Internal audit ISO 50001

The internal audit is a requirement under clause 9.2 of ISO 50001:2018 . You periodically check whether your own energy management system works as intended. Think of it as a dress rehearsal before the external auditor from an accredited certification body  arrives. Organisations that take the internal audit seriously have far fewer surprises at the certification audit.

On this page

What does clause 9.2 require?

Clause 9.2 of ISO 50001 imposes four obligations:

1. Audit programme: You set up a programme with the planned intervals, scope, methods and reporting requirements. Annually is the usual frequency, but the standard does not prescribe a fixed frequency.
2. Independence: Auditors do not assess their own work. The energy manager does not audit the part of the system they set up themselves.
3. Reporting: You record findings and report the results to the relevant managers.
4. Follow-up: Shortcomings receive a corrective action. You check whether the action worked.

The standard sets no minimum number of audit hours and no specific report format. That leaves room for an approach that suits the size of your organisation.

Energy-specific audit points

With ISO 50001, alongside the standard management system requirements, you also check the energy-specific elements from chapter 8. This is the part that makes the internal audit for ISO 50001 different from that for ISO 9001 or ISO 14001.

Energy review and SEU register

• Are the significant energy aspects (SEUs) still current? Have new large users been added or removed?
• Is the energy review documented and recently updated?
• Are the criteria for designating SEUs correct? Are they recorded in a traceable way?
• Does the SEU register cover at least 70-80% of total energy use?

Example: A manufacturing company installs a new press on its production line halfway through the year. That press uses 15% of the electricity. The internal auditor checks whether the press was assessed as a potential SEU and, if necessary, included in the register.

Energy baseline

• Has the energy baseline been set and documented?
• Is the baseline normalised for variables such as production volume, occupancy rate or outside temperature?
• Have there been events (new machines, building changes, production changes) that require the baseline to be reassessed?

Example: A company does not adjust its baseline after production has grown by 30%. The internal auditor notices this and raises it as a finding: the baseline no longer reflects the current situation.

EnPIs: measurement and reporting

• Are the energy performance indicators (EnPIs) defined and relevant to the SEUs?
• Are EnPIs measured and reported at the agreed interval (monthly, quarterly)?
• Does the trend show an improvement compared with the baseline?
• Are measuring instruments calibrated? Are there calibration records?

Action plans and progress

• Is there an action plan for each SEU with a responsible person, deadline and budget?
• Have quick wins been carried out? Is there demonstrable progress?
• Are planned measures on track, or are there delays with valid reasons?
• Have the results of implemented measures been measured and compared with expectations?

Competence and awareness

• Are employees who work with SEUs demonstrably trained?
• Do operators know what the energy objectives are and what role they play in them?
• Is there a competence matrix showing who has had which training?

Operational control

• Are there work instructions for energy-efficient operation of SEUs?
• Are these instructions followed? Are there deviations?
• Are procurement criteria for energy and equipment recorded?

Who carries out the internal audit?

The main rule is independence: auditors do not assess their own work.

Small company (1-50 employees): Someone from another department audits the energy function. Did the managing director set up the system? Then have an external auditor join for one day before the internal audit. Cost: €1,000-€2,500.

Medium-sized company (50-250 employees): The facility manager audits the production SEUs, and the production manager audits the HVAC. Or train one employee as an internal auditor (a day course for ISO internal auditors is sufficient).

Large company (250+ employees): Own pool of internal auditors who rotate across departments and locations. Often already available if you also have ISO 9001 or ISO 14001.

Combined with ISO 14001: If you already have internal auditors for ISO 14001, they can cover the energy-specific parts after brief training (half a day). This saves time and cost.

Setting up an audit programme

An audit programme records which parts are audited when, by whom and using which method.

Frequency: ISO 50001 does not prescribe a fixed frequency, but full annual coverage is the common practice. SEUs and processes with earlier findings need attention more often.

Risk-based planning: Spend more time on:

• Processes that are SEUs (large impact if they deviate)
• Parts with deviations in previous audits
• Recently changed processes or installations

Time investment: Plan the internal audit at least 6-8 weeks before the external certification audit. That gives you time to properly resolve findings.

Internal audit checklist ISO 50001

Use this checklist as the basis for your own audit programme. Add organisation-specific points for attention.

Context and scope (clause 4)

• Is the scope of the EnMS still current (locations, processes, energy types)?
• Have the interests of relevant parties been updated?

Leadership and energy policy (clause 5)

• Is the energy policy signed and current?
• Are roles and responsibilities documented and known?
• Has management made resources available?

Energy review and SEUs (clause 8.4)

• Has the energy review been updated (at least annually or after major changes)?
• Have SEUs been determined on the basis of documented criteria?
• Does the SEU register cover ≥70% of total use?
• Is SEU data (use, priority) current?

Energy baseline (clause 8.5)

• Has the baseline been set and documented?
• Has it been corrected for relevant variables?
• Has the baseline been reassessed after major changes?

EnPIs (clause 8.6)

• Are EnPIs defined per SEU and at organisation level?
• Is at least 3 months of measurement data available?
• Are EnPIs reported at the agreed interval?
• Are measuring instruments calibrated (records present)?

Action plans (clause 8.3 and 6.2)

• Is there an action plan per SEU with a responsible person and deadline?
• Have quick wins been carried out?
• Is there progress on medium-term measures?
• Have the results of completed measures been measured?

Support (clause 7)

• Is there a competence matrix for roles with SEU impact?
• Have relevant employees been trained?
• Are employees aware of the energy objectives and their own contribution?
• Is documentation findable and current?

Management review (clause 9.3)

• Has the latest management review been held?
• Are minutes available with decisions and actions?
• Have action points from the previous review been followed up?

Corrective actions (clause 10.2)

• Have deviations been documented?
• Has the cause been analysed?
• Have corrective actions been taken and checked for effect?

Common mistakes

Planning too late. Planning the internal audit just before the certification audit leaves no time to resolve findings. Plan at least 6-8 weeks in advance.

Skipping the energy-specific elements. Auditors with a background in ISO 9001 or 14001 sometimes forget the energy-specific elements: baseline, EnPI trends, SEU criteria. Use the checklist above as a memory aid.

Reporting too few findings. A report with no findings raises suspicion. Every system has points for improvement. Actively look for them.

Not following up findings. You record a deviation but do not check whether the measure worked. Clause 10.2 requires verification of the corrective action.

The auditor audits their own work. Small organisations run into this. Arrange for someone else to audit this part, even if that is an external person.

More information

• ISO 50001 audit process: the external certification audit in detail
• Energy performance indicators (EnPIs): how EnPIs work and what you measure
• Energy baseline: setting and normalising the reference point
• Determining SEUs: mapping significant energy aspects
• ISO 50001 step-by-step plan: the full route to certification
• Requirements of ISO 50001: all chapters of the standard explained

Sources

• ISO 50001:2018 : official standard, including clause 9.2
• NEN: ISO 50001 : Dutch publication
• Dutch Accreditation Council (RvA) : accredited certification bodies