Sardinia, the renewable energy stakes return to the Consulta

A new episode in the regulatory affair concerning the tangled issue of renewable energy development in Sardinia. After ruling 184 of 16 December 2025, which had declared several provisions of the Sardinian law on eligible areas, Law 20/2024, unconstitutional, it is now back before the Constitutional Court. The focus is on the constitutional legitimacy of the law's annexes, which materially identify unsuitable areas. In particular, the "annexes A, B, C, D, E and paragraphs 9 and 11 of Article 1 of the law", as written in the agenda of the public hearing of the Constitutional Court on 5 May last, which concerned the questions of constitutional legitimacy referred by the Sardinian Regional Administrative Court and the Lazio Regional Administrative Court with reference to the complaints made by companies operating in the renewable energy sector such as Maple Tree Solar, Rwe Renewables Italia, Sorgenia Renewables, Green Sole Renewables Italia 1, Ef Agri Società Agricola, and Edison Rinnovabili.

Carlo Comandè, from the firm Cdra, is one of the lawyers following the proceedings: the lawyer had already followed several appeals, including those that led to the rewriting of the dm Aree Idonee last year. "The annexes to the Sardinian law had not been challenged by the presidency of the Council of Ministers in the proceedings that led to its partial declaration of unconstitutionality by the Constitutional Court in December 2025. Instead, they have now been challenged by several operators. The hearing on 5 May focused precisely on the constitutionality of the technical rules, contained in the annexes, which establish which areas are eligible. Rules that currently establish 96 per cent of the Sardinian territory as unsuitable areas, with the substantial effect that in almost all of Sardinia the simplification and acceleration rules of EU matrix do not apply,' Comandè explains.

In the meantime, the Constitutional Court has entered into the merits of the various appeals between the Region of Sardinia and the Ministry of the Environment. It emphasised, with sentence number 88 of 2026 deposited on 25 May, that the state administrative authority (the ministry) must apply the regional regulations in force (specifically 20/2024) since only the Constitutional Court can declare their illegitimacy. The Court upheld the conflicts promoted by the Region of Sardinia for the annulment of several Mase decrees containing environmental impact assessments concerning the construction of agri-voltaic plants in the provinces of Oristano and Sassari, which were adopted by excluding the comparison with the contents of Law 20/2024 precisely, concerning the identification of areas suitable and unsuitable for the installation of renewable energy plants. According to the Ministry, the Sardinian regional law should have been considered illegitimate and, therefore, not applicable, because it would have severely limited the spread of renewable plants in the Region, jeopardising the achievement of the European objectives on renewables.

"The Ministry adopted favourable environmental impact decrees disapplying the Sardinian law that it considered unconstitutional. The Region of Sardinia appealed for a conflict of attribution and now the Constitutional Court reaffirms that it is the only one that can declare a law unconstitutional, agreeing with the Region of Sardinia, in the sense of deeming illegitimate the Ministry's disapplication of the law. However, in essence, the impact of this pronouncement is very limited since in December 2025 the same Court declared Sardinian law 20/2024, disapplied by Mase, partially unconstitutional', consequently, Comandè again emphasises, 'At the moment, there are no practical consequences for operators or effects on similar situations concerning other Regions.