Judgment of the Court (Grand Chamber) of 15 July 2021.#Federal Republic of Germany v Republic of Poland.#Appeal – Article 194(1) TFEU – Principle of energy solidarity – Directive 2009/73/EC – Internal market in natural gas – Article 36(1) – Decision of the European Commission on review of the exemption of the OPAL pipeline from the requirements on third-party access and tariff regulation following a request by the German regulatory authority – Action for annulment.#Case C-848/19 P.