Connecting a photovoltaic installation to the Italian electricity grid involves a structured sequence of steps distributed across multiple regulatory bodies. For rural installations — which include most agrivoltaic farms — the connection pathway depends primarily on the system's rated capacity and the voltage level at which it will interface with the grid. Two distinct procedures exist: a simplified track for smaller systems and an ordinary track for medium-to-large installations.
The Three Entities in the Italian Connection Process
Every grid connection request in Italy involves at least two and sometimes three distinct organisations, depending on the system size:
- Local distribution network operator (DSO): In most of Italy, this is E-Distribuzione (a subsidiary of Enel). In some urban and northern areas, the role is filled by Areti (Rome), Unareti (Milan), or Ireti (Genoa and Parma). For systems connecting at low or medium voltage, the DSO manages the entire connection process independently of TERNA.
- TERNA: The national transmission system operator. TERNA becomes involved only when the system connects at high voltage (above 35 kV) or when its capacity exceeds the thresholds that require transmission-level analysis. Agrivoltaic farms above approximately 10 MW typically fall within TERNA's scope.
- GSE: The energy services manager. The GSE does not manage the physical grid connection but is required for incentive registration and for the issuance of the POD (Point of Delivery) code for production plants. The GSE's involvement begins after the physical connection is complete.
Simplified Connection Procedure
The simplified procedure applies to photovoltaic systems with a rated power of 200 kW or less that connect at low voltage. This track was introduced to reduce administrative friction for small rural installations, including rooftop systems on farm buildings and small ground-mounted arrays in agricultural parcels.
Under the simplified procedure, the DSO processes the connection request within 20 business days of receiving a complete application. Physical connection works and metering installation are completed within 30 days of request acceptance. Total connection costs under this track typically range from €100 to €350, depending on the distance to the nearest low-voltage connection point and the complexity of metering equipment required.
No preliminary technical study is required at this scale. The DSO confirms feasibility based on existing network data and proceeds directly to cost estimation and connection works scheduling.
Ordinary Connection Procedure
Systems exceeding 200 kW, or any system regardless of size connecting at medium or high voltage, follow the ordinary procedure. This track involves a multi-stage technical assessment before physical connection works begin.
Stage 1 — Preliminary Technical Assessment
The applicant submits a formal connection request through the DSO's portal, accompanied by technical documentation including a site plan, estimated capacity, voltage level requested, and a preliminary single-line diagram. The DSO conducts a network feasibility analysis within 20 business days and issues a preliminary response indicating whether connection at the requested point and voltage is technically possible.
Stage 2 — Cost Estimate (Preventivo)
If the preliminary assessment is positive, the DSO prepares a detailed cost estimate covering all works required on the DSO's network side: cable laying, transformer upgrades, protection relay installation, and metering equipment. The estimate is delivered within 30 to 60 business days. The applicant has 45 days to accept or reject the estimate. Rejection at this stage requires the applicant to submit a new connection request.
Stage 3 — Connection Works and Testing
Upon acceptance of the estimate and payment of the connection deposit, the DSO schedules and executes connection works. The works phase typically runs up to 90 business days for medium-voltage connections, and up to 180 days for high-voltage connections requiring substation modifications. On completion, the DSO conducts acceptance testing and issues the connection certificate.
Stage 4 — GSE Registration and POD Assignment
Following physical connection, the system operator submits a production plant registration request to the GSE. The GSE assigns a unique POD code to the production unit, which is required for all subsequent incentive applications and energy accounting. This stage adds 15 to 30 business days to the overall timeline.
TERNA-Level Connection for Large Agrivoltaic Farms
For installations with capacity above approximately 10 MW, TERNA's involvement becomes necessary. The TERNA connection procedure operates on a separate and longer timeline than the DSO procedure.
| TERNA Procedure Stage | Indicative Timeline |
|---|---|
| Estimate processing | 90 days |
| Estimate acceptance window | 120 days |
| Release of approval (autorizzazione) | 60 days |
| Authorization process initiation | 120 days |
| STMD (Studio di Rete) processing | 90 days |
| STMD acceptance | 60 days |
| Construction and commissioning | Variable — typically 6–18 months |
The STMD (Studio Tecnico di Massima Definizione) is a network impact study that TERNA conducts to assess how the new generation unit affects power flow, voltage stability, and protection coordination across the transmission network. For agrivoltaic farms in areas with existing generation concentration — such as parts of Puglia where installed renewable capacity already approaches local consumption peaks — the STMD may require specific mitigation measures: reactive power compensation, curtailment agreements, or upgrade of nearby transmission elements.
Costs for Ordinary and TERNA-Level Connections
Cost ranges for ordinary connections are considerably wider than for the simplified procedure:
- Medium-voltage connection (200 kW – 10 MW): €1,000 to €6,000 in DSO-charged fees, plus the cost of any DSO network reinforcement works passed to the applicant.
- High-voltage or transmission-level connection (above 10 MW): fees and network reinforcement costs vary significantly by location. In areas with adequate existing capacity, reinforcement costs may be minimal. In constrained zones, costs for cable or substation upgrades attributable to the new plant can reach several hundred thousand euros.
These cost estimates cover only the connection point and DSO/TERNA network works. Client-side works — cables from the solar array to the connection point, inverters, protection relays, metering cabinets, and civil works — are the applicant's sole responsibility and are not reflected in the connection cost estimates.
Rural-Specific Considerations
Agricultural zones present specific challenges for grid connection that are less common in urban or industrial settings. Connection cable routing through cultivated land requires negotiation of easements with neighboring landowners. Rural medium-voltage networks in southern Italy — particularly in Puglia, Sicily, and Basilicata — were not designed with high-density generation injection in mind, and many older rural feeders have limited reverse-flow capacity.
The DSO has in recent years published "connection availability maps" (mappe di disponibilità di connessione) that indicate, by zone, the estimated available capacity on existing medium-voltage feeders. Agrivoltaic developers are advised to consult these maps before selecting a connection point, as zones with zero available capacity effectively require network reinforcement as a condition of any new connection — adding cost and time to the process.
In some cases, nearby agrivoltaic developers have coordinated collective connection requests to share the cost of a single medium-voltage line upgrade, reducing per-project connection expenditure. This approach requires formal coordination through the DSO and is documented in TERNA's published connection procedure guidelines.
Interaction with Environmental Permitting
Grid connection approval is administratively separate from environmental and land-use permits, but the two processes must converge before construction begins. Large agrivoltaic installations require an environmental compatibility decree (Decreto VIA) or, for smaller systems, a simplified environmental procedure (Verifica di assoggettabilità). The connection request can be initiated in parallel with the environmental permit, but construction cannot proceed until both approvals are in hand.
TERNA's official connection procedure documentation is available at terna.it.