In the European electricity sector, the delegation of rule-making has literally reached the next level. Socalled ‘methodologies’, legally binding rules developed between private electricity companies and specialized regulatory agencies, constitute a vast and growing body of ‘quaternary law’.

The methodologies and their unique features raise numerous interesting questions for scholars of EU law, but they remain severely underresearched. This is regrettable, since the methodologies illustrate another pressing issue related to the delegation of rule-making: the fuzzy legal boundaries to delegation. These follow from the European Court of Justice’s (ECJ’s) non-delegation, or Meroni doctrine, which however seems to be subject to a creeping maceration. As the methodologies show, the resulting legal uncertainty encourages ever-bolder models of delegation, raising grave constitutional concerns.

At the same time, the methodologies illustrate a need for delegated rule-making in technical sectors, such as electricity. The argument of this article is that the ECJ should therefore revise the Meroni doctrine to restore legal certainty with respect to delegation, while also respecting the requirements of regulatory reality. This article discusses possible approaches and proposes a starting point for a ‘Meroni doctrine 2.0ʹ.