Hydrogen is increasingly described as one of the building blocks of the energy transition.

Hydrogen is increasingly described as one of the building blocks of the energy transition. Green hydrogen. Blue hydrogen. Renewable hydrogen. Low-carbon hydrogen. Clean hydrogen. These labels can be useful. But from an engineering perspective, perhaps there is an even simpler place to begin: Where did the hydrogen come from? And immediately after that: Where did the energy used to produce it come from? Hydrogen carries energy — it does not create it Hydrogen is an energy carrier and industrial feedstock, not a primary source of energy. To produce hydrogen, energy has to come from somewhere else. Water can be split through electrolysis using electricity. Natural gas can be converted through steam methane reforming. Coal can be gasified. Other chemical and biological pathways are possible. The hydrogen molecule may ultimately be identical. But the physical pathway producing it can be very different. That means evaluating hydrogen solely by the fuel at the point of use can hide much of the system that matters. We have to follow the energy upstream. Follow the energy Consider renewable hydrogen produced by electrolysis. The simplified pathway is: renewable resource → electricity → electrolyser → hydrogen → storage/transport → end use At each conversion and handling step, there can be energy requirements and losses. IRENA notes that electrolysis, and particularly subsequent reconversion of hydrogen into electricity or other energy forms, involves inherent conversion losses. This is one reason direct electrification can be preferable where it is technically and economically practical. That does not make hydrogen inefficient in every application. It means the appropriate question is not: “Is hydrogen good or bad?” It is: “What function are we asking hydrogen to perform?” Hydrogen may be particularly valuable where direct electrification is difficult — including some industrial processes, chemical production, long-duration energy storage and production of hydrogen-derived fuels. The system boundary determines the answer. Then follow the carbon Hydrogen itself contains no carbon. But hydrogen production can have a substantial carbon footprint. The IEA reports that global hydrogen production still remains dominated by unabated fossil fuels. Low-emissions hydrogen production reached almost 1 Mt in 2025, while total hydrogen demand surpassed 100 Mt. So saying simply: “This process uses hydrogen” does not tell us its carbon impact. We need to know how that hydrogen was produced. For fossil-derived hydrogen, follow the geological carbon entering the production system. For hydrogen produced with carbon capture, follow both the captured carbon and the residual emissions across the defined boundary. For electrolytic hydrogen, follow the electricity. Then follow the carbon associated with producing that electricity. The colour assigned to hydrogen is secondary to the physical flows underneath it. Hydrogen can move carbon as well as energy There is another dimension that receives less attention. Hydrogen can react with carbon-containing molecules to produce fuels and chemicals. For example: CO₂ + 4H₂ → CH₄ + 2H₂O Here hydrogen becomes part of a carbon-management pathway. The important questions then become: Where did the CO₂ originate? Where did the hydrogen originate? Where did the energy originate? What happens to the carbon in the methane after use? Does it enter the atmosphere? Is it captured? Is it stored? Is it reused? And does the overall system require another unit of geological carbon to replace it? Now we are no longer simply discussing hydrogen. We are examining a carbon-and-energy system. Why low-emissions hydrogen is struggling to scale The physical system also helps explain some of today’s commercial difficulties. The IEA reports that low-emissions hydrogen production grew by about 20% in 2025, but persistent barriers remain: high costs, uncertain demand, regulation and insufficient infrastructure. Only around 20% of newly signed low-emissions hydrogen offtake volumes in 2025 were backed by firm contractual commitments. This should not necessarily be interpreted as hydrogen failing. It may instead indicate that hydrogen needs to be deployed where its system value justifies the additional conversion steps and infrastructure. The objective should not be to maximise hydrogen production. The objective should be to use hydrogen intelligently where it helps transform the underlying energy and material system. Net zero, decarbonisation and defossilisation Hydrogen also demonstrates why these three concepts should not be treated as synonyms. Net zero describes a balance between greenhouse-gas emissions and removals across a defined boundary. Decarbonisation describes measures that reduce emissions or emissions intensity. Defossilisation asks a different upstream question: Can we progressively reduce the requirement for newly extracted geological carbon? Renewable hydrogen can contribute to decarbonisation and defossilisation when it replaces fossil-derived hydrogen or enables industrial pathways that require less new fossil carbon. But simply introducing hydrogen into a system does not automatically accomplish either. The complete material and energy flows have to be examined. Beyond the colour of hydrogen Perhaps the hydrogen debate has become too focused on colours. Green. Blue. Grey. Pink. Turquoise. Those classifications can help describe production pathways, but they should not replace physical analysis. Instead, ask: Where did the hydrogen come from? Where did the energy come from? Where did the carbon come from? Where did the carbon end up? And finally: Did this system reduce the amount of new geological carbon that had to enter the economy? Hydrogen may become extremely important in the energy transition. But its value will ultimately be determined not by its colour, nor by the molecule alone. It will be determined by the system in which we use it. Follow the energy. Follow the carbon. Because molecules do not carry labels. They carry atoms.

CEWT Carbon Recycling Technology (CRT/CCMS

Preliminary Technology Readiness Assessment Clean Energy and Water Technologies Pty Ltd (CEWT) Status: Preliminary internal assessment Purpose: Investor, government, EPC/EPCM, technology-partner and project-development discussions 1. Purpose of this Assessment This assessment establishes a structured and defensible Technology Readiness Level (TRL) position for CEWT’s Carbon Recycling Technology / Carbon Circular Management System (CRT/CCMS). A fundamental distinction is made between: 1. Component Technology Readiness — the maturity of the individual physical technologies incorporated into CRT/CCMS; and 2. Integrated System Readiness — the maturity of the specific CEWT process architecture that integrates those technologies into a managed carbon-recirculation system. This distinction is essential because CRT/CCMS does not depend primarily upon the invention of a new turbine, chemical reactor, compressor, heat exchanger, CO₂ separation process or methanation reaction. Its principal technological innovation lies in the integration and control of established and emerging industrial processes so that recovered carbon is maintained as a managed circulating inventory rather than continually replaced by newly extracted fossil carbon. Accordingly, the TRL of the overall CRT/CCMS system should not automatically be equated either with: • the highest TRL of its individual components; or • the lowest maturity associated with demonstrating the complete integrated architecture. Both levels of readiness must be reported separately. 2. Commercial Relevance of TRL The Carbon Gap / Carbon Management Europe paper identifies Technology Readiness Level as a measure of technological maturity extending from early research through demonstrated operation. For buyers and financiers, however, TRL has a broader commercial significance because it affects certainty of delivery. The paper considers five broad approaches: • TRL 4–6 — early-stage technologies; • TRL 6–7 — pre-commercial scale-up; • TRL 4–9 — segmented portfolios; • TRL 7+ — near-commercial projects; and • TRL 8–9 — commercially ready projects. The trade-off is therefore between technological diversity and delivery certainty. For CEWT, the implication is that the objective should not be to assign the highest possible TRL to CRT prematurely. The objective should be to demonstrate a credible pathway through successive levels of integrated-system validation until the overall system achieves commercially bankable readiness. 3. CRT/CCMS System Definition For purposes of this assessment, CRT/CCMS comprises the integration of the following principal functions: Energy conversion RSNG / methane-rich fuel is converted into electricity and recoverable thermal energy through a suitable prime mover. Carbon recovery CO₂ generated during energy conversion or associated process operations is separated and recovered rather than discharged as the intended normal carbon pathway. Hydrogen-rich synthesis-gas production Hydrogen-rich syngas and/or supplementary hydrogen is generated or supplied to provide the reducing hydrogen required for carbon conversion. Methanation Recovered CO₂ and/or CO reacts with hydrogen to regenerate methane-rich fuel. Water recovery Water generated through methanation and combustion/process reactions is separated and recovered where practicable. Carbon inventory management Carbon is managed as a circulating process inventory, with make-up carbon determined primarily by unavoidable system losses rather than by the gross amount of carbon circulating within the plant. Energy integration Electricity, process heat, steam, oxygen, hydrogen, water and other energy/material streams are integrated across the plant to reduce external energy and resource requirements. Process control and safety The complete system is operated using conventional industrial control, protection, isolation and safety systems appropriate to hydrogen, syngas, methane, oxygen and CO₂ service. 4. Component-Level Technology Readiness The following ratings are preliminary engineering classifications rather than independent third-party TRL certifications. CRT/CCMS subsystem Preliminary component maturity Assessment Gas turbine / gas engine power generation TRL 9 class Commercially established equipment operating globally on natural gas and related gaseous fuels. Heat recovery / steam generation TRL 9 class Mature commercial technology extensively deployed in combined-cycle and industrial applications. CO₂ compression to moderate process pressure TRL 9 class Industrial gas compression is mature; CRT duty and pressure must nevertheless be engineered for the selected capture/methanation system. Conventional CO₂ separation / solvent capture TRL 8–9 class at component level Commercially deployed separation principles and equipment exist. Performance within the specific CRT exhaust composition remains project-specific. Cryogenic CO₂ separation High component maturity, application dependent Established industrial separation principles; the particular exhaust-stream application requires vendor confirmation and performance validation. Steam methane reforming TRL 9 class Mature industrial hydrogen/syngas production technology. H₂-rich syngas production TRL 8–9 class depending on configuration Industrial syngas generation and conditioning are established; CEWT’s target composition and integration require project-specific engineering. Water electrolysis TRL 8–9 class at equipment level Commercial electrolysers exist; economics and dynamic integration remain project-specific. CO₂ methanation High component maturity Methanation chemistry and industrial reactor technology are established. Required operating conditions and guarantees must be confirmed by the selected licensor. Oxygen production — cryogenic ASU TRL 9 class Mature large-scale industrial technology. Oxygen production — PSA/VPSA TRL 9 class for applicable purity/range Mature technology subject to required flow and purity. Process heat integration TRL 9 engineering discipline Conventional process engineering practice; specific CRT integration remains to be demonstrated. Industrial PLC/DCS/SIS TRL 9 class Mature industrial control and safety technology. CO₂/H₂/CO/CH₄ analytical instrumentation TRL 9 class Mature industrial instrumentation technologies exist. Gas storage / fuel buffering TRL 9 class Established industrial storage technologies, subject to fuel composition and regulatory requirements. Water separation and recovery TRL 9 class Conventional industrial process technology. Important qualification These ratings describe the underlying technologies, not CEWT’s integrated CRT/CCMS system. They must therefore never be presented publicly as evidence that the overall CRT system itself has reached TRL 8 or TRL 9. 5. Integration-Specific Technology Elements The areas requiring CRT-specific validation are substantially different from the mature underlying hardware. They include: 5.1 Closed carbon-material balance The complete plant must demonstrate that recovered carbon can be repeatedly returned to the fuel-production pathway and that the circulating carbon inventory can be quantified. 5.2 Carbon inventory management The relationship between: • gross circulating carbon; • captured carbon; • temporary carbon inventory; • unavoidable process losses; • make-up carbon; and • product or purge carbon must be demonstrated dynamically as well as through steady-state mass balance. 5.3 Methanation integration The interaction among: • captured CO₂; • CO-containing synthesis gas; • hydrogen; • methanation reactor; • water removal; • methane conditioning; and • recycled fuel must be demonstrated as an integrated operating system. 5.4 Hydrogen balance Hydrogen demand must be validated under realistic operating conditions, including: • syngas-derived hydrogen; • supplementary renewable or low-fossil hydrogen; • transient operation; • process losses; and • hydrogen required to compensate for carbon-cycle losses. 5.5 Energy balance A complete integrated energy balance must confirm the relationship between: • fuel energy; • gross electrical output; • internal power consumption; • hydrogen-production demand; • CO₂ capture demand; • compression; • oxygen production where applicable; • methanation heat; • recovered thermal energy; and • exportable electricity and heat. 5.6 Dynamic operation The carbon loop must be demonstrated during: • start-up; • normal operation; • load changes; • shutdown; • restart; • temporary capture interruption; • methanator interruption; • hydrogen-supply variation; and • abnormal process conditions. 5.7 Carbon-loss accounting A defensible CRT demonstration must measure rather than merely calculate carbon losses. Relevant measurements should include: • stack carbon; • purge streams; • fugitive methane; • vented CO₂; • process drains where applicable; • start-up/shutdown releases; and • carbon entering or leaving stored inventories. 6. Preliminary Integrated-System TRL Position Based on CEWT’s current project-development status, the overall CRT/CCMS architecture should not presently be represented as TRL 7, 8 or 9. The individual constituent technologies are predominantly high-TRL technologies. However, the complete CEWT carbon-recirculation architecture has not yet been demonstrated as an operating integrated plant at commercially relevant scale. A defensible present description is therefore: CRT/CCMS is an integrated system architecture built predominantly from high-TRL industrial technologies, while the integrated carbon-recirculation configuration itself remains at pre-commercial demonstration readiness. For internal planning purposes, CEWT should presently treat the integrated CRT/CCMS system as approximately TRL 4–5, subject to independent review of the available engineering evidence. This rating recognises that: • the process architecture has been defined; • stoichiometric relationships have been developed; • material and energy balances have been developed; • major equipment categories have been identified; • established technology suppliers are being engaged; • project-specific engineering is progressing; and • a commercial-scale demonstration project is being developed. It also recognises that: • no complete CRT/CCMS loop has yet operated; • integrated steady-state performance has not yet been demonstrated; • dynamic carbon inventory management has not yet been demonstrated; • measured carbon-loss performance is not yet available; • long-duration operating stability has not yet been established; and • integrated performance guarantees have not yet been demonstrated. The TRL 4–5 designation should therefore be treated as a provisional integrated-system assessment, not as an externally certified rating. 7. Proposed CRT/CCMS TRL Progression Current stage — approximately TRL 4–5 Evidence should include: • defined process architecture; • process-flow diagrams; • overall mass balance; • overall energy balance; • principal reaction stoichiometries; • equipment list; • preliminary controls philosophy; • preliminary operating philosophy; • process simulations; • vendor engagement; • preliminary safety assessment; and • identification of all significant carbon entry and exit points. Next objective — TRL 6 CEWT should target TRL 6 through an integrated pilot or demonstration system operating in a relevant process environment. The demonstration should physically integrate, at minimum: 1. carbon-containing fuel input; 2. controlled energy conversion or representative combustion; 3. CO₂ recovery; 4. CO₂ conditioning; 5. H₂-rich gas supply; 6. methanation; 7. water removal; 8. methane/RSNG conditioning; 9. fuel recycle; 10. continuous carbon-flow measurement; and 11. integrated process control. The critical result would not simply be methane production. It would be evidence of continuous carbon recirculation through the complete process sequence. Commercial demonstration objective — TRL 7 TRL 7 should correspond to operation of an integrated CRT/CCMS demonstration under conditions representative of the intended commercial application. The demonstration should establish: • continuous operation; • representative scale; • validated carbon balance; • measured capture efficiency; • measured carbon losses; • hydrogen consumption; • electrical parasitic load; • methane-production performance; • fuel-quality stability; • transient response; • safety-system performance; • start-up/shutdown procedures; • reliability; and • preliminary operating cost. Achieving this milestone would be particularly important because commercially oriented carbon markets and financiers increasingly associate TRL 7+ with credible delivery capability. TRL 8 TRL 8 should require completion and qualification of the integrated commercial system design together with sufficiently extensive demonstration evidence to support: • final engineering; • vendor guarantees; • EPC contracting; • financing due diligence; • permitting; • operating procedures; • performance testing; and • independent engineering review. At this stage, residual risk should principally be project-execution risk rather than fundamental technology-integration risk. TRL 9 TRL 9 should only be claimed after CRT/CCMS has operated successfully as a complete commercial system under normal industrial conditions. Evidence should include sustained operation demonstrating: • carbon recovery; • carbon recirculation; • system reliability; • operating availability; • process safety; • fuel quality; • carbon-loss performance; • hydrogen consumption; • internal energy demand; • maintenance requirements; and • commercial operating performance. 8. Critical Distinction: Technology Risk vs Integration Risk The principal CRT development risk should be described as integration and system-performance risk, rather than fundamental scientific risk. A conventional early-stage technology may require proof that a new physical phenomenon, catalyst, material or reactor can perform its intended function. CRT is different. Most of the physical transformations required by CRT already occur commercially in separate industrial processes. The development question is therefore: Can these established process operations be integrated, controlled and economically operated so that carbon functions as a repeatedly circulating system inventory while external fossil-carbon make-up is progressively reduced to the amount required to compensate for unavoidable losses? This distinction materially affects how the project should be assessed by: • investors; • governments; • lenders; • insurers; • EPC contractors; • technology licensors; and • independent engineers. 9. Proposed Technology Readiness Matrix CEWT should maintain a formal Technology Readiness Matrix for every demonstration project. Each subsystem should be scored against the following categories: Category Evidence required Technology maturity Existing commercial installations and operating references Scale maturity Evidence at comparable throughput Feed compatibility Demonstration with relevant gas composition Product specification Ability to meet required outlet specifications Integration maturity Evidence of operation with upstream/downstream CRT systems Dynamic performance Start-up, shutdown and load-following behaviour Safety maturity HAZID/HAZOP/SIL and operating safeguards Vendor guarantee Availability and scope of performance guarantee Commercial maturity Budget price, schedule and contractual availability Carbon-accounting maturity Ability to measure all material carbon flows Energy-performance maturity Demonstrated auxiliary-energy consumption Project readiness Engineering, permits, procurement and constructability 10. Evidence Register Every TRL claim should ultimately be supported by an evidence register containing, where available: • patents and patent applications; • engineering calculations; • process simulations; • BFDs; • PFDs; • UFDs; • P&IDs; • heat and material balances; • equipment data sheets; • vendor correspondence; • technology-provider proposals; • test reports; • pilot operating data; • independent engineering reports; • HAZID studies; • HAZOP studies; • SIL assessments; • emissions measurements; • carbon-flow measurements; • energy-consumption measurements; • product-gas analyses; • reliability data; • performance guarantees; and • commercial operating records. No TRL advancement should be based solely on narrative description. 11. Recommended CEWT Public Position Until an independent readiness assessment has been completed, CEWT should avoid statements such as: “CRT is TRL 8.” or “CRT is commercially proven.” A more defensible formulation is: CEWT’s Carbon Recycling Technology integrates predominantly mature industrial technologies including power generation, carbon capture, synthesis-gas production, methanation, compression, heat recovery and industrial process control. The principal development requirement is demonstration and validation of these technologies as an integrated carbon-recirculation system. For more technically sophisticated audiences: CRT has a high component-level technology readiness but a lower integrated-system readiness. CEWT’s demonstration programme is specifically intended to close that integration-readiness gap and establish measured carbon, hydrogen and energy performance under commercially relevant operating conditions. 12. Strategic Objective CEWT’s technology-development programme should therefore be structured around one clear objective: Move CRT from high component maturity but pre-commercial integrated-system readiness to TRL 7+ through measured demonstration of the complete carbon-recirculation loop. This is more credible than attempting to argue that CRT is already commercially mature. It also creates a clear development narrative: Established technologies
→ engineered integration
→ integrated demonstration
→ measured carbon circulation
→ independent validation
→ vendor guarantees
→ bankability
→ commercial deployment. 13. Preliminary Conclusion The present technology-readiness position of CRT/CCMS can be summarised as follows: Underlying industrial technologies: predominantly high TRL. CRT process architecture: substantially defined at engineering/concept-development level. Complete integrated CRT/CCMS loop: not yet demonstrated. Provisional overall integrated-system position: approximately TRL 4–5, pending formal independent assessment. Immediate development target: TRL 6 through integrated pilot/demonstration operation. Critical commercial threshold: TRL 7+, supported by relevant-scale operating evidence and independently verified carbon and energy balances. Ultimate objective: TRL 8–9 commercial qualification and operation. The central proposition is therefore: CRT does not require every industrial technology within the plant to be reinvented. It requires the integrated carbon-recirculation architecture to be demonstrated. That distinction should form the foundation of CEWT’s technology-readiness, demonstration and bankability strategy. Ref : Carbon Gap (European Carbon Managment Guide)

FOLLOW THE CARBON — For Engineers, Policymakers and Investors

FOLLOW THE CARBON — For Engineers, Policymakers and Investors When a new energy technology is presented, the first question should not be: Is it green? Is it renewable? Is it net zero? Start with thermodynamics. Define the system. Define the surroundings. Draw the boundary. Then identify what crosses that boundary. Follow the mass. Follow the energy. And specifically, follow the geological carbon. Every energy system can be examined this way. Step 1 — Start with the basic process Mass + Energy Input → Process → Mass + Energy Output Nothing controversial here. It is simply a defined system and its flows. Step 2 — Ask what happens to the output If an output can be recovered, converted and returned as an input: Input → Process → Output → Recovery → Conversion → Recycled Input ↻ A linear material flow has become a circulation loop. Step 3 — Follow carbon and energy separately This distinction is essential. Carbon can circulate as an inventory. Energy must continue to flow through the system. Energy is required for conversion, capture, compression, hydrogen production, pumps and other processes. There are unavoidable thermodynamic losses. There is no claim of perpetual energy. Step 4 — Now examine Carbon Recycling Technology (CRT) Follow the carbon: Carbon-containing fuel → Energy conversion → CO₂ → Capture → Conversion → Recycled carbon-containing fuel → Energy conversion ↻ Do not stop following the carbon when it becomes CO₂. Continue following it. Then ask: How much fresh geological carbon must continuously cross the external system boundary once the circulating carbon inventory has been established? That is the important question. For engineers Don’t accept the claim. Check the process flow diagram. Check the mass balance. Check the energy balance. Check the capture efficiency, conversion efficiency, purge streams, losses, auxiliary energy and make-up requirements. Does the balance close? For policymakers Don’t begin with labels. Ask: How much fresh geological carbon enters the defined boundary? How much carbon leaves for the atmosphere? How much is recovered and circulated? What energy must continuously enter from outside? This provides a physical basis for distinguishing decarbonisation from defossilisation. For investors The questions become equally straightforward. Can the system provide dispatchable energy over infrastructure-scale operating life? Can operational carbon emissions be reduced to very low levels? Can dependence on continuous fresh geological-carbon supply be progressively reduced toward the make-up required for unavoidable losses? And can all of this be demonstrated economically at commercial scale? If so, the investment question becomes worth examining. The CRT proposition is testable We are not asking engineers, policymakers or investors simply to believe that CRT leads toward defossilisation. Define the boundary. Follow the geological carbon. Follow the energy. Check the balances. If the balances do not close, challenge the proposition. If they do close, follow the logic to its conclusion. That conclusion is defossilisation. #FollowTheCarbon #FollowTheEnergy #Defossilisation #CarbonRecycling #CRT #Thermodynamics #EnergyTransition #CircularCarbon #CleanEnergy #IndustrialDecarbonisation

Singapore Integrated Urban Food Infrastructure Initiative

Concept Brief – Feasibility and Validation Program Opportunity Land-constrained cities face a growing challenge: how to strengthen food resilience without increasing dependence on land, water, and increasingly complex external supply chains. Controlled-environment vertical farming offers one pathway, but its potential should be considered as more than an agricultural technology. CEWT proposes evaluating an integrated urban food infrastructure platform in which dependable energy, controlled agriculture, cooling, water recovery and controlled carbon dioxide utilisation are designed as one interconnected system. Integrated concept Dependable Energy → Controlled Agriculture → Local Food Advanced Cooling + Water Recovery + Controlled CO₂ Utilisation + Heat Recovery Multi-level cultivation can substantially increase productive growing area within a limited physical footprint. Environmental control enables year-round production, while hydroponic water recirculation and recovery of moisture removed during dehumidification create opportunities to reduce net water requirements. Controlled quantities of suitably conditioned CO₂ may also be supplied to the growing environment as a productive biological input. Rather than designing each requirement independently, the objective is to optimise the complete energy–water–carbon–food system. Proposed feasibility and validation program CEWT proposes an initial Singapore-based feasibility and validation program bringing together appropriate scientific, engineering, infrastructure and commercial expertise. • suitable crops and realistic production yields; • multi-level cultivation configuration and land productivity; • lighting and electrical-energy requirements; • cooling, humidity control and environmental management; • plant transpiration and condensate-water recovery; • hydroponic water and nutrient recirculation; • controlled CO₂ enrichment requirements; • opportunities for useful heat recovery; • potential integration with existing urban infrastructure; • CAPEX, OPEX and production cost; and • commercial scalability and contribution to urban food resilience. Potential 1 MW demonstration Subject to successful scientific, engineering and commercial validation, the program could progress to a potential 1 MW integrated demonstration facility. Preliminary CEWT engineering screening indicates that a 1 MW-class module could potentially support approximately 9,000 m² of effective multi-level cultivation area and production in the order of 700 tonnes per year of leafy vegetables. These are preliminary engineering screening estimates only and are specifically intended to be tested and refined through the proposed feasibility and validation program. The demonstration would evaluate the complete integrated system rather than simply the agricultural production component. Development pathway Feasibility → Scientific Validation → Engineering & Commercial Assessment → Potential 1 MW Demonstration → Replication The initial objective is therefore not to propose construction of another vertical farm. It is to determine whether integrated design can materially improve the technical and commercial performance of controlled urban agriculture by managing energy, cooling, water and carbon as interconnected resources. Strategic proposition Land and resource constraints can become drivers of infrastructure innovation. A successful demonstration could establish a replicable model for highly urbanised and resource-constrained cities seeking greater resilience from limited physical resources. Energy → Water → Carbon → Food An integrated infrastructure platform for resilient cities. Clean Energy and Water Technologies Pty Ltd (CEWT) | Melbourne, Australia Ahilan Raman | Managing Director | ahilan@cewt.tech

Defossilisation – The Next Chapter of the Energy Transition

Defossilisation – The Next Chapter of the Energy Transition Part 4: Hydrogen Powers the Future; Carbon Enables the Cycle The energy transition is increasingly looking to hydrogen as a future energy carrier. That direction has merit—but hydrogen alone does not answer one of the more fundamental questions facing the transition: What do we do with carbon? Carbon is not inherently the problem. Carbon is an essential element in fuels, chemicals, materials, agriculture and life itself. The deeper problem is our continuing dependence on new geological carbon extracted from coal, oil and natural gas and transferred into the active carbon cycle. This distinction is increasingly entering mainstream scientific discussion. In January 2026, Nature argued explicitly that achieving net zero means eliminating dependence on fossil sources rather than eliminating carbon itself, noting that carbon-based fuels and carbon-containing products will remain necessary in a net-zero economy. That is where hydrogen and circular carbon potentially become complementary. Hydrogen supplies energy. Carbon provides a carrier. Renewable hydrogen can provide chemical energy without introducing new carbon into a process. But hydrogen is difficult and costly to store, transport and integrate into some existing industrial and energy infrastructure. Carbon, by contrast, can form highly useful molecules such as methane and methanol. Instead of treating captured CO₂ simply as a waste requiring disposal, we can ask a different engineering question: Can recovered carbon become an inventory that is repeatedly circulated? For methane synthesis, the underlying chemistry is well established: CO₂ + 4H₂ → CH₄ + 2H₂O Hydrogen supplies the reducing energy. Carbon provides the molecular framework for the methane. The resulting methane can then be stored, transported and used through established gas infrastructure. If its carbon is subsequently recovered rather than continuously released, that carbon can potentially be returned to the synthesis process. The conceptual cycle becomes: Renewable electricity → H₂ → recovered carbon + H₂ → synthetic methane → useful energy → carbon recovery → synthetic methane again The important input progressively becomes energy, rather than replacement fossil carbon. Follow the carbon, not merely the fuel label Consider two methane molecules. Chemically they may be identical. One molecule may contain carbon freshly extracted from a geological gas reservoir. The other may contain carbon recovered from an engineered process and circulated for its second, tenth or hundredth cycle. Calling both simply “natural gas” or “methane” misses the fundamental difference in their carbon pathways. This is why I believe future energy accounting needs to examine three things separately: Fossil Carbon Intensity (FCI) — how much fresh geological carbon enters the system. Carbon Circularity (CC) — how effectively recoverable carbon is retained and reused. Carbon Emissions Intensity (CEI) — how much ultimately reaches the atmosphere. A system can therefore improve its carbon performance not merely by changing the fuel label, but by progressively reducing the amount of new fossil carbon crossing its system boundary. We can express that transition through a simple measure: Defossilisation Progress (%) = 100 × [1 − (FCI / FCI₀)] where FCI₀ represents the fossil-carbon intensity of the reference system. At the starting point, FCI = FCI₀ and defossilisation progress is zero. As recovered carbon increasingly substitutes for newly extracted carbon, FCI declines. If fresh geological carbon input eventually becomes negligible, defossilisation approaches 100%. Renewable hydrogen becomes increasingly important There is another reason to distinguish hydrogen from carbon. Today, global hydrogen production itself remains overwhelmingly fossil-based. The IEA reports that global hydrogen demand exceeded 100 million tonnes in 2025, while low-emissions hydrogen production was still below 1 million tonnes. Electrolysis capacity is growing rapidly, but low-emissions hydrogen represents only a little over 1% of expected global production in 2026. So simply saying “hydrogen” does not establish defossilisation. We must also follow the hydrogen. As renewable hydrogen expands, however, an interesting possibility emerges. Renewable hydrogen can increasingly provide the energy required to convert recovered CO₂ and CO back into useful carbon-based energy carriers. The transition can therefore move in two directions simultaneously: Fresh fossil carbon ↓ Renewable hydrogen ↑ while the existing carbon inventory continues circulating. This changes how we think about carbon capture Traditional carbon capture discussions often end at: Capture → transport → permanent storage. Permanent geological storage will undoubtedly have applications. But there is another pathway: Capture → recover → regenerate → reuse. These approaches need not be competitors. Different carbon streams will require different solutions. The important conceptual change is to stop assuming that every captured carbon atom is necessarily waste. Some carbon may be permanently stored. Some may become chemical feedstock. Some may become materials. And some may potentially remain within deliberately engineered energy cycles. This broader idea is gaining attention beyond energy systems. Research published in 2026 is examining the replacement of fossil feedstocks with alternative carbon sources—including captured CO₂—in industrial clusters, while Nature has described the need for sustainable non-fossil sources of carbon for the chemical economy. The destination is not a carbon-free civilisation Such a civilisation is neither realistic nor desirable. The destination should instead be an economy that requires progressively less new geological carbon. Hydrogen can supply increasing amounts of the energy required to make that possible. Carbon can continue doing what carbon does exceptionally well: forming molecules, carrying energy and providing essential industrial feedstocks. But rather than continually extracting it, using it once and releasing it, we should increasingly ask whether we can manage carbon as an inventory. That leads to a different vision of the energy transition: Hydrogen powers the future. Carbon enables the cycle. Defossilisation determines whether we have actually broken our dependence on fossil extraction. The next chapter will examine how this principle can move from a framework into an engineered system through Carbon Recycling Technology (CRT). #Defossilisation #EnergyTransition #Hydrogen #CircularCarbon #CarbonManagement #CarbonRecycling #SyntheticFuels #NetZero #CleanEnergy #CEWT Sources: Nature, 6 January 2026 and 18 February 2026; International Energy Agency, Global Hydrogen Review 2026, published 18 June 2026; Scientific Reports, 26 January 2026.