To estimate the Net Debt to EBITDA ratio for HERA S.P.A. in 2022 based on the S&P Global Ratings methodology, we calculate the S&P Adjusted EBITDA and S&P Adjusted Net Debt from the provided financials.

**1. S&P Adjusted EBITDA:**
S&P computes EBITDA by taking operating revenues minus operating expenses (excluding depreciation, amortization, and non-cash provisions), and then adding back cash dividends received from equity investments (associates/joint ventures) instead of their share of profit. 

*   **Operating Revenues:** Revenue (20,082.0m) + Other Revenue (548.2m) + Capitalised Work (82.5m) = 20,712.7m EUR
*   **Operating Expenses:** Raw Materials (16,730.0m) + Services (2,105.8m) + Employee Benefits (601.1m) + Other Expense (74.9m) = 19,511.8m EUR
*   **Base EBITDA (MOL):** 20,712.7m - 19,511.8m = 1,200.9m EUR 
*(Note: This matches EBIT of 533.8m + D&A and Provisions of 667.1m)*
*   **Add:** Dividends Received Classified As Operating Activities = 13.4m EUR
*   **S&P Adjusted EBITDA** = 1,200.9m + 13.4m = **1,214.3m EUR**

**2. S&P Adjusted Net Debt:**
S&P includes standard reported financial debt, adds lease liabilities and unfunded pension obligations (post-employment benefits), and subtracts accessible cash and liquid short-term investments.

*   **Financial Debt:** Noncurrent Financial Liabilities (5,689.9m) + Current Financial Liabilities (650.1m) = 6,340.0m EUR
*   **Lease Liabilities:** Noncurrent (55.1m) + Current (21.3m) = 76.4m EUR
*   **Pension Obligations:** Noncurrent Provisions For Employee Benefits = 92.0m EUR
*   *Gross Adjusted Debt* = 6,340.0m + 76.4m + 92.0m = 6,508.4m EUR
*   **Less Cash & Liquid Investments:** Cash And Cash Equivalents (1,942.4m) + Current Financial Assets (77.7m) = 2,020.1m EUR
*   **S&P Adjusted Net Debt** = 6,508.4m - 2,020.1m = **4,488.3m EUR**

**3. Net Debt / EBITDA Ratio Calculation:**
Net Debt / EBITDA = 4,488.3m / 1,214.3m = 3.696x

<answer>3.7</answer>