ECO.10:5 - Archetypal Grounding

ECO.10:5.1 - Half the energy per unit

A constructed process would produce 100 equivalent units at 2 kWh each without an improvement: 200 kWh. The improved process uses 1 kWh per unit. At unchanged output its fixed-output saving is 100 kWh.

If the improvement induces output of 150 units, total use is 150 kWh and the actual saving is 50 kWh. Half the fixed-output saving is offset: rebound is 50%. At 220 units total use is 220 kWh; actual saving is −20 kWh, so rebound is 120%, the backfire case. The break-even output is 200 units.

These are conditional arithmetic cases. If output without the improvement would already have risen to 180 units, the relevant counterfactual is 360 kWh, not 200. Observing 220 improved units against an earlier year’s 100 does not by itself demonstrate backfire.

Now suppose the declared account also includes 150 kWh for the new equipment and transition in the same period, absent from the no-improvement alternative and incurred regardless of output. The three totals at an induced volume of 150 are 200, 250 and 300 kWh. Fixed-output saving is −50 kWh; the response adds a further 50 kWh. Total use rises by 100 kWh, but this account has no positive saving whose offset can be expressed as a rebound percentage. The operating efficiency gain remains real; the broader total separates its additional burden from the demand response.

ECO.10:5.2 - An AI task becomes cheaper

A firm reduces the cost per accepted analysis and considers using the saving for more analyses. Token count is not the useful-result unit if acceptance, human revision or result quality also changes. The firm compares cost and resource use per accepted result, possible volume and the receiving work’s value.

A fixed budget can increase the number of useful analyses without lowering expenditure. Electricity or hardware use may move differently from expenditure. Calling every such change “Jevons” would hide the actual consequence the decision needs.