Why electricity efficiency alone does not determine the economic value of sustainable data-centre infrastructure
Clean Energy and Water Technologies Pty Ltd (CEWT)
Introduction
The rapid expansion of artificial intelligence and digital infrastructure is creating unprecedented demand for reliable electricity, cooling and supporting utilities.
Meeting these requirements through conventional infrastructure can require substantial investment in electricity generation, transmission, energy storage, and cooling systems.
At CEWT, we are developing Carbon Recycling Technology (CRT) as an alternative integrated energy architecture.
Our proposed 20 MW CRT trigeneration system is designed to combine dispatchable electricity generation, carbon recycling, useful heat recovery, cooling, and water reuse.
The objective is not simply to improve the electrical efficiency of an individual machine.
It is to improve the economic and environmental performance of the complete energy system.
1. From carbon emissions to carbon circulation
Conventional natural-gas power generation releases CO₂ as a combustion product.
Carbon capture and storage seeks to prevent atmospheric emissions by capturing and permanently storing that CO₂.
CRT proposes another pathway.
Carbon dioxide recovered from the electricity-generation process is combined with hydrogen-rich syngas and renewable hydrogen to regenerate methane.
The regenerated methane can subsequently be reused for electricity generation.
The simplified methanation reactions are:
CO+ 3 H2=> CH4 + H2O and CO2 + 4 H2=> CH4 + 2 H2O
The central concept is to maintain carbon as a circulating material inventory within the integrated thermodynamic system.
Renewable hydrogen supplies the energy required for carbon recycling.
The objective is to minimise the continuous introduction of new fossil carbon while compensating for unavoidable process losses.
Achieving this requires a verified carbon balance, high capture efficiency and appropriate carbon makeup.
2. Continuous electricity for AI data centres
CEWT’s proposed 20 MW trigeneration demonstration is intended to provide firm electricity for a continuously operating data centre.
The current equipment configuration under evaluation comprises five Jenbacher gas engines proposed by Clarke Energy.
| Engineering parameter | Full-load design basis |
| Installed electrical capacity | 22.5 MW |
| Electrical efficiency | 46.2% |
| Fuel energy input | 48.715 MW |
| Recoverable thermal energy | 21.840 MW |
These figures are based on Clarke Energy’s quoted full-load engine performance.
The difference between gross electrical generation and the data-centre load must accommodate the appropriate auxiliary loads.
The wider CRT plant, including hydrogen production, reforming, CO₂ recovery and methanation, requires its own complete energy balance.
3. Turning recovered heat into a useful resource
Electricity generation inevitably produces thermal energy.
In many conventional arrangements, much of this heat is rejected to the environment.
Clarke Energy’s engine configuration offers approximately 21.84 MW of recoverable heat at full load.
This includes heat recovered from exhaust gases, engine jacket water, lubricating oil, and intercooling.
CRT also incorporates exothermic methanation reactions that release thermal energy.
These sources create opportunities for integrated heat management.
Potential applications include steam generation, process-water heating and absorption chilling.
For AI data centres, absorption chilling is particularly interesting because it can potentially reduce the electrical energy required for cooling.
However, the actual cooling capacity depends on the available heat temperatures, chiller performance, and the facility’s cooling requirements.
4. Renewable electricity and the thermodynamic trade-off
Hydrogen production through electrolysis requires substantial electricity.
Additional energy is required for reforming, compression, carbon dioxide recovery, and other process operations.
Consequently, the electricity-to-hydrogen-to-methane-to-electricity pathway has lower round-trip electrical efficiency than direct renewable electricity use or battery storage.
This is a fundamental thermodynamic consideration.
CRT therefore needs to be evaluated according to the services it provides beyond electricity alone.
These include dispatchable generation, long-duration chemical energy storage, useful heat, cooling and carbon management.
The economic value of these services must be established through transparent engineering and financial modelling.
5. Water as part of the integrated resource balance
Water is both consumed and produced within the CRT process.
Electrolysis consumes purified water to generate hydrogen and oxygen.
Steam reforming requires process steam.
Methanation and methane combustion produce water that may be recovered through condensation.
CEWT’s proposed design therefore includes an integrated water-management approach.
The objective is to maximise practical recovery and reuse while minimising external water demand.
The net water balance must account for all consumption, generation, treatment and discharge streams.
6. Business as Usual versus CRT: The financial question
The commercial justification for CRT must come from a fair comparison against conventional alternatives.
CEWT has developed preliminary comparative financial models examining the potential value of integrated trigeneration.
The financial assessment considers:
| Business as Usual | Integrated CRT |
| Electricity supply and firming | Dispatchable recycled-methane generation |
| Conventional cooling systems | Potential heat-driven absorption chilling |
| Separate energy-storage infrastructure | Integrated batteries and methane storage |
| Conventional emissions management | CO₂ capture and methanation |
| External water supply and treatment | Potential process-water recovery and reuse |
| Separately optimised infrastructure | Integrated electricity, carbon, heat and water management |
The models assess the combined economic contribution of these functions.
Importantly, the benefits must not be double-counted.
For example, the same recovered heat cannot simultaneously be credited as both useful steam and cooling energy.
Similarly, the value of recycled methane must be reconciled with hydrogen production costs and electricity-generation revenues.
CEWT’s earlier financial screening indicates that integration may create significant additional value.
However, these results remain preliminary and are being updated using vendor-specific engineering data.
7. The next stage of technical and commercial validation
CEWT is undertaking a detailed reconciliation of the Clarke Energy engine data and Linde’s hydrogen-rich syngas information.
The purpose is to establish consistent carbon, hydrogen, energy and water balances.
The revised financial model will compare conventional and CRT configurations over a full 8,760-hour operating year.
Key financial measures will include capital expenditure, operating costs, net present value, internal rate of return, debt-service coverage and sensitivity to renewable hydrogen costs.
The objective is to determine whether CRT can deliver a measurable commercial advantage while satisfying the operational requirements of a modern AI data centre.
Conclusion: A systems approach to sustainable energy
The energy transition is not solely about replacing one source of electricity with another.
It is also about how effectively energy and materials are integrated, stored, recovered and reused.
Carbon Recycling Technology proposes a system in which carbon acts as a circulating material carrier, renewable hydrogen provides energy for methane regeneration, and recovered thermal energy supports additional useful services.
For AI data centres, this offers a potential pathway towards integrated, dispatchable energy infrastructure.
The ultimate measure of success will not be an isolated conversion-efficiency figure. It will be the verified economic and environmental performance of the complete system.
Clean Energy and Water Technologies Pty Ltd (CEWT)
Carbon Recycling Technology — Integrated Energy, Carbon and Water Management
