What is idle energy consumption in a factory?

It is the energy used when nothing is being produced: overnight, at weekends, during breaks or with machines switched on but not working. It is also called base load.

How can I measure idle consumption without installing lots of equipment?

Start with the half-hourly or 15-minute load profile from your supplier or network operator, or a power analyser on the main switchboard. If the base load is high, add sub-meters per line or machine to locate the source.

Which measure usually delivers results fastest?

Switching off or isolating what is not needed outside production, especially compressed air, and fixing leaks. These are low-cost measures you can verify within a few weeks.

Do I need ISO 50001 to reduce idle consumption?

No. ISO 50001 is a useful framework for managing energy systematically, but you can measure and reduce base load without being certified.

Energy efficiency

Idle energy consumption: find what your factory uses when idle

Published 19 July 20265 min readLeer en español

Short answer

Idle consumption is the energy a factory uses when it is not producing: nights, weekends, breaks and machines on standby. You find it by logging power every 15 minutes and comparing it with the production schedule. It is usually cut first with procedures, schedules and automatic shutdown, before any capital investment.

Key points

Idle consumption, or base load, is the power that remains when there is no production.
Compressed air, extraction, pumps, heating and cooling, and machines on standby are the usual suspects.
A 15-minute power profile set against the production schedule reveals the problem within a few weeks.
The first fixes are usually cheap: procedures, schedules, interlocks and a leak programme.
Savings are verified by comparing periods with equivalent production, not just bills.

Many factories keep drawing a significant share of their power when they are producing nothing. This idle consumption is not seen as a problem because nobody sees it: it happens overnight, at weekends or while machines wait. The good news is that it can be measured with simple tools, and the first fixes usually cost little.

What is idle consumption or base load?

It is the power the site demands when there is no production. Part of it is unavoidable: security, servers, product refrigeration, emergency lighting. Another part is simply habit: equipment nobody switches off because “it has always been on”.

The aim is not to reach zero, but to separate what is needed from what is avoidable, and cut the latter.

Which equipment usually causes idle consumption?

Equipment	Why it consumes without producing	What to check
Air compressors	Leaks in the network; the compressor loads and unloads to hold pressure	Load cycles outside shifts, pressure setpoint
Extraction and ventilation	Runs on a fixed timetable, not on activity	Schedules, interlock with machines
Pumps	Continuous recirculation, circuits with no isolating valve	Real need outside production
Conveyors	Keep running with no load	Automatic stop when no product is present
Heating and cooling	Same setpoints with an empty building	Time programming, weekend setpoints
Lighting	On in areas with no activity	Zoning, sensors, schedules
Machines on standby	Hydraulics, heaters, servos and panels left energised	Genuine standby mode, shutdown sequence

Compressed air deserves special attention. With the plant stopped, a compressor that keeps starting every few minutes almost always means leaks in the network.

How do I measure idle consumption?

Start with the total

Many electricity suppliers and network operators can provide the interval load profile for your supply point. If not, a power analyser on the main switchboard records the same thing. That alone shows how much the plant draws at 3 a.m. or on a Sunday.

Then sub-meter

If the base load is high, you need to know where it sits. To find out:

Fit energy meters on the main outgoing circuits (per line or per service: air, cooling, lighting).
On specific machines, use split-core current transformers connected to a meter or a PLC.
Log the data locally using open protocols such as Modbus or MQTT, so you do not depend on a single vendor or on internet access.

Any work inside electrical panels must be carried out and certified by a licensed electrician.

What simple method works to detect it?

Log power (kW) at 15-minute intervals for at least two or three weeks.
Mark the production schedule on the same chart: shifts, breaks, weekends and holidays.
Look at the troughs. Minimum power overnight and at weekends is your base load.
Compare base load with power during production. If the base is a large fraction of the peak, there is room to act.
Look at the transitions. How long does power take to drop after the shift ends? How early does it rise before the shift starts? Very early start-ups are a common finding.
Repeat per line or service using sub-metering to assign each kW to a piece of equipment.

A spreadsheet is enough for this analysis. You do not need dedicated software for the first diagnosis.

How much can idle consumption cost? An example

The figures below are illustrative, not data from any particular plant.

Take a factory running two 8-hour shifts, 5 days a week, 50 weeks a year:

Production hours: 16 h × 5 days × 50 weeks = 4,000 h/year
Non-production hours: 8,760 − 4,000 = 4,760 h/year

If the base load outside production is 35 kW and you estimate 20 kW of it is avoidable:

Avoidable energy: 20 kW × 4,760 h = 95,200 kWh/year
At an example price of €0.15/kWh: 95,200 × 0.15 = €14,280/year

Run the same sum with your own values. The order of magnitude is usually enough to decide whether it is worth investigating.

Which measures reduce idle consumption?

Rank them from lowest to highest cost:

Procedures. A shutdown checklist at the end of each shift and on Friday, with a named owner.
Schedules. Programme extraction, heating, cooling and lighting to the actual production calendar.
Isolate compressed air. Close section valves and stop compressors outside shifts where the process allows.
Leak programme. Periodic detection (for example, with ultrasound), tagging and repair with follow-up.
Interlocks and automatic shutdown via PLC. Stop conveyors, extraction or pumps when the associated machine has been idle for a defined time.
Investment. Variable speed drives, variable-speed compressors, equipment replacement. Only after measuring, and with the saving calculated. On drives, see when variable speed drives pay off on pumps and fans.

How do I verify the savings are real?

Comparing two months of bills is not enough: production, weather and prices all change.

Compare periods with equivalent production, or normalise consumption per unit produced (kWh per part, per tonne or per machine hour).
Measure base load before and after overnight and at weekends, where production does not interfere.
Account for temperature if there is heating, air conditioning or process cooling.
Keep measuring. Leaks come back and procedures get forgotten; continuous logging catches both.

If you want a broader framework, ISO 50001 describes an energy management system built on measuring, setting objectives and reviewing. It is not essential to get started, but it brings order to the work over the long term.

Quick checklist

At least two weeks of 15-minute load profile
Production schedule overlaid
Night and weekend base load calculated
Sub-metering on the heaviest services
Low-cost measures in place, each with an owner
Normalised before/after comparison

How we approach it at Kinetifab

We measure first: we fit sub-metering with open protocols and local logging, analyse the base load with you and propose measures in order of cost, with the scope fixed in writing. You can read more under energy and industrial automation, or get in touch. If most of the base load comes from older machines, machine retrofit: modernise or replace may also help.