The meter pays for itself only if its data changes a costly decision. Start with billing peaks and net generation cost.
Contents
| Question | Measurement that answers it | Commercial consequence |
|---|---|---|
| Are we setting a new billing peak? | Utility-aligned demand interval at the service | Avoid dispatching too late or measuring the wrong load. |
| Is this generator saving money? | Net kWh delivered, gas consumption and dispatch hours | Calculate fuel and maintenance cost per useful kWh. |
| Which process is consuming spare capacity? | Time-aligned feeder and main demand | Find the constraint before buying more generation. |
| Can tenants be billed from this data? | Approved settlement arrangement and audit trail | Avoid a billing dispute over unaccepted readings. |
A fifteen-minute mistake can cost more than the meter
Suppose a hypothetical tariff charges $12/kW-month on the monthly peak. A 300 kW process running during the peak adds $3,600 for that month. Moving the same energy to a different interval could avoid that increment; merely reducing total daily kWh might not. The first useful screen is a plot of interval demand against the actual billing rule.
An average 15-minute target also needs action before the interval ends. At minute ten, an accumulated average of 2,200 kW means 22,000 kW-minutes have already been used. To finish the interval at 2,000 kW, the remaining five minutes must average no more than 1,600 kW: (2,000 × 15 − 2,200 × 10) ÷ 5. A meter that reports only after the interval closes cannot support that response.
Measure net generation, not just the impressive number
A 2 MW generator producing for 100 hours makes 200 MWh at its terminals. If pumps, fans and other plant loads consume 10 MWh, only 190 MWh reaches the useful-load boundary. At an assumed $24,000 combined fuel and variable maintenance cost, generation costs $126/MWh delivered, not $120/MWh. The 5% auxiliary load changes the economic comparison.
Record generator kWh, site import/export and gas on synchronized clocks. Check gas pressure, standard-volume conversion and heating-value basis before dividing fuel dollars by electrical output. If dispatch is driven by demand charges, retain the exact interval data behind the bill.
Spend on the data path you will actually use
For monthly accountability, a reliable interval export may be enough. Automatic peak control needs timely readings, communications failure detection and a controller with an explicit fallback. Revenue billing adds approved meters, configuration control and retained audit records. Buying the most expensive meter does not fix an incorrect CT ratio or a timestamp offset.
The procurement sheet should name the measurement point, voltage and current range, CT/PT ratios, accuracy class, interval convention, clock synchronization, protocol and data owner. Require an end-to-end commissioning comparison against a known reference. That proves the complete measurement chain rather than just the meter on the bench.
Start with one bill and one week of interval data
Mark the bill’s charge-setting interval, identify the controllable loads running then, and calculate the value of reducing them. That tells you whether the next dollar belongs in metering, controls, a generator or a change to the operating schedule.