To calculate the S&P-adjusted FFO-to-debt ratio for ERG S.p.A. for 2022, we follow the prescribed workflow:

**Step 1: Identify Industry**
ERG S.p.A. is primarily focused on renewable energy generation (wind, solar, hydroelectric). This aligns with the "Unregulated Power and Gas" industry.

**Step 2: Estimate Adjusted EBITDA**
Reported EBITDA is provided: "Profit Loss From Operating Activities Before Interest Taxes Depreciation And Amortisation Expense" = 499,430,000 EUR.
Standard S&P adjustments include adding back operating lease interest (often captured within the lease liability adjustment) and adjusting for non-recurring items. The report shows "Impairment Loss Reversal" of 43,185,000 EUR (gain). We adjust the reported EBITDA for this non-recurring/non-cash gain.
Adjusted_EBITDA = 499,430,000 - 43,185,000 = 456,245,000 EUR.

**Step 3: Estimate FFO**
FFO = Adjusted_EBITDA - cash_interest - cash_taxes
- Cash Interest: Finance costs are 112,195,000 EUR. Finance income is 75,622,000 EUR. Net interest expense is 36,573,000 EUR.
- Cash Taxes: The prompt provides "Income Taxes Paid Classified As Operating Activities" = 91,854,000 EUR.
FFO = 456,245,000 - 36,573,000 - 91,854,000 = 327,818,000 EUR.

**Step 4: Estimate Adjusted Debt**
Adjusted_Debt = (Total Debt - Eligible Cash)
- Total Debt = Noncurrent Financial Liabilities (Other Noncurrent Financial Liabilities 1,751,255,000 + Noncurrent Lease Liabilities 150,955,000) + Current Financial Liabilities (Other Current Financial Liabilities 389,716,000 + Current Lease Liabilities 6,362,000 + Current Financial Liabilities at FVTPL 76,644,000).
- Total Debt = 1,751,255,000 + 150,955,000 + 389,716,000 + 6,362,000 + 76,644,000 = 2,374,932,000 EUR.
- Eligible Cash = Cash and Cash Equivalents = 392,811,000 EUR.
Adjusted_Debt = 2,374,932,000 - 392,811,000 = 1,982,121,000 EUR.

**Step 5: Calculate FFO / Adjusted_Debt Ratio**
Ratio = 327,818,000 / 1,982,121,000 = 0.165387...

Rounding to four decimal places: 0.1654.

<answer>0.1654</answer>