To estimate the Net Debt / EBITDA ratio for Naturgy Energy Group S.A. for the year 2022 (ending 2022-12-31, which corresponds to the 2023-01-01 balance sheet figures provided), we follow the S&P methodology for corporate ratings.

**1. EBITDA Calculation:**
The facts provide "Beneficio Bruto De Explotacion Ebitda" (EBITDA) for the period 2022-01-01 to 2023-01-01 as 4,954,000,000 EUR.

**2. Net Debt Calculation:**
According to standard S&P methodology, Net Debt = (Long-term borrowings + Short-term borrowings + Current portion of long-term debt) - (Cash and Cash Equivalents).
*   Long-term borrowings (2023-01-01): 12,689,000,000 EUR
*   Current borrowings (2023-01-01): 2,110,000,000 EUR
*   Total Debt = 12,689,000,000 + 2,110,000,000 = 14,799,000,000 EUR
*   Cash and Cash Equivalents (2023-01-01): 3,985,000,000 EUR
*   Net Debt = 14,799,000,000 - 3,985,000,000 = 10,814,000,000 EUR

*(Note: Lease liabilities are typically excluded from this specific debt calculation if following a simplified Net Debt approach; however, if included as per some S&P adjustments, the debt would increase. Based on the standard provided financial line items: 10,814,000,000 EUR)*

**3. Ratio Calculation:**
Net Debt / EBITDA = 10,814,000,000 / 4,954,000,000 ≈ 2.18288

Rounding to a standard decimal representation:
10,814 / 4,954 ≈ 2.18288

<answer>2.18</answer>