ESOS Phase 3 Compliance
Energy Savings Opportunity Scheme for UK Large Undertakings
What is ESOS?
The Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment scheme for large undertakings in the UK. It requires qualifying organizations to conduct comprehensive energy audits every four years, identifying cost-effective energy efficiency opportunities.
UK Organizations Covered
Of Energy Use Must Be Audited
Maximum Penalty for Non-Compliance
Between Each Phase
ESOS Qualification Criteria
Your organization qualifies for ESOS if it meets ANY of these criteria on the qualification date (31 December 2022):
250+
Employees
UK staff or equivalent FTE
£44m+
Annual Turnover
And £38m+ balance sheet
Part of Group
Corporate Group
If group meets above criteria
Note: These are different thresholds from SECR(£36m turnover, £18m balance sheet). Many organizations qualify for both schemes.
ESOS Phase 3 Requirements
Energy Audit Requirements
- Audit at least 90% of total energy consumption
- Cover buildings, industrial processes, and transport
- Identify cost-effective energy saving opportunities
- Calculate payback periods and lifecycle costs
- Use 12 months of verifiable energy data
New Phase 3 Requirements
- Action Plan: Must create energy saving action plan
- Annual Reporting: Submit progress updates to Environment Agency
- Energy Intensity: Report energy use per unit of output
- Net Zero Plan: Include pathway to net zero emissions
- Public Disclosure: Some data will be published
ESOS Compliance Process
Determine Qualification
ImmediateCheck if your organization qualified on 31 December 2022. Consider corporate group structure and aggregation rules.
Appoint Lead Assessor
ASAPAppoint an approved ESOS Lead Assessor. Can be internal (if qualified) or external consultant. Register on ESOS portal.
Calculate Total Energy
March 2024Measure total energy consumption across all activities. Include electricity, gas, transport fuel, and other energy sources.
Conduct Energy Audits
April 2024Audit 90% of total energy use. Follow EN 16247 standards or use ISO 50001 certification as alternative compliance route.
Create Action Plan
May 2024Develop energy saving action plan with implementation timeline. Include net zero pathway and energy intensity metrics.
Board Sign-off
May 2024Obtain director-level sign-off on ESOS findings and action plan. Ensure board understands energy saving opportunities.
Submit Notification
5 June 2024Submit compliance notification via online portal to Environment Agency. Include all required documentation and declarations.
Alternative Compliance Routes
ISO 50001 Certification
Organizations with ISO 50001 covering all energy use are ESOS compliant. Must be certified by UKAS accredited body.
Learn about ISO standards →Display Energy Certificates
Valid DECs and accompanying advisory reports can cover buildings energy. Must be less than 10 years old.
Public buildings routeGreen Deal Assessments
Green Deal Assessments can cover domestic-type buildings. Must be conducted by qualified assessor.
Limited applicationESOS Costs & Penalties
Typical Compliance Costs
Non-Compliance Penalties
Warning: Publication of non-compliance causes reputational damage
Common Energy Saving Opportunities
Buildings (40% savings potential)
- • LED lighting upgrades
- • HVAC optimization
- • Building insulation
- • Smart building controls
- • Solar PV installation
Industrial (30% savings potential)
- • Variable speed drives
- • Compressed air optimization
- • Heat recovery systems
- • Process optimization
- • Motor efficiency upgrades
Transport (25% savings potential)
- • Fleet electrification
- • Route optimization
- • Driver training programs
- • Telematics systems
- • Modal shift opportunities
Average ROI: ESOS participants report average energy cost savings of 13% with typical payback under 2 years
ESOS Integration with Other Schemes
| Scheme | Overlap with ESOS | Key Difference |
|---|---|---|
| SECR | Energy & emissions data collection | SECR is annual reporting, ESOS is 4-yearly audits |
| SBTi | Emissions reduction planning | SBTi focuses on targets, ESOS on opportunities |
| CDP | Energy management disclosure | CDP is voluntary, ESOS is mandatory |
| ISO 50001 | Energy management system | ISO 50001 provides ESOS exemption |
ESOS Frequently Asked Questions
What happens if we miss the ESOS deadline?
Do we have to implement the energy saving opportunities?
How does ESOS relate to net zero targets?
Can we use ESOS data for SECR reporting?
What's changing for ESOS Phase 4?
Official ESOS & Energy Efficiency Resources
UK Government ESOS
Official Environment Agency ESOS compliance guidance
ESOS Phase 3 Official
Updated Phase 3 requirements and deadlines
Carbon Trust Energy
Independent energy efficiency auditing and certification
Energy Institute
Professional energy auditing standards and guidance
BSI Energy Management
ISO 50001 energy management system standards
EU Energy Efficiency
European Energy Efficiency Directive framework
IEA Energy Efficiency
International Energy Agency efficiency analysis
UK Energy Statistics
Department for Business energy consumption data
CIBSE Benchmarks
Building energy benchmarking standards TM46
Energy Saving Trust
Business energy efficiency advice and funding
UK Green Building Council
Sustainable building and net zero guidance
Climate Change Committee
Independent climate advice to UK government
ESOS Phase 3 Deadline Approaching
Ensure compliance by 5 June 2024 - Avoid penalties up to £50,000
Free ESOS Compliance Check
Verify your qualification status and get compliance roadmap