Overview of previous schemes

ECO1, ECO2 and ECO2t

The first phase of the Energy Company Obligation (ECO), known as ECO1, ran from January 2013 to March 2015. This placed obligations on larger energy suppliers to deliver energy efficiency measures to domestic premises in Great Britain.

There were three main obligations under ECO1 which energy companies were required to meet. The obligations were the Carbon Emissions Reduction Obligation (CERO), the Carbon Saving Community Obligation (CSCO) and the Home Heating Cost Reduction Obligation (HHCRO). CSCO also had a sub-obligation focused on rural areas (the CSCO rural sub-obligation). Under ECO1 suppliers were required to achieve an overall target of 12.4 Mt CO2 for CERO, 6 Mt CO2 for CSCO and £3.7billion for HHCRO. Suppliers achieved 18.33 Mt CO2 under CERO, 9.87 Mt CO2 under CSCO, including 1.79 Mt CO2 under the rural sub-obligation, and £5.16billion under HHCRO. 

The next obligation period, known as ECO2, launched on 1 April 2015 and ended on 31 March 2017. Suppliers were required to achieve the following cost and carbon savings - 19.7 Mt CO2 under CERO, 6 Mt CO2 under CSCO and £6.46 billion under HHCRO.

The government extended this policy until 30 September 2018 with a new period termed ECO2t. You can view a summary of the changes made on the government website. Energy suppliers were required to achieve 7.3 Mt CO2 for CERO and £2.76 billion for HHCRO. The CSCO target had to be achieved by 1 April 2017, while the CERO and HHCRO targets had to be achieved before 1 October 2018.


The Carbon Emissions Reduction Target (CERT) ran between 1 April 2008 and 31 December 2012. CERT required larger gas and electricity suppliers to achieve targets for reducing carbon emissions from domestic premises in Britain.

The Gas and Electricity (Carbon Emissions Reduction) Order 2008 and subsequent amendments set out the levels of savings required and the way in which these were to be achieved.

Energy suppliers were required to achieve an overall target of 293 million lifetime tonnes of carbon dioxide (Mt CO2) by 31 December 2012. Energy suppliers achieved 296.9 Mt CO2.


The Community Energy Saving Programme (CESP) ran from 1 October 2009 to 31 December 2012. CESP was created as part of the government's Home Energy Saving Programme.

The Department of Energy and Climate Change (DECC) set an overall carbon emissions reduction target of 19.25 Mt CO2. This was to be met by requiring gas and electricity suppliers and electricity generators to deliver energy saving measures to domestic consumers in specific low income areas of Britain. This obligation was placed on all licensed gas and electricity suppliers that had at least 50,000 domestic customers and all licensed electricity generators that had generated on average 10 TWh/yr or more in a specified three-year period.

CESP was designed to promote a 'whole house' approach and to treat as many properties as possible in defined geographical areas selected using the Income Domain of the Indices of Multiple Deprivation (IMD) in England, Scotland and Wales.

Energy companies were required to achieve an overall target of 19.25 Mt CO2 saving by 31 December 2012. Energy companies achieved a saving 16.31 Mt CO2, almost 85% of the overall target.


The Energy Efficiency Commitment (EEC) scheme ran from 2002 to 2005 and the second scheme (EEC2) ran from 2005 to 2008. The forerunner of EEC was the Energy Efficiency Standards of Performance (EESoP), which ran from 1994 to 2002. EESoP1, EESoP2 and EESoP3 ran respectively from 1994 to 1998, 1998 to 2000 and 2000 to 2002.

EESoP was jointly developed and managed by us (initially Offer) and the Energy Saving Trust.

EEC, while differing in several important ways, built on the success and basic methodology of EESoP.

Both EEC and EESoP had an emphasis on disadvantaged customers. The majority of measures in EESoP1 and around two thirds of supplier expenditure in EESoP2 and EESoP3 focused on disadvantaged customers. Similarly, EEC2 had a requirement for at least 50 per cent of the target to be met in relation to Priority Group consumers, defined as those in receipt of certain income-related benefits and tax credits.

Publications and updates

  • Published: 4th Dec 2012
  • Factsheets
  • 1 Associated documents
Updated report on CERT supplier activity - December 2012

  • Published: 27th Nov 2012
  • Closed: 21st Dec 2012
  • Consultations and responses
  • 1 Associated documents
This consultation seeks views on the proposed methodologies to be used by electricity and gas suppliers to calculate the number of domestic customers and amount of electricity and gas supplied to set obligations for Phases Two and Three of ECO.

  • Published: 26th Nov 2012
  • Other
  • 1 Associated documents
This is the CERT Savings spreadsheet V15 so that Obligated energy suppliers can report their interim and final reports.

  • Published: 23rd Nov 2012
  • Closed: 25th Jan 2013
  • Consultations and responses
  • 1 Associated documents
This consultation seeks views on our draft guidance document Energy Companies Obligation (ECO) 2012-2015 : Guidance for Suppliers.

  • Published: 21st Nov 2012
  • Decisions
  • 1 Associated documents
This letter outlines our decision on the Social Housing Provider Super Priority Group percentage proposal.

  • Published: 29th Oct 2012
  • Agendas, minutes and presentations
  • 1 Associated documents
See our open letter informing CERT obligated energy companies of our 'minded to decision' to accept an agreed super priority group percentage for eligible super priority group installations in social housing properties.

  • Published: 24th Sep 2012
  • Factsheets
  • 1 Associated documents
See the Community Energy Saving Programme (CESP) Update 5 - September 2012.

  • Published: 24th Sep 2012
  • Factsheets
  • 1 Associated documents
See the updated Carbon Emission Reduction Target update 17 - September 2012.

  • Published: 21st Sep 2012
  • Open letters and correspondence
  • 1 Associated documents
This open letter sets out our approach to Enforcement of the CERT and CESP schemes.

  • Published: 17th Sep 2012
  • Other
  • 1 Associated documents
See the Community Energy Saving Programme (CESP) carbon emissions reduction scores for CESP related measures.