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Page 3 Notes on representing the numbers
| EMISSIONS ACCOUNTING vs THERMODYNAMIC ANALYSIS | ||
| Why the DUKES 1/3:2/3 Method Obscures Real Benefits | ||
| DUKES Accounting Method | Thermodynamic Reality | |
| What it measures | Allocated emissions per output type | Actual energy flows and efficiency |
| Heat fuel allocation | 1/3 of fuel 'goes to' heat | No allocation - single combustion process |
| Electricity fuel allocation | 2/3 of fuel 'goes to' electricity | No allocation - single combustion process |
| Shows efficiency as | Implied separate efficiencies | Overall system efficiency (80-90%) |
| Primary benefit visible? | Hidden in accounting conventions | Clear: fuel saved vs separate generation |
| CO2 savings calculation | Complex with allocation assumptions | Simple: less fuel burned = less CO2 |
| Useful for | Tax relief calculations, emissions reporting | Engineering decisions, true performance |
| Misleading because | Suggests fuel is 'divided' between outputs | Shows actual thermodynamic advantage |