FAQ: What is ESOS and how do you comply with it?

With 1  year left to complete your Energy Savings Opportunity Scheme (ESOS) requirements, we look at the most frequent questions our customers have had, and clear the confusion so you’re in the best position for compliance.

What is ESOS?


The Energy Savings Opportunity Scheme (ESOS) is a compliance scheme that started in 2015, with no foreseeable end date. It is the UK’s implementation of the EU Energy Efficiency Directive and has been confirmed to stay in place post-Brexit.

The aim of ESOS is to assess your energy consumption, identifying reasonable opportunities to reduce your energy use and improve resource efficiency across your operations. For most, this is in electricity and gas use, but could also include other fuels such as petrol, diesel, coal, etc.

2. Who qualifies for ESOS Phase 3?

In short, a company meets the criteria if you either have:

    • more than 250 employees, or
    • a turnover of more than £44,845,000, AND a balance sheet of more than £38,566,700.

If a company within a group structure meets the criteria, then the entire group must comply. The qualification criteria can be a little complex so if you are not sure, please get in touch with us and we can investigate for you.

3. What is the ESOS Phase 3 deadline? 

There is only one deadline for ESOS Phase 3 which, has been extended to the 5th June 2024. This is the deadline by which your submission to the Environment Agency must have been complete.

4. What does complying with ESOS entail? 

ESOS requires 5 things:

  • Calculate your total energy consumption – this requires the collection of data from all areas of consumption across complying businesses and calculation/conversion to kWh.
  • Identify and audit areas of significant energy consumption – 95% of energy consumption needs to have been audited by a sampled approach. This is an increase from 90% on previous phases so expected to see more audits going forwards.
  • Complete the compliance work – a Lead Assessor must be appointed to oversee the work. They will ensure that all the compliance requirements are met, hold a sign-off presentation with your responsible director and ensure the Environment Agency is notified on time
  • Notify the Environment Agency – a submission to the EA must be completed on or ahead of the deadline to complete your compliance
  • Keep records – we produce an Evidence Pack detailed everything we have done and the methodology used.

5. What would happen if you don’t comply with ESOS in time, or submit your notice late? 

For Phase 3, it’s been made clear that there won’t be any room for delays in submissions. Any compliance completed after the deadline will likely receive enforcement action with penalties. Penalties are a base mount plus an additional amount added per day until compliance is complete.

6. How does ESOS fit in with Net Zero? 

For many organisations who haven’t begun their journey towards Net Zero yet, ESOS is a great way to get started.

Energy can be full of quick wins to reduce consumption and therefore carbon emissions which is why we encourage ESOS as being a driving force rather than a tick-box exercise. Once done, we can support you to look at the wider areas of your emissions including purchases, supply chain, products, etc. and build those into a Net Zero strategy.

7. What to look for in an ESOS consultant and lead assessor?

We believe in using ESOS not only as a compliance exercise but also as a big step in taking action to manage your energy consumption.

That’s why we provide detailed reports for each site/fleet audit we complete with an in-depth assessment of the data available, well-costed opportunities to reduce energy and carbon, an assessment of renewable opportunities available, and a summary of what offsetting would be required to make the site’s operations Net Zero.

In 2019, as part of ESOS Phase 2, we audited 1.2% of the UK’s total energy use and completed over 400 audits. With multiple ESOS Lead Assessors in-house, experienced in conducting ESOS across all sectors, we’re well-positioned to support you and excited to join you on the journey.

Any other questions we didn’t get around to?

Get in touch at gonetzero@energise.com and one of our team will walk you through the next steps.

Written By    Adam Wright

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