Commercial energy / Buyer guidance
Commercial energy worked examples: evaluate evidence before claiming savings
Distinguish a scenario, a corrected invoice and a measured result. Includes examples of price-volume decomposition and production-normalized energy.
What these examples can and cannot establish
This page presents independently constructed examples, not anonymized clients or completed transactions. A plausible calculation is not evidence that a business achieved the result. To describe an actual outcome, retain the baseline, intervention, reporting period, supporting records and explanation of other changes.
Three evidence labels are useful. A planning scenario estimates what would happen under stated inputs. An invoice reconciliation checks a charge against governing documents. A measured performance result compares an observed reporting period with an appropriate baseline. They answer different questions and should not share a generic “savings” label.
Worked example: lower use with a higher cost
Hypothetical energy-only figures: baseline consumption is 60,000 kWh at $0.10/kWh, costing $6,000. Reporting-period use is 57,000 kWh at $0.12/kWh, costing $6,840. Consumption fell by 3,000 kWh, or 5%, while cost increased by $840, or 14%.
One clear decomposition holds the old rate for the volume change: −3,000 × $0.10 = −$300. It then prices the rate change at reporting-period volume: 57,000 × $0.02 = $1,140. The two effects sum to the $840 increase. Other valid decompositions allocate interaction differently, so state the chosen method. Neither component proves that a facility project caused the change in use.
Compare production as well as energy
A second hypothetical facility uses 80,000 kWh to make 10,000 units, or 8 kWh per unit. Later it uses 90,000 kWh for 12,500 units, or 7.2 kWh per unit. Total energy rose by 12.5%, while the simple intensity metric fell by 10%.
At the old intensity, 12,500 units would imply 100,000 kWh. The reporting period is 10,000 kWh below that simple comparison. But the production mix, fixed baseload, shifts and weather may differ. Calling all 10,000 kWh a verified project saving would require a defensible baseline and adjustment method. A ratio is a screening measure, not an automatic measurement-and-verification plan.
Choose a relevant measurement boundary
For a restaurant, document meal periods, kitchen schedules and refrigeration. For a hotel, document occupancy, laundry and weather. For manufacturing, document output, process changes and downtime. Schools require term, holiday and summer-use records. A portfolio needs consistent meter boundaries and dates before totals can be compared.
Use the individual industry guides for operating questions. Keep rate procurement, consumption efficiency, demand management, one-time credits and incentive payments on separate lines. Do not count a supplier rate change again as a facility efficiency benefit.
Evidence checklist for publishing a real result
| Required record | Question it resolves |
|---|---|
| Baseline and reporting invoices/data | What was actually observed? |
| Meter and equipment boundary | Which loads are included? |
| Operating and weather record | What else changed? |
| Intervention date and work record | What action is being evaluated? |
| Calculation and adjustments | Can another reviewer reproduce it? |
| Permission and confidentiality review | Can the result be disclosed? |
Sources and limits
DOE measurement-and-verification options distinguishes measurement approaches. ENERGY STAR benchmarking guidance supports contextual comparison. All figures here are original teaching assumptions; no typical saving, customer outcome or guaranteed result is represented.