As is well known, for several months now the players in the energy and infrastructure market have been eagerly awaiting the entry into force of the so-called "Energy Decree" given the significant potential effects deriving from future regulation on virtual saturation of electrical networks and Data Center development (for further information on these topics, see our previous articles:Virtual network saturation andInvesting in Data Centers).
In recent weeks, a new draft of the aforementioned decree has circulated which, if on one hand it did not seem to bring substantial changes on the saturation and DC front, on the other hand it has been enriched, introducing a substantial reorganization of the so-called "suitable areas" for the installation of renewable plants.
From the "Energy Decree" the measures in question have now formally migrated to Decree no. 175 of 21 November 2025 also known as "Transition 5.0 Decree" and originally intended, precisely, to regulate only the tax credits referred to in the Transition 5.0 Plan (the "Decree").
The Decree, published in the Official Gazette on November 21 last, introduces multiple amendments to Legislative Decree no. 190/2024 (also known as "TU Renewables") substantially going to abrogate the rules of the game as we currently know them and, in detail:
the discipline of suitable areas ope legis referred to in art. 20, co. 8 of Legislative Decree 199/2021 (and, consequently, also the DL Agriculture, pending, as is known, constitutional scrutiny);
the criteria and parameters referred to in the DM of July 2, 2024 (the "DM Suitable Areas") already partially annulled by the TAR Lazio in May of this year and currently sub judice before the Council of State.
The new regulation is now set out in arts. 11-bis and following of the TU Renewables.
Notably, similar to what was provided by Legislative Decree 199/2021, the following are considered suitable areas:
sites where plants of the same source are already installed and where modification interventions are carried out, even substantial ones, that do not involve a variation of the occupied area exceeding 20%, with the specification (this not present in the previous Art. 20 of Legislative Decree 199/2021) that such variation of the area is not allowed for photovoltaic plants installed on the ground in agricultural areas and that, for the new occupied areas, what is provided by Legislative Decree 22/2004 regarding cultural and landscape authorizations must be observed (cf. Art. 11-bis, co. 1, lett. a) of the TU Renewables);
sites subject to remediation identified pursuant to Legislative Decree 152/2006 (the "Environmental Code"), ceased quarries and mines, not recovered or abandoned or in conditions of environmental degradation, or portions of quarries and mines not susceptible to further exploitation as well as (in addition to what was provided by Legislative Decree 199/2021) landfills or closed or restored landfill lots (cf. Art. 11-bis; co. 1, lett. b), c) and d) of the TU Renewables);
sites and plants available to companies of the State Railways group, railway infrastructure managers, highway concessionaires, airport management companies as well as state property assets in use by the Ministry of Defense or the Ministry of the Interior and certain real estate assets identified by the State Property Agency (cf. Art. 11-bis, co. 1, lett. e), f), g), h) and i)).
Photovoltaic plants
The Decree then provides in art. 11-bis, co. 1, lett. l) ad hoc provisions for photovoltaic plants.
In essence:
areas adjacent to the highway network within a distance not exceeding 300 meters, buildings and industrial areas (to which are added areas destined for Data Center installation, areas used as parking lots, water reservoirs and areas within the perimeter of competence of the integrated water service) are confirmed as suitable areas;
the prohibition of installation of photovoltaic plants in agricultural areas within 500 meters from zones with industrial, artisanal and commercial destination appears confirmed (i.e., the previous prohibition introduced as a result of the DL Agriculture and relating to Art. 20, co. 8, lett. c-ter), 1) of Legislative Decree 199/2021);
the suitable areas referred to in the previous art. 20, co. 8, lett. c-ter, n. 2) are remodulated, in a restrictive key, (i.e., areas internal to establishments referred to in art. 268 of the Environmental Code and agricultural zones enclosed in a perimeter of 500 meters from the establishment) providing as conditions: (a) that the relative establishment is not destined for agricultural production and has been authorized with Integrated Environmental Authorization ("IEA"); (b) for agricultural zones a compression of the buffer zone from 500 to 350 meters;
those referred to in the previous Art. 20, co. 8, lett. c-quater (i.e., areas not included in the perimeter of assets subject to protection pursuant to Legislative Decree 42/2004) no longer appear to figure among the suitable areas.
Agricultural zones and agrivoltaic plants
The Decree appears to provide (finally) a definition aimed at identifying the so-called agrivoltaic plants different from advanced ones (for which an analytical illustration has been provided from the beginning for access to PNRR measures).
Specifically, the new art. 4, co. 1, lett. f-bis) defines as "agrivoltaic plants" photovoltaic plants that preserve the continuity of cultivation and pastoral activities on the installation site and that may (not must) provide for the rotation of modules placed in elevated position from the ground and the application of digital and precision agriculture tools.
This is a novelty of non-marginal importance considering that if, on one hand, the new discipline substantially confirms in art. 11-bis, co. 2, the generalized prohibition of installation of photovoltaic plants in agricultural areas, on the other hand, it provides an express derogation (in addition to CER and advanced agrivoltaic plants like the previous regulation) also for "standard" agrivoltaic plants as defined above provided that the modules are "placed in adequately elevated position from the ground".
Plants for biomethane production
With reference to plants for biomethane production, the previous discipline is essentially confirmed, although with some clarifications. In particular, the following continue to be suitable:
agricultural areas within 500 meters from zones with industrial, artisanal and commercial destination (i.e., the previous Art. 20, co. 8, lett. c-ter), 1) of Legislative Decree 199/2021);
areas internal to industrial plants and establishments referred to in art. 268 of the Environmental Code as well as areas classified as agricultural enclosed in a perimeter whose points are no more than 500 meters from the same plant or establishment with the specification, already mentioned for photovoltaic plants, that such establishments must be authorized under the IEA regime;
areas adjacent to the highway network within a distance not exceeding 300 meters.
As seen for photovoltaic technology, also for the projects in question those referred to in the previous art. 20, co. 8, lett. c-quater (i.e., areas not included in the perimeter of assets subject to protection pursuant to Legislative Decree 42/2004) no longer appear to figure among the suitable areas.
Regional Implementation
Following the pattern of what was provided by the previous art. 20, co. 4 of Legislative Decree 199/2021 in combination with the DM Suitable Areas, it is provided that within 120 days from the entry into force of the Decree (i.e., indicatively by May 22, 2026) the Regions shall provide, with their own law, for the identification of suitable areas based on the principles and criteria referred to in the new art. 11-bis, co. 4 of the TU Renewables, among which it is worth mentioning the following:
Regions cannot qualify as suitable areas included in the perimeter of assets subject to protection pursuant to the Code of cultural heritage and landscape nor those included in a buffer zone of three kilometers, in the case of wind plants, and five hundred meters, in the case of photovoltaic plants, from the perimeter of the same assets, nor identify suitable areas where the characteristics of the plants to be built are in contrast with the implementation rules provided by landscape plans (cf. Art. 11-bis, co. 4, lett. m) of the TU Renewables);
in order to preserve the agricultural destination of soils, agricultural areas qualifiable as suitable areas at regional level must not be less than 0.8% of the Utilized Agricultural Surfaces (UAS) nor more than 3% of the same UAS and specific percentages of UAS exploitation can be defined at municipal level;
impossibility of providing general and abstract prohibitions on the installation of renewable energy plants, without prejudice to the prohibitions and limitations prescribed for the installation of photovoltaic plants in agricultural areas pursuant to art. 11-bis, co. 2 and what is provided by article 11-quinquies of the Decree (according to which within the protection zones of UNESCO sites only the installation of renewable energy plants authorizable in free construction pursuant to Annex A of the TU Renewables is allowed).
In order to facilitate the identification of suitable areas (as well as acceleration zones), with a Decree of the MASE to be adopted within 60 days from the entry into force of the Decree, the operating procedures of a digital platform aimed at qualifying the territory and classifying areas and zones will be regulated.
As regards the 2030 targets for renewable energy capacity to be installed in each territory, the previous regional distribution referred to in the DM Suitable Areas remains confirmed.
Suitable areas at sea
The Decree introduces the concept of "suitable areas at sea" (cf. art. 11-ter of the TU Renewables) providing that such areas are those identified by maritime spatial management plans as well as disused oil platforms and ports (the latter, for wind plants with power up to 100 MW and subject to a variant of the port master plan to be approved within six months from the submission of the single authorization application).
Regime semplificato
Similar to what was provided by the previous art. 22 of Legislative Decree 199/2021, art. 11-quater of the Decree provides that for interventions falling (entirely and not partially) on suitable areas a simplified authorization regime applies.
Specifically, for such interventions it is not necessary to acquire landscape authorization (the opinion of the competent authority, where expressed, is not binding) and, in the case of projects subject to single authorization, the procedure terms are reduced by one third.
Preliminary considerations and market impacts
After approximately four years spent waiting for a concrete paradigm shift together with clear, precise and unambiguous indications on how and where to direct their investment strategies, it is highly probable that the Decree in question will lend itself to multiple criticisms from market operators, some of which can be easily anticipated from a plain reading of the discipline under examination.
The absence of transitional provisions and the disappearance of former c-quater areas
As is known, the TAR Lazio with sentence 9155/2025 partially annulled the DM Suitable Areas for the absence of a transitional discipline aimed at safeguarding proceedings in progress at the date of entry into force of the decree and pending the promulgation of Regional Laws.
The Decree appears to repeat exactly the same error, not providing any safeguard regime for consolidated legal positions and determining a potential retroactive effect of the new limitations on the multiple projects in the pipeline not in line with the renewed locational criteria (think, by way of example only, of the significant number of projects to be installed in former c-quater areas or former c-ter, 2) whose plants are not authorized under the IEA regime).
Furthermore, the rule does not appear to provide for an express repeal of the previous provisions while providing, in fact, their evident replacement with the new regime.
It is hoped that – in order to prevent the proliferation of litigation, likely to be accepted given also the precedent of the TAR Lazio – during the conversion into Law (i.e., by January 22 next) the course will be corrected, introducing the aforementioned safeguard clause; however, even in such an (optimistic) hypothesis, the result would consist of 60 days of total freezing of development initiatives, with inevitable negative effects on investments currently under evaluation or implementation by market players.
The same applies to buffer zones for protected assets.
The TAR Lazio, with the above-mentioned sentence, branded the DM Suitable Areas as illegal for an evident lack of proportionality in the part where it gave Regions the possibility to provide for buffer zones for protected assets up to 7 kilometers from the relative perimeter.
The Decree seems to resolve this issue at the root, striking out the previous c)-quater and providing, even, the impossibility for Regions to qualify as suitable the areas included in the perimeter of assets subject to protection regardless of the buffer zones that no longer have any relevance.
In other words, the realization of projects in proximity to protected assets is prevented once and for all regardless of any buffer zone.
The above would seem, barring changes during conversion, to considerably compromise the multiple initiatives previously suitable under art. 20, co. 8 lett. c)-quater currently under evaluation and, even, in the absence of transitional provisions, under authorization.
The IEA filter
Pursuant to the previous art. 20, co. 8, lett. c-ter) it was possible to install photovoltaic plants or for biomethane production on areas internal to industrial plants and establishments as well as in areas classified as agricultural enclosed in a perimeter whose points are no more than 500 meters from the same plant or establishment.
In compliance with the principle of maximum diffusion of renewable energies, the provision in question has been the subject of multiple extensive interpretations both by the executive and in judicial proceedings, going so far as to classify as "plant" even photovoltaic installations with power exceeding 20 kW as well as power plants and electrical substations (cf. MASE interpellation n. 130318 of August 8, 2023; TAR Lazio, Rome, Sentence n. 4994/2025; TAR Lecce, Sentence n. 1113/2025).
The above by virtue of a substantialist approach, aimed at considering as suitable areas with strong urban impact which, conversely, appears entirely neglected by the Decree.
The new art. 11-bis, co. 1, lett. l), num. 1) of the Decree, in fact, on one hand, circumscribes the radius of suitability of agricultural areas for photovoltaics to 350 meters (instead of 500) and, on the other hand, expressly requires (both for photovoltaics and for biomethane) that the relative plant or establishment be subject to IEA, significantly restricting the pool of usable sites compared to previous extensive readings.
This regulatory contradiction generates legal uncertainty and risks nullifying the interpretative efforts made to expand developable surfaces, creating an evident short circuit between the hermeneutic evolution favorable to renewables and the new restrictive discipline.
Consider, in fact, that many industrial plants, despite having a significant territorial impact, are not necessarily subject to IEA, which exclusively concerns facilities of considerable size and dedicated to activities with high and significant environmental impact, including, by way of example, the production and transformation of metals or the chemical industry.
Agricultural areas
Despite the DL Agriculture currently being pending constitutional judgment, the Decree appears, unfortunately, to essentially repropose the same generalized prohibition on the realization of ground-mounted photovoltaic plants in agricultural areas.
The only positive difference is represented by the introduction of the long-awaited definition of standard agrivoltaic plants which should be able to be realized in agricultural areas in derogation of the aforementioned prohibition.
Nevertheless, even in relation to this profile, significant margins of uncertainty appear to remain; in fact, the derogation finds application only where the modules are "placed in an adequately elevated position from the ground", which leaves immense spaces of discretion to the relative local administrations on what should be understood as "adequately elevated position".
During conversion it is appropriate, if not necessary, that clear and concrete technical criteria and parameters be provided aimed at limiting the randomness of administrative procedures and, at the same time, facilitating operators in planning their investment strategies.
Particularly perplexing are the constraints imposed on Regions in terms of agricultural areas qualifiable as suitable in their territory which, as seen, must not be less than 0.8% nor more than 3% of the UAS (i.e., the sum of company surfaces destined for agricultural production), also providing the possibility for municipalities to define specific percentages of UAS exploitation.
This is a mechanism that risks triggering, for each Region, a real race to start authorization procedures on agricultural areas in order to prevent possible risks of denial deriving from the erosion of the aforementioned 3% threshold.
Conclusions
The new regulation appears to close the circle of suitable areas returning, essentially, to the starting point with conditions and criteria, unfortunately, further restrictive compared to the previous legislation, going to defuse the positive effects introduced with Legislative Decree 199/2021.
This is clearly a discipline that is worse than the previous one and which, quite unexpectedly, appears not to have grasped – unlike national jurisprudence – the urgent need to definitively adopt an approach consistent with European principles of maximum diffusion of renewable sources, proportionality and environmental integration, making the achievement of the objectives set by the PNIEC by 2030 almost impossible.
Such a scenario consisting of yet another change in peius of sector legislation – in the absence of a substantial reforming intervention during conversion into Law – risks further fueling the current climate of regulatory uncertainty with inevitable negative effects on the entire sector as well as, in general terms, on the common objective of progressively building a solid and independent energy system.
A leap forward was needed and, unfortunately, for now, it seems that the executive, ignoring the signals coming from the market and administrative judges, has taken an unexpected step backward.
Article by Giovanni Battista De Luca, Piero Viganò and Lorenzo Piscitelli.
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