**Step 1: Identify the relevant industry**
Based on the description of the entity's operations ("transmission system operator") and the provided S&P methodology, TenneT Holding B.V. falls under the **Regulated Utilities** sector. The methodology does not prescribe any industry-specific modifications to the baseline debt or EBITDA formulas (unlike the adjustments for purchased power or securitized debt mentioned in the text, which are inapplicable here).

**Step 2: Estimate Adjusted_Debt**
We use the baseline formula: `Adjusted_Debt = (reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items) - eligible_cash`

- **Reported Debt:** We take the sum of Long-term Borrowings and Short-term Borrowings, plus Current Bank Overdrafts and Other Current Financial Liabilities (if debt-like).
  Long-term Borrowings (2022-01-01) = 12,366,000,000 EUR
  Short-term Borrowings (2022-01-01) = 1,339,000,000 EUR
  Current Bank Overdrafts (2022-01-01) = 64,000,000 EUR
  Other Current Financial Liabilities (2022-01-01) = 281,000,000 EUR (Assumed debt-like based on typical S&P adjustments)
  *Total Reported Debt* = 12,366 + 1,339 + 64 + 281 = 14,050,000,000 EUR
  
- **Leases:** We add the principal value of lease liabilities as a debt-like item.
  Noncurrent Lease Liabilities (2022-01-01) = 235,000,000 EUR
  Current Lease Liabilities (2022-01-01) = 169,000,000 EUR
  *Total Leases* = 404,000,000 EUR

- **Pension Deficit:** Calculated as Net Defined Benefit Liability. 
  Noncurrent Recognised Liabilities DB Plan (2022-01-01) = 351,000,000 EUR
  (No DB Assets listed, so deficit = 351,000,000 EUR)
  *Pension Deficit* = 351,000,000 EUR

- **Hybrid Capital:** S&P generally treats hybrid capital as 50% debt and 50% equity.
  Hybrid Capital (2022-01-01) = 2,125,000,000 EUR
  *Hybrid Debt Portion* = 2,125,000,000 * 50% = 1,062,500,000 EUR

- **Guarantees / Other debt-like items:** 0 EUR (None identified from facts)

- **Eligible Cash:** S&P deducts cash that is not needed for working capital or day-to-day operations. We use Cash And Cash Equivalents.
  Cash And Cash Equivalents (2022-01-01) = 3,204,000,000 EUR

*Calculation:*
Adjusted_Debt = (14,050,000,000 + 404,000,000 + 351,000,000 + 1,062,500,000) - 3,204,000,000
Adjusted_Debt = 15,867,500,000 - 3,204,000,000 = 12,663,500,000 EUR

**Step 3: Estimate Adjusted_EBITDA**
We use the baseline formula: `Adjusted_EBITDA = EBITDA + adjustment_leases + nonrecurring_losses - nonrecurring_gains ± pension_adjustments ± joint_venture_proportional_EBITDA ± other_normalization_adjustments`

- **EBITDA:** Profit Loss from Operating Activities + Depreciation And Amortisation Expense
  Profit Loss from Operating Activities (2022) = -976,000,000 EUR
  Depreciation And Amortisation Expense (2022) = 1,233,000,000 EUR
  *Reported EBITDA* = -976,000,000 + 1,233,000,000 = 257,000,000 EUR

- **Adjustment for Leases:** We add back the lease interest expense implied in the operating profit to neutralize the rent expense deduction. We estimate lease interest as the Lease Liability * 3% (standard S&P approximation).
  Lease Liability (Noncurrent 235m + Current 169m) = 404,000,000 EUR
  *Lease Interest Adjustment* = 404,000,000 * 3% = 12,120,000 EUR

- **Pension Adjustments:** Add back reported pension cost and subtract estimated service cost. Based on the change in the DB Liability (351m -> 174m) and OCI adjustments, estimated service cost is roughly 74,000,000 EUR. S&P adjustment entails adding back the net pension expense in EBITDA and deducting the service cost. (Net pension expense is typically the change in liability minus actuarial gains and employer contributions; for simplicity, the net add-back of pension interest/cost vs service cost approximates a 0 adjustment on the EBITDA line for defined benefit plans under IFRS remeasurement rules). We will use 0 EUR.

- **Nonrecurring items:** "Other Gains Losses" is -38,000,000 EUR (a loss). Under S&P methodology, we add back nonrecurring losses. 
  *Nonrecurring items adjustment* = 38,000,000 EUR

- **Joint Venture Proportional EBITDA:** TenneT reports "Share Of Profit Loss Of Associates And Joint Ventures" of 120,000,000 EUR. We estimate the proportional EBITDA margin for the JVs at 50% (implied EV/EBITDA of 6x), meaning EBITDA is roughly 2x the net income share.
  *JV Proportional EBITDA Adjustment* = 120,000,000 * 2 = 240,000,000 EUR

- **Other Normalization Adjustments:** 0 EUR

*Calculation:*
Adjusted_EBITDA = 257,000,000 + 12,120,000 + 38,000,000 + 240,000,000
Adjusted_EBITDA = 547,120,000 EUR

**Step 4: Calculate Adjusted_Debt / Adjusted_EBITDA**
Ratio = 12,663,500,000 / 547,120,000
Ratio = 23.1483...

Rounding to two decimal places, we get 23.15.

<answer>23.15</answer>