How a promise is measured.
Every HawaOS promise is a number, a method and a remedy. This page is the method, in the detail your energy manager and your auditor will want, so that a saving we report is one you can defend.
1. What is metered
The kit measures the station, not the plant. Everything a promise depends on has its own instrument.
| Quantity | Instrument | Interval | Where |
|---|---|---|---|
| Header pressure | Pressure transmitter, 0.25% class | 1 second | Main header, after treatment |
| Active power | Revenue-grade meter with current transformers | 1 second | Each compressor feeder, or the station switchboard |
| Air flow | Thermal mass or insertion flow meter | 1 second | Main header |
| Dew point | Capacitive dew-point sensor | 10 seconds | After the dryer |
| Ambient temperature and humidity | Combined sensor | 60 seconds | Compressor room intake |
| Controller data | Modbus TCP or OPC UA, read only | 1 second | Load and unload state, running hours, alarms, setpoints |
2. The baseline
Ninety days of your plant as it is, before anything is changed.
The baseline is the metered energy and flow of the station over 90 days before any fix, with planned shutdowns and grid outages excluded. It is expressed as specific energy, kWh per 1,000 m³ of air delivered, and as a regression of daily energy against the two things that drive it: a production proxy you choose (shifts, tonnes, line hours) and ambient temperature.
Fixes found during the baseline are logged and priced but not executed until the baseline closes, unless they threaten air availability, in which case they are executed and the baseline is adjusted and documented. The Baseline Report is signed by both parties and becomes an annex to the contract.
3. Verifying a saving
IPMVP Option B: all parameters measured at the station.
Each month, the baseline regression predicts what the station would have consumed under that month's production and ambient conditions. The verified saving is that adjusted baseline minus the metered energy. The report states the saving in kWh and riyals at the tariff in force, with the regression's uncertainty beside it; a saving smaller than its uncertainty is reported as zero.
The energy promise is a guaranteed specific energy. It is met when the twelve-month rolling average is at or below the figure in the contract, so that one hot month or one maintenance week does not decide the year.
4. The availability promise
Measured at the header, in minutes.
Availability is the share of the month in which header pressure stayed at or above the minimum you set, measured every second. Excluded by contract: planned shutdowns notified in advance, grid outages, and events caused by changes to the station made outside a HawaOS work order. Everything else counts, including failures of equipment that is not ours.
A missed month earns service credits on the next invoice and an Arcoma technician within the contracted response hours for every event; the credit scale is in the contract.
5. The monthly report
One document, two formats, no surprises.
What it contains
- Electricity consumed by the air system, metered, by station and by compressor
- Specific energy against baseline and target, with the twelve-month rolling average
- Availability: minutes below the set minimum, with causes
- Work orders raised, completed and verified, each with before-and-after data
- Verified savings in kWh and riyals, with uncertainty
- The open risks the model is watching, ranked
How it arrives
- A PDF in English and Arabic, on the fifth working day of the month
- The same figures as CSV, and by API for your energy-management system
- In the structure the Saudi Energy Efficiency Center's verification and ISO 50001 expect
- With the raw one-second data available to your energy manager on request
6. If we disagree
The contract names the referee before anyone needs one.
Either side can question a monthly figure within ten working days. A joint review of the data follows within ten more. If it does not settle the question, an independent energy auditor licensed by the Saudi Energy Efficiency Center decides, using the method in this page, and the party found wrong pays the auditor.
A worked month
A mid-size plant with a baseline of 118 kWh per 1,000 m³ runs in June at 96 kWh per 1,000 m³ after leak repair and a pressure-band change. June's adjusted baseline, corrected for a hotter month and a longer production run, predicts 236,000 kWh; the station used 192,000 kWh. Verified saving: 44,000 kWh, SAR 10,120 at 23 halalas, uncertainty ±6%. The twelve-month rolling average stands at 101, below the contracted 105, so the energy promise is met and the savings share applies.
Illustrative figures; every number in a real report traces to metered data.