ESOS (the Energy Savings Opportunity Scheme) is the UK’s mandatory energy assessment and energy-saving scheme for qualifying large organisations.
An organisation normally qualifies if it employs 250 or more people, or has both annual turnover above £44 million and a balance sheet total above £38 million. Corporate group rules can also bring smaller UK undertakings into scope.
Qualifying organisations must calculate their energy consumption across buildings, transport, industrial processes and other relevant activities. At least 95% of total energy consumption must be identified as significant energy consumption and covered through ESOS energy audits and/or an applicable deemed compliance route such as ISO 50001.
The assessment identifies practical opportunities to reduce energy use, including the expected savings, costs and payback of recommended measures. Where required, an approved ESOS Lead Assessor reviews the assessment and board-level directors must sign off the findings.
Compliance is reported through the government’s Manage your Energy Savings Opportunity Scheme service, known as MESOS.