Commercial energy / Buyer guidance
Find unexplained electricity use without confusing it with electrical leakage
Separate after-hours consumption from electrical faults, with a safe interval-data investigation and an original baseline example.
First distinguish a billing question from a safety fault
“Electricity leak” is often used casually to describe energy used when a building appears idle. That is not a diagnosis of electrical leakage, insulation failure or a grounding fault. Electrical defects belong with qualified personnel. A procurement spreadsheet, smart plug or browser tool cannot establish that equipment is safe.
For an unexpectedly high invoice, begin with the period, meter, read status, units and rates. For an unexplained overnight load, begin with interval data and an authorized operating inventory. Do not open energized equipment or disable protective systems to chase a possible cost reduction. If there is an immediate electrical hazard, use the facility's emergency procedure and the relevant utility or emergency response channel.
Establish the expected after-hours load
Refrigeration, security, servers, ventilation, pumps, freeze protection and tenant operations can legitimately remain active. List these loads with the responsible operator. Compare similar nights, weekends and weather conditions. A step change around an equipment addition or schedule override can help identify a question for investigation; it does not prove a fault or waste.
DOE's re-tuning method uses building automation data to investigate control opportunities. Use that principle to test schedules and overrides with the operator. Preserve a baseline before changing settings so a later result can be interpreted.
Worked example: quantify an unexplained baseline before assigning a cause
Independently constructed example: interval records show a stable 24 kW overnight load. The approved operating inventory explains 18 kW. The unexplained difference is 6 kW. Across 12 hours per night for 30 nights, that difference represents 6 × 12 × 30 = 2,160 kWh.
At an assumed marginal energy component of $0.11/kWh, the scenario amount is $237.60. It is not an achieved saving and not proof that 6 kW can be removed. Meter timing, an omitted tenant load or equipment cycling could explain the difference. Any demand effect also depends on whether the load contributes to the billed peak. Preserve these uncertainties rather than presenting the scenario amount as a recovery target.
Test one explanation at a time
| Observation | Check with the responsible team |
|---|---|
| Load starts before occupancy | Approved warm-up schedule and recovery need |
| Load persists on holidays | Calendar, overrides and legitimate continuous use |
| Sudden permanent step | New equipment, tenant change or meter boundary |
| Use spikes only in severe weather | Heating, cooling and freeze-protection operation |
| Invoice differs from interval sum | Billing period, estimated data and multiplier |
Document who approved each test, what changed, when and which service constraints were protected. Compare the next relevant operating periods using the same meter boundary. Lower cost can result from a rate change even if use did not change, so report kWh and dollars separately.
Sources and limits
DOE re-tuning supports a controls-data investigation. ENERGY STAR benchmarking supports contextual comparison. The numerical example is an original diagnostic scenario, not an electrical safety procedure, case study or savings claim.