Measure
Build a defensible picture of where energy is being used and where data quality needs improvement.
ESOS
ESOS Phase 4 support led by an experienced ESOS Lead Assessor.
PB Energy can help qualifying organisations turn the Energy Savings Opportunity Scheme from a compliance exercise into a structured review of where energy, carbon and cost savings can actually be achieved.
Who qualifies for Phase 4?
ESOS applies to large UK undertakings and qualifying corporate groups. For Phase 4, an undertaking is large if on 31 December 2026 it either employs 250 or more people, or has annual turnover above £44 million and an annual balance-sheet total above £38 million. The Phase 4 notification-of-compliance deadline is 5 December 2027.
What ESOS looks at
An ESOS assessment reviews energy used by buildings, industrial processes and transport. The objective is to identify tailored, cost-effective energy-saving opportunities rather than simply produce a compliance statement.
How PB Energy can support
- Qualification and organisational-boundary review
- Total energy-consumption and significant-energy-consumption analysis
- Site and process energy audits
- Energy-saving opportunity identification and quantification
- Lead Assessor review and sign-off support
- Evidence-pack and reporting support
- Action-plan development and progress-review support
- Integration of opportunities into wider net zero and capital plans
Phase 4 has a stronger focus on action
Current Phase 4 rules require more information on energy savings achieved, progress against action-plan commitments and reasons where proposed measures have not been implemented. That makes it increasingly useful to link the compliance process to an internal programme of delivery and measurement.
ISO 50001 and ESOS
ISO 50001 can provide an alternative compliance route where the certified energy-management system covers the relevant energy consumption. The appropriate route depends on the organisation’s existing certification and ESOS boundary.
Beyond compliance
Use the ESOS work to create an investable opportunity register.
A strong assessment can distinguish operational changes, low-cost measures and capital projects, then rank them by energy impact, cost, practicality and timing.
Prioritise
Separate quick wins from projects that need technical development, funding or planned asset replacement.
Deliver
Connect recommendations into solar, storage, controls, operational change and ongoing performance review.
Optional decarbonisation assessment
Phase 4 guidance allows participants to voluntarily include net-zero considerations using PAS 51215-1:2025 and PAS 51215-2:2025. PB Energy can help integrate those considerations into a wider reduction roadmap where appropriate.