Do I owe Italian excise on my rooftop PV ≤ 20 kW?

No. Renewable photovoltaic plants with available power (potenza disponibile) up to 20 kW are non sottoposti (outside the scope of excise) under Art. 52(2)(a) of the Testo Unico delle Accise (D.Lgs. 504/1995), as long as the electricity is self-consumed by the producer. Available power, not the DC peak rating of the modules in kWp, is what the threshold measures. No excise duty is owed and no AD-1 filing is required.

What if I export PV electricity to the grid?

Electricity exported to the grid (Scambio sul Posto or Ritiro Dedicato) goes to GSE or the local DSO and does not trigger an excise obligation for the producer: the supplier applies the duty downstream to the end customer. For plants above 20 kW, the self-consumed share can still be exempt under Art. 52(3)(b), but the AD-1 filing is still required.

Is residential PV ≤ 3 kW exempt?

Yes, on two grounds. It is non sottoposto thanks to the 20 kW threshold (Art. 52(2)(a)), and residential supplies up to 3 kW of contracted power with average monthly consumption of 150 kWh or less also qualify for the full exemption under Art. 52(3)(e) TUA.

What is impiego promiscuo (mixed use) under Art. 52(4) TUA?

Impiego promiscuo describes a power plant that feeds both exempt internal uses and taxable third-party uses. The trigger is when the power made available to third parties at the same delivery point exceeds 200 kW: at that point the entire power plant needs a licence and an AD-1 filing, and separate metering is required for each end use.

Which AD-1 quadri must a PV producer file?

A self-consuming PV producer above 20 kW in exempt self-consumption files a reduced set: Quadro A (production meter readings), Quadro G (outflows by type, which is where grid injection belongs), and Quadro L (exempt consumption by month and municipality, row L6). Plant identification is not a quadro: location and capacity in kW are declared in the power plant notice under Art. 53-bis(1) TUA. A non-renewable production plant, or one that is not purely exempt, files A, B, C, E, G, J, L, M, P, Q instead, plus the suppliers list.

When are the 2026 deadlines for PV declarants?

Under D.Lgs. 43/2025 the cadence is semi-annual: H1 (January-June) is due by September 30, 2026; H2 (July-December) is due by March 31, 2027. Taxable plants also pay monthly advances by the end of the month following the reference month (art. 7 DM 10 March 2026), so January consumption is paid by 28 February.

Photovoltaic Electricity Excise in Italy: Thresholds, Exemptions and AD-1 Filing in 2026

Italian electricity excise applies to photovoltaic output only in specific cases. The anchor rule is Art. 52(2)(a) of the Testo Unico delle Accise or Italian Excise Code (D.Lgs. 504/1995): renewable plants up to 20 kW of available power used for self-consumption are non sottoposti (outside the scope of excise), so they need neither a licence nor an AD-1 filing. Residential supplies up to 3 kW with average consumption of 150 kWh/month or less qualify for a further exemption under Art. 52(3)(e). For plants above 20 kW, electricity self-consumed by the photovoltaic self-producer for non-residential uses is generally exempt under Art. 52(3)(b), but the owner still runs a power plant and must file the AD-1. When the same delivery point serves more than 200 kW of third-party demand, impiego promiscuo (mixed use, Art. 52(4)) applies and the entire power plant becomes taxable. For 2026, under D.Lgs. 43/2025, the cadence is semi-annual: H1 is due September 30, 2026, H2 by March 31, 2027. For the general filing framework see the complete guide to the AD-1 declaration.

Quick definitions

Photovoltaic (PV): Plant that generates electricity from sunlight through photovoltaic conversion. For excise purposes, a textbook renewable source governed by Art. 52 TUA.
Self-consumption (autoconsumo): The share of electricity produced and consumed by the same entity that owns the plant, with no supply to third parties. This is the deciding variable for the exemption.
Available power (potenza disponibile): The power the plant can actually deliver, which for photovoltaic means the inverter or connection power rather than the DC peak rating of the modules (kWp). This is the figure Art. 52 TUA measures against the 20 kW threshold, so a 24 kWp array behind a 20 kW inverter stays below it.
Non sottoposto vs. esente: A key distinction. Non sottoposto = outside the scope of excise duty (no obligations at all). Esente = inside the scope but at a zero rate (the power plant still exists and the AD-1 must still be filed).
Impiego promiscuo (mixed use): Setup where a power plant feeds both exempt and taxable uses. When the power available to third parties at the same delivery point exceeds 200 kW (Art. 52(4)), the entire plant becomes taxable.
RIU (internal user grid, rete interna di utenza): A private network under Art. 33 of Law 99/2009 that connects multiple consumption units to one or more generation plants without a public-grid connection. For excise purposes, it counts as a power plant whose declarant category is "self-consumer" or "seller-distributor".
BESS (battery storage): Electrochemical storage system. If charged only from PV for self-consumption, it does not affect the exemption. If charged from the grid and discharged to third parties, it can count as a supply and trigger excise duty.
Semi-annual cadence: Filing frequency introduced by D.Lgs. 43/2025: H1 due September 30, H2 due March 31 of the following year. Replaces the previous single annual filing on March 31.

When excise applies to PV electricity

The answer turns on three variables: available power, where the electricity goes (self-consumption or supply), and type of end user (residential or non-residential). Their combination places the plant in one of four bands:

Non sottoposto - self-consuming plants up to 20 kW. No ADM obligations at all.
Exempt, residential - household supplies up to 3 kW with average consumption of 150 kWh/month or less (Art. 52(3)(e)). The supplier applies the exemption to the end customer.
Exempt with filing obligation - non-residential self-consuming plants above 20 kW (Art. 52(3)(b)). The owner runs a licensed power plant, files the AD-1, and pays zero on the self-consumed kWh.
Taxable - paid supply to third parties and any setup that falls under impiego promiscuo above 200 kW.

The 20 kW threshold (Art. 52(2)(a) TUA)

The 20 kW threshold is the first dividing line and the one most often misread, starting with the metric itself: the statute measures available power, not the nameplate rating or the DC peak rating of the modules. ADM practice (notice prot. 38562/RU of January 31, 2020) clarifies how this works out for a single plant:

The test is available power, not the DC peak rating printed on the modules. A 24 kWp array behind a 20 kW inverter has 20 kW of available power and stays outside the scope of excise; the kWp figure alone does not decide the question.
Batteries and storage do not count toward the threshold if charged exclusively from renewable sources: the notice excludes them explicitly.
A revamping that pushes available power to 21 kW takes the plant out of the non sottoposto band: from that moment it is a power plant. Art. 53-bis(1) TUA requires the notice to be filed in advance, that is before the activity starts, because what begins here is a new activity. The thirty-day term set by Art. 53-bis TUA covers changes at a plant that is already a power plant, corporate changes and cessation.

One point falls outside this notice and has no single public ADM source: whether and how the available power of several distinct plants belonging to the same holder is added together when they share a point of connection (POD) or were authorized under separate titles at different times. Absent excise-specific guidance on the point, we do not state an aggregation rule here: check the specific case with the territorially competent Customs Office before installing multiple sub-threshold plants at the same point of connection.

Residential exemption ≤ 3 kW (Art. 52(3)(e) TUA)

For the residential segment two favourable regimes overlap. PV ≤ 20 kW is already non sottoposta; in addition, supplies to a primary residence (residenza anagrafica) with contracted power ≤ 3 kW and average monthly consumption ≤ 150 kWh enjoy a full exemption on the entire supply (including the share drawn from the public grid). The benefit is administered directly by the supplier, who does not bill the excise; the PV producer is not involved.

Plants > 20 kW in non-residential self-consumption (Art. 52(3)(b) TUA)

The textbook case: industrial rooftop, winery, hotel, livestock farm with a 50-500 kW rooftop array. The Art. 52(3)(b) exemption states that electricity from renewable plants self-consumed by the producer at its own premises is not subject to excise. However all formal obligations remain:

Power plant notification to the competent ADM office, filed in advance of the start of the activity (Art. 53-bis(1) TUA).
Acquisition of the operating licence (codice ditta) on the basis of that notification.
Posting of collateral at 15% of the projected annual excise liability (art. 10 DM 10 March 2026).
Installation of UTF/ADM fiscal meters measuring gross and net production.
Semi-annual AD-1 filings.

Mixed use: when the power plant feeds > 200 kW (Art. 52(4) TUA)

Art. 52(4) is the anti-avoidance clause. When a power plant simultaneously supplies exempt and taxable uses, and the power made available to third parties at the same point of delivery exceeds 200 kW, the entire plant falls into impiego promiscuo. Consequence: all generated electricity is treated as taxable unless the exempt destination is proven through separate metering. Concrete example: an 800 kW PV park serving an industrial consortium where a single off-taker draws more than 200 kW qualifies the entire plant as mixed use; separate meters per off-taker are mandatory, the readings go into the measurement quadri B, C and E, and consumption is split across quadri J, L and M according to its tax status.

Which AD-1 quadri a PV producer must compile

The mix of quadri depends on the declarant category. One misconception to clear first: no quadro serves to identify the plant. Location, plant type, capacity in kW and expected annual kWh are declared in the power plant noticeunder Art. 53-bis(1) TUA, while the declarant's details sit in the cover sheet (frontespizio). Quadri A to E are fiscal measurement quadri: meter rows with serial number, current reading, previous reading, difference, reading constant and kWh.

Quadro	When a PV producer compiles it
A - Production	Always. Readings from the fiscal production meters: how many kWh the plant generated in the period.
G - Outflows by type	Whenever energy leaves the plant. Grid injection, supply to other power plants, transmission, release from storage: each outflow under its own destination code.
L - Exempt consumption	Always for exempt self-consumption. One block per month and municipality; PV above 20 kW fills in row L6 (Art. 52(3)(b)).
B, C, E	Only for plants that are not purely exempt: electricity purchased, breakdown of own consumption, metered transfers.
J, M	The other two consumption quadri: J for out-of-scope consumption, M for taxable consumption. A purely exempt PV producer files neither.
P, Q	Excise settlement by territorial area and summary of the balance. Present whenever there is tax to settle.

2026 deadlines for PV declarants

The unified calendar introduced by D.Lgs. 43/2025 applies to photovoltaic producers as well:

H1 2026 (1 January - 30 June 2026): AD-1 filing due by 30 September 2026.
H2 2026 (1 July - 31 December 2026): AD-1 filing due by 31 March 2027.
Monthly advance payments: for taxable plants, settlement by the end of the month following the reference month (art. 7 DM 10 March 2026), so January consumption is paid by 28 February. Purely exempt producers pay no advances.
Change notifications: every change of power, declarant or configuration (e.g. installation of a grid-connected BESS) must be notified to ADM within 30 days.

Common mistakes in PV declarations

Measuring the threshold on a single string: the parameter in Art. 52(2)(a) TUA is the available power of the plant, not that of a section or of a single inverter. Reducing the test to whichever subset is most convenient is a recurring error that ADM picks up in inspections.
Conflating non sottoposto with esente: filing an AD-1 in "exempt" mode for a ≤ 20 kW plant is not just superfluous - it creates a power plant entry in the ADM register that cannot be reversed without procedure.
Forgetting the 200 kW trigger: crossing the third-party-available power threshold without reconfiguring the metering and accounting is the classic case disputed in consortia and shopping centres.
Adding a regional surcharge: PV producers selling to third parties sometimes add a regional, provincial or municipal addizionale on top of the national excise. None applies to electricity. The municipal surcharge was abolished by Art. 2(6) D.Lgs. 23/2011 and the provincial one by Art. 18(5) D.Lgs. 68/2011 from 1 January 2012, and Art. 4(10) DL 16/2012 repealed Art. 6 DL 511/1988 outright from 1 April 2012, which also covers the special-statute regions and the Autonomous Provinces of Trento and Bolzano. Constitutional Court judgment 43/2025 confirmed this retroactively. A regional surcharge survives only for natural gas, which is outside the scope of an electricity AD-1. Billing one to your customers means charging tax that is not owed.
Late notification of a revamping that pushes available power beyond 20 kW: the notice is advance (Art. 53-bis(1) TUA), not within thirty days, because the plant becomes a power plant for the first time. Operating it beforehand amounts to unauthorised operation with administrative sanctions.