Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.


In 2021 the ASA and CAP will undertake a Climate Change and the Environment project taking stock of the rules regulating environmental claims.  This project consists of three concurrent strands:

  • Proactive regulation: proactively looking at environmental claims in several priority areas with a view to updating our position on emerging and existing themes and taking action against advertisers who use green claims in a way that is likely to mislead or cause harm. 
  • Standards fit for the 2020s: taking stock of how effective our rules and guidance are in governing environmental claims. 
  • Knowledge, education and communication: updating our existing resources to make them easily accessible, and creating new training materials and other educational resources to improve industry’s understanding and overall compliance with our rules on misleading and harmful environmental claims.

Please note that this advice article, and others, are likely to be updated in due course.

Claims about the output of a renewable electricity producing site should be demonstrably true.

If the ad makes claims about the future output of a specific site, such as a wind farm, the predicted output should be calculated using site specific data. If a claim is based on an estimated output but not on historical data (for example for a proposed site) that fact should be made clear to consumers. That can be done by stating “estimated output” or by making the output claim conditional, for example “could produce up to …”. Definitive claims about the output of sites that are not based on site-specific data are likely to be problematic (Druim Ba Sustainable Energy Ltd, 31 October 2012).

Marketers may describe the output of a given site by stating the number of homes that could be supplied by that site but should not imply that the electricity is delivered directly to those homes. When calculating the number, the Copy Advice team recommends using an up-to-date average electricity consumption figure published by a relevant authoritative body, such as that recommended by Ofgem of 3.3 MWh.

Comparisons, such as comparing the amount of emissions with those produced by a car, are likely to be acceptable if the comparison makes clear the specific model of car used (RWE Npower t/a Npower Renewables, 21 February 2007).

Marketers of energy from renewable sources often want to make claims about the beneficial effect to the environment, usually expressed as a reduction of carbon dioxide emissions, compared with electricity from conventional sources. If they make conditional claims such as "It is estimated that the Brightenber Hill wind farm could save more than 7,741 tonnes of CO2 each year*", marketers should be able to show that that estimate has been based on the relevant capacity factor and that figures used are representative of the current UK electricity-generating mix (Energiekontor UK Ltd, 30 May 2012).

See other entries on Environmental claims: General and Environmental claims: Marketing of electricity from renewable sources General


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