Judgment of the General Court (Seventh Chamber, Extended Composition) of 21 December 2022.#Landwärme GmbH v European Commission.#State aid – Biogas market – Tax exemptions compensating for additional production costs – Decisions not to raise objections – Action for annulment – Interest in bringing proceedings – Admissibility – Failure to initiate the formal investigation procedure – Serious difficulties – Article 108(2) and (3) TFEU – Article 4(3) and (4) of Regulation (EU) 2015/1589 – Guidelines on State aid for environmental protection and energy 2014-2020 – Cumulation of aid – Aid granted by several Member States – Imported biogas – Principle of non-discrimination – Article 110 TFEU.#Case T-626/20.