Suitable Areas, conversion into law approved

Parliament reverses course on AIA and introduces a transitional regime. Common sense prevails, but several critical issues remain

With the enactment of Decree No. 175 of 21 November 2025, originally intended to regulate exclusively the tax credits under the Transition Plan 5.0 (the “Decree”), a sense of discouragement and disillusionment spread among market operators, due to yet another setback resulting from the new regime governing suitable areas for the development of renewable energy plants in Italy.

Specifically, the Decree

• repealed the provisions on suitable areas set out under Article 20, paragraph 8 of Legislative Decree No. 199 of 2021 (and, as a consequence, also the Agriculture Decree, which is currently pending constitutional review), as well as the criteria and parameters laid down in the Ministerial Decree of 2 July 2024 (the “Suitable Areas Ministerial Decree”, already partially annulled by the Lazio Regional Administrative Court in May 2025 and currently sub judice before the Council of State);

• introduced into Legislative Decree No. 190 of 2024, also known as the Consolidated Act on Renewable Energy Sources (“TU FER”), a new normative framework governing suitable areas (Articles 11-bis et seq. of the TU FER).

As noted, the amendments introduced by the Decree generated significant concerns and uncertainties, in particular, on the one hand, due to the introduction of the requirement of an Integrated Environmental Authorization (“AIA”) for industrial plants, within which a radius of suitability had to be assessed, and, on the other hand, due to the absence of a transitional regime applicable to projects already undergoing authorization procedures under the repealed framework.

With the conversion into law of the Decree, currently under publication in the Official Gazette (the ConversionLaw), while these critical issues have, on the one hand, been resolved, on the other hand further concerns of no minor relevance have emerged for future development initiatives.

In this respect, the full list of the various categories of suitable areas, as amended by the Conversion Law, is set out below.

Specifically, the following are deemed suitable areas.

• Sites where plants producing energy from the same renewable source are already installed and where modification works, including substantial ones, are carried out, provided that they do not entail an increase in the occupied area exceeding 20 percent, with the clarification, not included in the previous Article 20 of Legislative Decree No. 199 of 2021, that such variation in area is not permitted for ground mounted photovoltaic plants installed in agricultural areas. In addition, for the newly occupied areas, compliance is required with the provisions of Legislative Decree No. 42 of 2004 concerning cultural heritage and landscape authorizations (see Article 11-bis, paragraph 1, letter a of the TU FER).

• Sites subject to remediation identified pursuant to Legislative Decree No. 152 of 2006 (the Environmental Code), exhausted quarries and mines, not restored or abandoned or in conditions of environmental degradation, or portions of quarries and mines no longer capable of further exploitation, as well as, in addition to what was previously provided for under Legislative Decree No. 199 of 2021, closed or remediated landfills or landfill lots (see Article 11-bis, paragraph 1, letters b, c and d of the TU FER).

• Sites and facilities available to companies of the Ferrovie dello Stato group, railway infrastructure operators, motorway concessionaires, airport management companies, as well as State owned assets used by the Ministry of Defense or the Ministry of the Interior, and certain real estate assets identified by the State Property Agency, after consultation with the Ministry of Economy and Finance, and, as introduced at conversion stage, the Ministry of Agriculture, Food Sovereignty and Forestry, in the case of State owned assets with an agricultural designation not included in enhancement or disposal programs falling within their respective competences (see Article 11-bis, paragraph 1, letters e, f, g, h and i).

Photovoltaic plants

Article 11-bis, paragraph 1, letter l provides for further and additional cases of suitability specific to photovoltaic plants. These include

• areas adjacent to the motorway network within a distance not exceeding 300 meters.

• buildings, constructed structures and their related external appurtenant surfaces.

• areas designated for industrial, office, artisanal, commercial and logistics uses, as well as areas intended for the installation of Data Centers.

• areas used as parking facilities, limited to covering structures.

• water reservoirs, quarry lakes and decommissioned mines or mines in conditions of environmental degradation.

• areas within the perimeter of competence of the integrated water service.

• areas located within industrial plants and facilities not intended for agricultural or livestock production, nor for the production of energy from renewable sources pursuant to Article 268 of the Environmental Code, as well as agricultural zones enclosed within a perimeter of 350 meters from such plant or facility (during the conversion process the requirement that the relevant facility be authorized by means of an AIA was removed, while the reduction of the buffer zone from 500 to 350 meters was confirmed).

Even at conversion stage, the previous Article 20, paragraph 8, letter c-quater, considering as “suitable” those areas not included within the perimeter of assets subject to protection pursuant to Legislative Decree No. 42 of 2004, was not reinstated. This provision was recently confirmed by the Lombardy Regional Administrative Court, Milan, Section III, judgment No. 4300 of 30 December 2025, in continuity with other administrative case law (see Piedmont Regional Administrative Court, Section II, 19 October 2023, No. 808 and Tuscany Regional Administrative Court, Section II, 8 July 2024, No. 844), as constituting an additional category of suitable area, expanding the list set out in paragraph 8.

Furthermore, the text approved by Parliament eliminated existing renewable energy plants from among the reference points for identifying suitable areas for the development of new renewable plants, thus curbing the expansive interpretation that had consolidated following the MASE ruling No. 130318 of 8 August 2023 and had subsequently been endorsed by administrative case law as well (inter alia Regional Administrative Court of Lazio, Rome, judgment No. 4994 of 2025, and Regional Administrative Court of Lecce, judgment No. 1113 of 2025).

Agricultural areas and agrivoltaic plants

As is well known, the Decree finally introduced the long-awaited definition of standard agrivoltaic plants, defined as “photovoltaic plants that preserve the continuity of agricultural and pastoral activities at the installation site. To ensure such continuity, the plant may provide for the rotation of modules installed in an elevated position above ground and the application of digital and precision agriculture tools”.

On this point, the Conversion Law introduces important clarifications to be borne in mind during the authorization phase:

• For the installation of agrivoltaic plants, project developers are required to obtain a sworn technical statement, to be attached to the project submitted during the authorization phase and in any event to be made available to the administration for control activities, drafted by a qualified professional, certifying that the plant is suitable to preserve at least 80 percent of the gross marketable production.

• The municipality with territorial jurisdiction is granted a five-year power, following the construction of an agrivoltaic plant, to verify the continued suitability of the installation site for agricultural and pastoral use.

• The restoration of the site is provided for, together with the application of an administrative pecuniary sanction ranging from EUR 1,000 to EUR 100,000, in relation to agrivoltaic installations that do not ensure the preservation of the continuity of agricultural and pastoral activities at the installation site[1].

These amendments raise significant concerns, given the structural limitations in terms of resources and expertise of municipal technical offices, as well as the intrinsic difficulty of certifying ex ante a value that is heavily influenced by unpredictable factors, such as climate, and that can only be determined ex post, all the more so in relation to land currently uncultivated or where crop use will change.

Further critical issues arise from the novelty related to the five year verification power granted to municipal administrations which, in addition to being potentially used instrumentally by local authorities, risks conferring considerable uncertainty on the robustness of projects acquired or developed by market players, precisely due to the generic and abstract nature of the parameters to be applied under the Conversion Law.

Biomethane production plants

Regarding biomethane production plants, the amendments to the regulatory framework introduced by the Decree appear limited but not without consequences. In particular, the following are deemed suitable.

• Agricultural areas within 500 meters of zones designated for industrial, artisanal and commercial use, corresponding to the former Article 20, paragraph 8, letter c-ter, number 1 of Legislative Decree No. 199 of 2021, which, as noted, no longer applies to photovoltaic plants.

• Areas located within industrial plants and facilities referred to in Article 268 of the Environmental Code, as well as areas classified as agricultural enclosed within a perimeter whose points are no more than 500 meters from the same plant or facility.

• Areas adjacent to the motorway network within a distance not exceeding 300 meters.

As with photovoltaic technology, also for biomethane production projects the areas referred to under the former Article 20, paragraph 8, letter c-quater, namely areas not included within the perimeter of assets subject to protection pursuant to Legislative Decree No. 42 of 2004, are no longer included among suitable areas.

The role of the Regions

In line with the provisions of the former Article 20, paragraph 4 of Legislative Decree No. 199 of 2021, read in conjunction with the Suitable Areas Ministerial Decree, it is provided that within 120 days from the entry into force of the Decree, that is by 22 March 2026, the Regions, and within 180 days from the same date, that is by 21 May 2026, each autonomous province, ensuring the appropriate involvement of local authorities, shall identify suitable areas by means of their own legislation, on the basis of the principles and criteria set out in the new Article 11-bis, paragraph 4 of the TU FER, including, inter alia, the following:

• Regions may not qualify as suitable those areas included within the perimeter of assets subject to protection pursuant to the Cultural Heritage and Landscape Code, nor those included within a buffer zone of three kilometers, in the case of wind plants, and 500 meters, in the case of photovoltaic plants, from the perimeter of such assets, nor may they identify suitable areas where the characteristics of the plants to be developed conflict with the implementing rules provided for under landscape plans (see Article 11-bis, paragraph 4, letter m of the TU FER).

  On this point, industry associations have also expressed their views, highlighting the critical issue reported by certain Regions regarding the difficulty of identifying enough suitable areas in relation to the assigned regional targets. In practice, these difficulties result in a substantial impossibility of achieving renewable energy development targets within the prescribed timeframes, with the consequent risk of undermining national and European objectives.

• To preserve the agricultural designation of land, agricultural areas that may be classified as suitable areas at regional level must not be less than 0.8 percent nor more than 3 percent of the utilized agricultural area (SAU)[2], including the surface occupied by agrivoltaic plants, as specified by the Conversion Law.

• A different maximum limit may be provided for each municipality, without prejudice to the regional limits set out above, namely between 0.8 percent and 3 percent of the SAU. This wording was introduced during parliamentary review to replace the previous formulation which merely stated that specific percentages of SAU exploitation could be defined at municipal level, to expressly attribute such competence to regions and autonomous provinces and to overcome potential interpretative uncertainties as to the authority responsible for determining thresholds at municipal level.

• The introduction of general and abstract prohibitions on the installation of renewable energy plants is precluded, without prejudice to the prohibitions and limitations prescribed for the installation of photovoltaic plants in agricultural areas pursuant to Article 11-bis, paragraph 2, and to the provisions of Article 11-quinquies of the Decree, pursuant to which within the protection zones of UNESCO sites only renewable energy plants eligible for authorization under free building activity pursuant to Annex A of the TU FER are permitted.

Offshore suitable areas

The Decree introduces the concept of offshore suitable areas, pursuant to Article 11-ter of the TU FER, providing that these include areas identified by maritime spatial planning management plans, as well as decommissioned oil platforms and ports. The latter are eligible for wind plants with a capacity of up to 100 MW, subject to a port master plan amendment to be approved within six months from the submission of the application for the single authorization.

Simplified regime

In line with the former Article 22 of Legislative Decree No. 199 of 2021, Article 11-quater of the Decree provides that a simplified authorization regime applies to projects located entirely, and not partially, within suitable areas.

Specifically, for such projects it is not necessary to obtain a landscape authorization. Any opinion issued by the competent authority is not binding. Moreover, in the case of projects subject to a single authorization, the procedural time limits are reduced by one third.

The introduction of transitional provisions and the disappearance of the former c-quater areas

Initially, the Decree repeated the same error as the Suitable Areas Ministerial Decree, by failing to provide any safeguarding regime for ongoing procedures, thus giving rise to a potential retroactive effect of the new limitations on numerous pipeline projects not compliant with the revised siting criteria. It should be recalled that the Regional Administrative Court of Lazio, by judgment No. 9155 of 2025, partially annulled the Suitable Areas Ministerial Decree on this very point. Parliamentary review has now introduced a transitional regime aimed at safeguarding all projects whose authorization procedures were already underway as of the entry into force of the Decree.

Specifically, it is established that the provisions set out under Articles 11-bis, paragraph 1, and 11-quater of the TU FER, as introduced by the Decree, do not apply to procedures pending as of the date of entry into force of the Decree, that is 22 November 2025, which shall therefore continue to be governed by the previous regulatory framework. It is further clarified that pending procedures include enabling or authorization procedures, including environmental assessment procedures, for which the verification of the completeness of the documentation submitted in support of the project has been completed as of the date of entry into force of the Decree. In addition, in cases of high agricultural value of the area, the competent Region or autonomous province may resort to the opposition remedy provided for under Article 14-quinquies of Law No. 241 of 7 August 1990.

However, the issue immediately arises as to how to determine when the completeness of the documentation submitted in support of the project is deemed to be completed for all simplified procedures, such as the simplified authorization procedure (PAS), for which the completeness check is not, in practice, formally carried out. Depending on a systematic or literal interpretation of the provision, this could lead either to considering as safeguarded all projects whose filing was completed at least thirty days prior to 22 November 2025, in compliance with Article 8 of the TU FER, or, conversely, to considering the completeness of documentation not verified for all those procedures for which no formal confirmation of completeness has been issued, even though the thirty day term has already elapsed.

Finally, about the former c-quater provision, which had been the basis for numerous project initiatives since its introduction, the exclusion from the list of suitable areas of those not included within the perimeter of assets subject to protection pursuant to Legislative Decree No. 42 of 2004 has been confirmed.

Agricultural areas

Although the Agriculture Decree is currently subject to constitutional review, the Decree unfortunately appears to essentially reintroduce the same general prohibition on the construction of ground mounted photovoltaic plants in agricultural areas.

The only positive difference lies in the introduction of the long-awaited definition of standard agrivoltaic plants, which should be eligible for installation in agricultural areas by way of derogation from the prohibition.

Nevertheless, significant margins of uncertainty remain also in this respect. Indeed, the derogation applies only where the modules are installed in a position adequately elevated above ground, which leaves extensive discretion to local administrations as to what should be considered an adequately elevated position.

It is appropriate, if not necessary, for clear and concrete technical criteria and parameters to be provided, aimed at limiting the uncertainty 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 that may be classified as suitable within their territory, which, as noted, must not be less than 0.8 percent nor more than 3 percent of the SAU, that is the aggregate surface area designated for agricultural production, while also providing for the possibility for municipalities to define a different maximum limit, without prejudice to the regional limits set out above.

This mechanism risks triggering, within each Region, a genuine race to initiate authorization procedures on agricultural land to prevent potential risks of refusal deriving from the erosion of the 3 percent threshold.

Although the range identified for suitable areas, while presented as a measure to protect agricultural land, does not in reality constitute an effective constraint on the growth of utility scale photovoltaic installations from a purely quantitative perspective, given that 3 percent of the SAU would be sufficient to develop far more capacity than required to meet energy demand, it is reasonable to expect that a significant portion of the areas theoretically deemed suitable will not present technically and economically sustainable grid connection conditions. This would result, as is already the case, in opportunistic project development, excessive micro zonal concentration and a loss of efficiency of the authorization and energy system, to the detriment of the community as a whole.

Conclusions

The regulatory framework outlined by the Conversion Law undoubtedly marks a turning point in the discipline of suitable areas for the development of renewable energy sources, addressing some of the most evident critical issues that emerged in the original version of the measure.

In particular, the introduction of a transitional regime for ongoing procedures and the removal of disproportionate requirements, such as the mandatory possession of an AIA for the identification of industrial buffer zones, represent corrective measures that are both welcome and, in several respects, necessary to restore a minimum level of legal certainty for operators.

Nevertheless, the overall structure of the reform continues to present significant areas of friction.

The definitive exclusion of the former Article 20, paragraph 8, letter c-quater of Legislative Decree No. 199 of 2021 significantly reduces the scope of areas that may be classified as suitable, in apparent misalignment with the case law that had emphasized its expansive and systematic function. Similarly, the continuing general prohibition on ground mounted photovoltaic plants in agricultural areas, mitigated only by the derogation for standard agrivoltaic plants, continues to rely on elastic and indeterminate formulations that risk translating, in practical application, into an excessive expansion of administrative discretion.

The decision to bind Regions to rigid percentage thresholds of SAU qualifying as suitable areas also appears particularly delicate.

Although formally oriented towards the protection of agricultural land, this mechanism risks producing distortive effects, encouraging anticipatory competition among projects, suboptimal locational concentration and an increase in initiatives lacking genuine technical and economic sustainability, with negative repercussions on the overall efficiency of the authorization system and on the achievement of decarbonization objectives.

In conclusion, the legislator has taken a step forward in the attempt to rationalize a stratified and highly contentious field. However, the outcome still appears far from a framework that is truly stable, coherent and functional to national and European objectives, and responsive to the concerns of market operators.

Much will depend, in the coming months, on the regional implementation of the new regulatory framework, on the adoption of digital tools supporting territorial planning and, not least, on the clarifying contribution that may be provided by administrative case law.

In the absence of further fine-tuning interventions, the risk remains that the discipline of suitable areas will continue to represent not so much a factor of acceleration, but rather an additional source of uncertainty for the orderly development of renewable energy sources in Italy.

[1] Such administrative sanction is also provided for the construction of ground mounted photovoltaic plants carried out in breach of the prohibition set forth under Article 11-bis, paragraph 2 of the TU FER.

[2] Currently equal to 12,3 million hectares, source ISTAT (2025): https://www.istat.it/storage/ASI/2025/capitoli/C13.pdf compared with a renewable energy generation target for 2040 ranging between 144 GW and 170 GW, source Terna (2025): https://download.terna.it/terna/Terna_Prospettive_Sviluppo_Sistema_Energetico_2050_Copertura_domanda_elettrica_8de15802728e7d1.pdf.