Key facts of the case:

Reference for a preliminary ruling — Directive 2001/42/EC — Environmental impact assessment — Development consent for the installation of wind turbines — Article 2(a) — Concept of ‘plans and programmes’ — Conditions for granting consent laid down by an order and a circular — Article 3(2)(a) — National instruments setting the framework for future development consent of projects — Absence of environmental assessment — Maintenance of the effects of national instruments, and consents granted on the basis of those instruments, after those instruments have been declared not to comply with EU law — Conditions.

Outcome of the case:

On those grounds, the Court (Grand Chamber) hereby rules:

1. Article 2(a) of Directive 2001/42/EC of the European Parliament and of the Council of 27 June 2001 on the assessment of the effects of certain plans and programmes on the environment must be interpreted as meaning that the concept of ‘plans and programmes’ covers an order and circular, adopted by the government of a federated entity of a Member State, both of which contain various provisions concerning the installation and operation of wind turbines.
2. Article 3(2)(a) of Directive 2001/42 must be interpreted as meaning that an order and a circular, both of which contain various provisions concerning the installation and operation of wind turbines, including measures on shadow flicker, safety, and noise level standards, constitute plans and programmes that must be subject to an environmental assessment in accordance with that provision.
3. Where it appears that an environmental assessment within the meaning of Directive 2001/42 should have been carried out prior to the adoption of the order and circular on the basis of which a consent, which is contested before a national court, was granted for the installation and operation of wind turbines with the result that those instruments and that consent do not comply with EU law, that court may maintain the effects of those instruments and that consent only if the national law permits it to do so in the proceedings before it and if the annulment of that consent would be likely to have significant implications for the electricity supply of the whole of the Member State concerned, and only for the period of time strictly necessary to remedy that illegality. It is for the referring court, if necessary, to carry out that assessment in the case in the main proceedings.