To estimate the Net Debt / EBITDA ratio for 2022 based on the S&P methodology, we need to calculate the company's Net Debt and its EBITDA for the period ending 2022-12-31 (which corresponds to the start of 2023 in the provided facts).

**1. Calculate Net Debt**
According to S&P methodology, Net Debt is generally calculated as:
Net Debt = Total Financial Debt - Cash and Cash Equivalents

*   **Total Financial Debt**: This includes both current and non-current borrowings and other financial liabilities.
    *   Long-term Borrowings (2023-01-01): 15,782,604,000 EUR
    *   Current Borrowings and Current Portion of Noncurrent Borrowings (2023-01-01): 4,239,869,000 EUR
    *   Other Noncurrent Financial Liabilities (2023-01-01): 5,159,496,000 EUR
    *   Other Current Financial Liabilities (2023-01-01): 3,600,893,000 EUR
    *   *Total Financial Debt* = 15,782,604,000 + 4,239,869,000 + 5,159,496,000 + 3,600,893,000 = 28,782,862,000 EUR

*   **Cash and Cash Equivalents** (2023-01-01): 4,900,205,000 EUR

*   **Net Debt** = 28,782,862,000 - 4,900,205,000 = 23,882,657,000 EUR

**2. Calculate EBITDA**
S&P defines EBITDA broadly as the operating profit before depreciation, amortization, and impairment. The report provides a specific line item for "Profit Loss Before Provisions Amortisation And Impairment Financial Income And Financial Expenses Income Tax Expense And Extraordinary Contribution To The Energy Sector CESE" which serves as the EBITDA proxy used by the company. 
*   **EBITDA** (2022-01-01 to 2023-01-01): 4,523,539,000 EUR

**3. Calculate the Ratio**
*   Net Debt / EBITDA = 23,882,657,000 / 4,523,539,000 ≈ 5.280

<answer>5.280</answer>