Article 27 1.

National energy regulatory authorities shall apply the energy efficiency first principle, in accordance with Article 3 of this Directive, in carrying out the regulatory tasks provided for in Directives 2009/73/EC and (EU) 2019/944 regarding their decisions on the operation of the gas and electricity infrastructure, including their decisions on network tariffs. In addition to the energy efficiency first principle, national energy regulatory authorities may take into account cost efficiency, system efficiency and security of supply, and market integration, while safeguarding the Union’s climate targets and sustainability, as set out in Article 18 of Regulation (EU) 2019/943 and in Article 13 of Regulation (EC) No 715/2009.