The PAS is a simplified procedure for the authorization to install and operate green-energy projects meeting the relevant requirements; the procedure is regulated by art. 6 of Legislative Decree no. 28/2011, whose applicative perimeter has been recently extended by means of Legislative Decree no. 77/2021 converted into Law no. 108/2021 (the “Semplificazioni Decree 2”) and Legislative Decree no. 17/2022 converted into Law no. 34/2022 (the “Energy Decree”).

The PAS is a declaration certifying the compliance of the solar-power plant with the local urban planning and building regulations and with the safety, health and hygiene standards.

Even if the PAS is a dated legal institute, the market interest (both national and international) for this procedure has recently flared up, due to a recent normative modification that extended PAS applicability also to high-power plants (in some cases up to 20 MW) starting from 2022.

According to art. 6 of Legislative Decree no. 28/2011 the PAS applies to:

  • solar plants with nominal power capacity of up to 20 MW, connected to the electricity grid in high and medium voltage, located in industrial, productive or commercial areas as well as in closed and restored landfills or in quarries not susceptible to further exploitation, in relation to which the competent public authority has certified the completion of environmental recovery and restoration activities;
  • solar plants with nominal power capacity of up to 10 MW to be built in areas qualified as suitable according to Article 20 of Legislative Decree no. 199/2021;
  • agri-voltaic plants that adopted innovative technical solutions with lifted-off modules located within 3 kilometers from industrial, artisanal and commercial areas.

As anticipated, the PAS consists of a declaration submitted by the interested party before the relevant Municipality certifying the compliance of the solar plant with the relevant regulation1 and therefore does not require the exercise of discretional powers (“poteri discrezionali”) by the Administration.

As indicated in Art. 6, par. 4 “[…] after the expiration of thirty days from the date of receipt of the declaration referred to in paragraph 2, the construction activity shall be deemed to be authorized”; the projects, therefore, shall be considered duly authorized after 30 days from the submission of the relevant documentation, and only after this date the construction works can start, since during the above-mentioned timeframe the Authority (i.e. the competent Municipality) can exercise its “inhibitory powers” and can therefore stop the project from being realized.

The mentioned inhibitory powers have restrictive nature (“natura vincolata”); thus, if within the controls to be performed during the first 30 days the Administration discovers any form of unlawfulness, it shall adopt a “reasoned order not to carry out the planned intervention” (see art. 6, paragraph 4).

Even if the PAS shall be considered “finalized” after the expiry of the 30-days period indicated in art. 6, paragraph 2, some legal risks still burden the project (and, therefore the power plant operator) after that period.

In particular, the mentioned legal risks shall be parted into the following three categories that will be following analysed:including, but not limited to (i) urban planning and building regulations and (ii) safety, health and hygiene standards.

• the non-completion of the PAS;

• the annulment of the authorization in “self-defence”;

• the challenge of the authorization.


If the operator (i) does not submit all the documentation required by the regulation, and/or (ii) submits false declarations to the Municipality, the silent consent mechanism of the PAS will not operate, and therefore the project cannot be considered duly authorized. In this case, at any moment the Municipality (or any PA potentially involved in the procedure) and any interested third party can require the project to be ceased and the pre-existent situation to be restored. It should also be noted that when the unlawfulness is merely formal (i.e. the project is compliant with the law, but there is only a lack of documentation) the Operator usually has the possibility to supplement the files submitted. The relevant risk is typically covered – at least partially – by the (mandatory) insurance of the technical advisor that will lead the project and, however, can be reduced by the execution of an indepth technical Due Diligence having at an object the legal and urbanistic compliance of the intervention.


After the expiration of the 30-days period, the Municipality cannot exercise the previously recalled inhibitory powers but can ex officio null the authorization in “self-defence” (“autotutela”).

In particular, the Municipality can null the PAS in accordance with art. 21-nonies of Law no. 241/1990 whether:

  • the project does not comply with the relevant regulation (for example because the area upon which it will be implemented is not suitable);
  • the dismantling (or the non-realization/completion) of the project is deemed to be of prevalent “public interest”;
  • less than 12 months have elapsed from the submission of the relevant documentation; the Administration, in the comparison of all the interests involved, considers the interest to dismantle (or to the non realization/completion) prevailing to the others.

In this regard, it should be stressed that in the overall analysis of the involved interest, the Municipality shall take into consideration also the “interest connected to the increasing of the production of less polluted energy with the benefits for the community” (see. TAR Sicily-Palermo, Sec. II, no. 596/2020); it is therefore clear that in a period of strong climate/energy emergency, the interest for the realization of a green-energy plant is particularly relevant.


Any interested party can challenge the PAS found to be unlawful; however, the timeline of such appealability is debated.

According to a first hypothesis, that equates the PAS to the notice of commencement (“Segnalazione Certificata di Inizio Attività – SCIA”), any interested party can ask the municipality to exercise the “self-defence powers” (“Poteri in autotutela”), under the conditions recalled in § II, within 12 months from the expiration of the 30-day period. In this case, if the Authority: expressly rejects the request, the applicant can challenge the decision before the competent Regional Administrative Tribunal (“TAR”) within 60 days or before the President of the Republic within 120 days; does not respond, the applicant can challenge the silent before the TAR as long as the silence last and, in any case, within the following 12 months.

According to this thesis, any interested third party can question the PAS lawfulness up to 12 months after its completion (which occurs 30 days after the submission of the documentation). In this case, however, the municipality shall act “in the form of self-defense” and, therefore, can block the project only if, in addition to the unlawfulness of the project, all the particularly stringent requirements of Article 21-nonies L. 241/1990 are met (see §III for a further assessment on the topic). According to a different thesis, the PAS is a “tacit administrative measure” (“Provvedimento amministrativo tacito”) formed by the silence-consent mechanism (Art. 20 L. 241/1990) and can be appealed before the Regional Administrative Court within 60 days or before the President of the Republic within 120 days running from (i) the expiration of the 30-day period or (ii) the knowledge of the project’s harmfulness.

In this regard, although there is no lack of indications to the contrary, the thesis that has recently found new support is the one sub (ii), which - if shared - implies that the time limit for the appealability starts running from the third party as “full acknowledgement” of the harmfulness of the tacit administrative measure, and, therefore, generally from the moment in which the profiles of illegitimacy of the intervention are recognizable.

The aforementioned thesis relies on the literal wording of Article 6, paragraph 4, of Legislative Decree 28/2011 (which uses the phrase “the activity shall be deemed to be authorized”) and it was recently shared by the Council of State, Sec. IV, judgments no. 1754/2022 and no. 9429/2022, according to which “if within thirty days the municipality does not express its reasoned dissent, [on the PAS ed.] the silence assent referred to in Article 20 of Law no. 241/1990 applies”.

Less recent but of certain relevance is also the sentence of the Council of State, Sec. IV, no. 4383/2020 according to which “This orientation [which assimilates the PAS to an SCIA, ed.], however, has been superseded, as not agreeable, in the terms set out, for all, by the judgment of the Section April 18, 2019, no. 2526, here endorsed. In general terms, [...], the difference between a tacit administrative measure formed by the silence-consent mechanism, as such appealable, and a private act such as the «denuncia di inizio attività», which is not appealable, is given by the rule of law governing the case. One is in the presence of a tacit measure if the private individual who makes the relevant request cannot begin the activity in question until after the lapse of a certain period of time, within which the administration can deny the good requested. On the other hand, there is a «private act» [atto privato ed.] if the interested party can immediately begin the activity, unless a broad act of control of the administration intervenes to inhibit him from doing so”. Applying this hypothesis, therefore, in the event of a challenge to the PAS, the Administrative Court may annul the measure deemed as unlawful.