correct question is therefore not simply: “What is the cost of green hydrogen?” It is: “What is the performance and economics of the complete integrated system in which that hydrogen and its coproducts are used?” The Same Principle Applies to Power A power plant is normally compared using metrics such as efficiency, emissions intensity and cost per megawatt-hour. Those metrics remain essential. But system boundaries matter. A high-efficiency plant that continually requires newly extracted fossil carbon has a different long-term material flow from a system that captures and repeatedly circulates a controlled carbon inventory. Likewise, a lower-efficiency process that simultaneously performs CO₂ separation may be providing a function that another generation technology requires as an additional downstream process. Comparisons therefore need consistent system boundaries. Follow the energy — but also follow the carbon. And It Applies to Data Centres The same thinking is becoming increasingly relevant to AI infrastructure. A data centre cannot be understood simply by asking whether its electricity contract is renewable. We need to follow the entire physical system: Electricity → compute → heat → cooling → water → recovered heat and simultaneously: Primary energy → conversion → carbon flow → capture/recovery → reuse or release A truly sustainable data centre should ultimately be assessed as an integrated infrastructure system rather than merely an electricity consumer. Compute, power, cooling, heat and water increasingly belong within the same engineering boundary. Circularity Is Ultimately About Displacing Extraction Perfect circularity is physically unrealistic. Materials disperse. Equipment degrades. Molecules escape. Energy is dissipated. But that does not make circularity meaningless. It gives us a better definition of success. The objective is not necessarily to create a mathematically perfect closed loop. It is to maximise useful circulation while minimising the requirement for virgin resources. For carbon, that means reducing the amount of newly extracted geological carbon required to maintain useful economic activity. For metals, it means reducing new mining through recovery and reuse. For water, it means increasing recovery and reducing fresh-water demand. The principle is remarkably consistent: Keep valuable resources circulating for as long as practical, and minimise what must continually enter the system from nature. Perhaps We Need a Simpler Question The energy transition is extraordinarily complex. But sometimes physical accounting can cut through that complexity. When evaluating a technology, fuel or industrial process, ask: Where does the carbon originate? How much new geological carbon enters the system? Where does the carbon go after performing useful work? Can it be recovered? Can it be reused? How much is lost? How much virgin carbon must replace those losses? These questions do not depend on whether a technology has been labelled green, blue, renewable, low-carbon or carbon-neutral. They follow atoms rather than terminology. And that may ultimately be one of the clearest ways of understanding whether an industrial system is genuinely progressing toward defossilisation. Don’t just follow the label. Follow the carbon. Clean Energy and Water Technologies Pty Ltd (CEWT) Defossilisation through integrated energy and resource systems. #Defossilisation #FollowTheCarbon #CarbonCircularity #CarbonManagement #EnergyTransition #CarbonUtilisation #Hydrogen #CircularEconomy #DataCentres #SustainableEnergy