To estimate the S&P-adjusted FFO-to-debt ratio for Terna S.p.A. for the fiscal year ended December 31, 2022, we follow the S&P Global Ratings Corporate Methodology, applying specific guidelines for Regulated Utilities.

**Step 1: Estimate Adjusted FFO (Funds From Operations)**
S&P bases FFO on operating cash flows before working capital changes, minus cash interest paid and cash taxes paid.
- **Base FFO:** We can calculate this using the reported Cash Flows from Operations (OCF) and adjusting for working capital changes, or directly from the pre-working capital operating cash flow.
  "Cash Flows From Used In Operations Before Changes In Working Capital" = 2,072.7m EUR.
  This figure is *before* interest and taxes. To get the standard FFO base, we add cash interest received and subtract cash interest paid and cash taxes paid:
  Base FFO = 2,072.7m + 64.2m (Interest Received) - 154.8m (Interest Paid) - 380.1m (Taxes Paid) = **1,602.0m EUR**. 
  *(This exactly matches Reported OCF of 2,323.7m EUR minus total Working Capital changes of 721.7m EUR).*

- **Capitalized Interest Adjustment:** S&P treats capitalized interest as a current period cash interest expense, reducing FFO.
  Capitalized Interest = 24.8m EUR.

- **Hybrid Bond Coupon Adjustment:** Terna issued 989.0m EUR in perpetual hybrid bonds in 2022. S&P treats these corporate hybrids as 50% equity and 50% debt. Therefore, 50% of the hybrid coupon is treated as a cash interest expense.
  Coupon Payable on Hybrid Bonds = 21.1m EUR.
  50% of Hybrid Coupon = 10.55m EUR.

*Adjusted FFO* = 1,602.0m - 24.8m - 10.55m = **1,566.65m EUR**.

**Step 2: Estimate Adjusted Debt**
Adjusted Debt includes reported gross borrowings, plus S&P standard additions (such as pension deficits and the debt-portion of hybrid bonds), minus eligible cash and cash equivalents. S&P typically excludes the fair value of derivatives from debt.
- **Reported Borrowings:** 
  Long-term Borrowings = 8,416.7m EUR
  Current Portion of Long-term Borrowings = 1,909.3m EUR
  Short-term Borrowings = 444.1m EUR
  *Total Borrowings* = 10,770.1m EUR.

- **Hybrid Bonds (Debt Portion):** 
  50% of 989.0m EUR Hybrid Bond = 494.5m EUR.

- **Pension Deficit:** 
  "Noncurrent Provisions For Employee Benefits" = 48.4m EUR.

- **Eligible Cash:** 
  "Cash and Cash Equivalents" = 2,155.1m EUR.
  *(Note: "Current Financial Assets" of 255.3m EUR are excluded as they predominantly represent the fair value of cash flow hedge derivatives).*

*Adjusted Debt* = 10,770.1m + 494.5m + 48.4m - 2,155.1m = **9,157.9m EUR**.

**Step 3: Calculate the Ratio**
FFO / Adjusted Debt = 1,566.65m EUR / 9,157.9m EUR = 0.1710708...

<answer>0.1711</answer>