Solar Calculator Italy 2026

Italian rooftop solar after the end of Scambio sul Posto

Italy's economics changed decisively in 2025: the Scambio sul Posto (SSP) net-billing scheme closed to new systems from 29 May 2025, with final applications accepted only until late September 2025. New residential systems now sell surplus through the GSE's Ritiro Dedicato (RID), which pays roughly the zonal wholesale price — about €0.10–0.11/kWh recently, with a guaranteed minimum (prezzo minimo garantito) near €0.05/kWh for small plants. Existing SSP contracts continue until they expire. Because this framework is new, verify the current mechanism with the GSE (gse.it) and ARERA before you commit.

Self-consumption is king

With household tariffs around €0.25–0.35/kWh and exports worth only about €0.10, every kWh you use directly is worth roughly three times one you sell. That inverts the old SSP logic: size the system to your daytime load rather than your roof. The calculator's self-use slider captures this — start near 50% if you can shift appliances to daylight, and use the system size calculator to avoid overbuilding. Batteries and membership in a comunità energetica rinnovabile (CER), which earns incentives on shared energy, are the two main ways to lift the value of surplus; the battery bank calculator helps size storage.

The 50% detrazione survives 2026 — with a catch

The 2026 budget law confirmed the bonus casa renovation deduction: 50% of costs (up to €96,000) back through Irpef over ten equal annual instalments for your prima casa, but only 36% for second homes. A €8,400 system on a main residence therefore returns €4,200 in tax relief, €420 per year for a decade — provided you have enough Irpef liability to absorb it. VAT on residential installs is a reduced 10%. Rates have been revised repeatedly in recent budgets, so confirm the current percentage with the Agenzia delle Entrate before signing.

Worked example: 4 kW near Rome

At 4.0 kWh per kW per day, a 4 kW system produces about 5,840 kWh/year. Self-consuming 50% at €0.30/kWh saves €876; selling the rest via RID at €0.10 adds €292 — about €1,168/year. Italian installs cost more than Spain's, typically €1.80–2.50/W; at €2.10/W the system is €8,400, or an effective €4,200 after the prima-casa deduction. Effective payback lands around 4–7 years depending on how you count the ten-year tax flow. Run your own tariff through the savings calculator, check production for your region with the solar output calculator, and compare with Germany's feed-in model in the Germany solar calculator.

• RID income above the personal threshold may need declaring; PMG values are updated by ARERA.
• Milan gets about 3.7 kWh per kW per day and Palermo about 4.2.

Solar calculators for other countries

Localized subsidy and tariff math for more markets:

Frequently asked questions

No. SSP closed to new systems from 29 May 2025, with the final application window ending in September 2025. Existing contracts run until their natural expiry (max 15 years). New systems sell surplus via the GSE's Ritiro Dedicato or join a renewable energy community (CER). Check gse.it for the current rules.

Yes, the 2026 budget law kept the bonus casa at 50% (max spend 96,000 euro) for a main residence, recovered through Irpef over 10 years. Second homes get 36%. You need sufficient annual Irpef to use each instalment, so confirm your position with the Agenzia delle Entrate or an accountant.

RID pays the hourly zonal market price, recently around 0.10-0.11 euro/kWh on average, and small plants can opt for the prezzo minimo garantito floor of roughly 0.05 euro/kWh. Prices move with the wholesale market, so treat the export rate in this calculator as an editable estimate.

Typical turnkey residential prices are 1.80-2.50 euro per watt, so a 4 kW system costs about 7,200-10,000 euro before incentives, with 10% VAT. After the 50% prima-casa detrazione the effective cost halves, though the benefit arrives over ten annual tax instalments.

About 12 kWh a day or 4,381 kWh a year on average, from about 7.5 a day in December to 15.7 a day in July, according to PVGIS data for panels at the best fixed angle. Shading, dust and orientation change the result.