Methodology — SolarSymb

Legal Basis

SolarSymb implements the Italian regulatory framework for ground-mount photovoltaic installations as defined by:

D.Lgs. 190/2024 (Testo Unico FER) — consolidated renewable energy law
Legge 15 gennaio 2026, n. 4 — Art. 11-bis (aree idonee), Art. 12-bis (SAU cap)
D.Lgs. 178/2025 — corrective decree, revised Annexes A–D
D.Lgs. 42/2004 — Codice dei Beni Culturali e del Paesaggio (landscape constraints)
L. 394/1991 — EUAP protected areas
Ramsar Convention — wetland protection
PAI / PGRA — flood risk management (D.Lgs. 49/2010)

WFS layers for Natura 2000, EUAP, Ramsar, PTPR landscape constraints, CUS 2016 land cover, coastal/lake buffers. Accessed via OWSLib + HTTP fallback.

National flood risk zones (PGRA R1–R4) via WFS with GML fallback. Covers the Appennino Centrale hydrographic district.

Motorway network (highway=motorway), railway lines (railway=rail), and electrical substations (power=substation) for Lazio.

Solar irradiance and PV yield data. SARAH3 satellite product (2005–present) with ERA5 fallback. Hourly timeseries + annual summaries.

Geographic data on ~790,000 incentivized renewable energy plants in Italy with GPS coordinates, capacity, and commissioning date.

Cadastral ownership data accessed via the visura-api service for parcel owner identification.

The regional screening follows the GMSfT v5 (Ground-Mount Screening Flow Toolchain) three-step process:

Step 1 — Exclusion subtraction: Subtract all hard exclusion zones from the Lazio territory (Natura 2000, EUAP, Ramsar, flood R3/R4, PTPR forests/waters/archaeology, coastal/lake buffers).
Step 2 — Eligible area identification: Identify land categories eligible for ground-mount PV (CUS 2016 industrial/brownfield CLC 121–142, motorway 300m buffer, railway perimeters).
Step 3 — Agricultural exceptions: Apply Art. 11-bis c.2 derogation for agricultural land within infrastructure buffers (motorway 300m, railway perimeters on CLC 2xx land).

The result is a set of eligible polygons with area (ha) and estimated capacity (MWp) at GCR=0.35.

The cost-benefit analysis uses parametric benchmarks calibrated to the Lazio market (2025–2026):