ESOS or ISO 50001?

by John Mulholland

Phase 3 of ESOS is already underway (6 December 2019 to 5 December 2023). Some companies are considering using an Energy Management Systems (EnMS) certified to ISO 50001 as a route to compliance. To take this route certification needs to be held on the compliance date of 5th December 2023. This may seem some time away but in EnMS terms it is closer than you think.

There are 5 steps to achieving certification to ISO 50001:

Step 1 EnMS Gap Assessment (2 weeks)

This is a sensible idea to assess the current energy management practices against the requirements of ISO 50001.

Step 2 EnMS Building (6 to 8 weeks)

This is where a tailor-made EnMS is built and geared to your organisation.

Step 3 EnMS Population (5 to 10 weeks)

Here the EnMS is populated with data to demonstrate current practice and compliance. Any gaps identified in Step 1 should be addressed at this stage.

Step 4 EnMS Operation (26 to 52 weeks)

This is where the EnMS is run for 6 to 12 months with internal audits and at least one management review.

Step 5 EnMS Certification (10 weeks)

Here an accredited certification body will conduct Stages 1 and 2 certification. The two stages are usually separated by six weeks. Stage 1 is an assessment by the certification body to see if the EnMS is in a state of readiness. If Stage 2 is successful, certification is usually issued in about 4 weeks. Certification lasts for three years, subject to surveillance audits.

So if a company embarked on this process in January of a given year the timeline would be approximately:

Stage Completion Date
Step 1 EnMS Gap Analysis End of January Year 1
Step 2 EnMS Building End of March Year 1
Step 3 EnMS Population End of June Year 1
Step 4 EnMS Operation (assume 9 months) End of March Year 2
Step 5 Certification End of June Year 2

So the whole process typically takes 18 months.

Of course some originations will take longer or may complete the process faster depending on how well organised they are and current energy management practices.

ISO 50001:2018 was published in August 2018. For organisations holding ISO 50001:2011, they must transition to the new version of the Standard (ISO 50001:2018) by August 2021. This means that in Phase 3 of ESOS, any company using ISO 50001 as a route to compliance on 5 December 2023, will have to hold certification to ISO 50001:2018.