Energy efficiency: define a baseline before counting savings
What would have happened without the change?
IEA’s report discusses energy efficiency at a broad scale. A site project needs its own baseline: the service delivered, energy used, period and relevant conditions. Lower energy intensity and lower total consumption are different results. A factory can use less energy per unit while using more overall because it produces more.
A baseline record
| Field | Record |
|---|---|
| Service | Product quantity, floor area, occupancy or another relevant activity |
| Energy | Meter, fuel, units and period |
| Conditions | Weather, hours, output mix and equipment state |
| Change | Installation date, operating settings and maintenance |
| Cost | Equipment, installation, disruption, service and replacement |
| Evidence | Readings, adjustment method and unresolved effects |
A fictional constant-activity comparison
At the same stated activity, fictional energy use falls from 100 to 90 units. The simple reduction is (100 − 90) ÷ 100 = 10%. If output rises from 100 to 120 product units while energy rises to 108, total energy increases 8%, although intensity falls from 1 to 0.9 energy units per product. These are different statements. Weather or operating changes would need further adjustment before attributing the whole effect to a project.
Do not buy a percentage without its boundary
Request the assumptions behind a saving estimate and compare them with the site’s actual operation. Track both energy and delivered service after installation. A simple payback omits financing, changing rates and performance uncertainty unless explicitly included. The worksheet supports a scoped comparison; it does not establish that an unmeasured improvement is always the cheapest option.
Sources and scope
- IEA: Energy Efficiency 2025 — Dated global context; not measured savings or costs for a specific site.
Sources checked October 10, 2026. AI-assisted research and drafting. The examples, calculations and worksheets are Luminesca editorial work; they are not measured trials, first-hand reporting or an independent certification. Removed the claim that every efficiency project is cheaper than new generation. Report a specific correction with its source.