A scheme established by powers under the Energy Act 2013 to support independent renewable generators by providing eligible generators with a guaranteed "backstop" route-to-market at a specified discount to the market price under a backstop PPA. The OLR mechanism was introduced as part of Electricity Market Reform (EMR). For more information, see Practice note, Contracts for Difference (CFDs) for low carbon generation: overview: Offtaker of last resort or backstop PPA.

For more information on PPAs generally, see Practice note, Power purchase agreement: key issues for drafting, reviewing and negotiating.