To estimate the Funds From Operations (FFO) to Net Debt ratio based on Standard & Poor's (S&P) methodology, we must first calculate FFO and S&P Adjusted Net Debt using the provided financial facts.

**1. Funds From Operations (FFO)**
S&P FFO is generally calculated as Cash Flow from Operating Activities adjusted for changes in working capital (i.e., we remove the cash flow impact of working capital fluctuations to see the normalized underlying cash generation).

- Cash Flows From Operating Activities: 3,777,785,000 EUR
- Changes in Working Capital (CWC) components provided:
  - Adjustments for Decrease in Trade and Other Receivables: 405,817,000 EUR
  - Adjustments for Increase in Trade and Other Payables: 766,260,000 EUR
  - Changes in Working Capital to Personnel: -142,137,000 EUR
  - Changes in Working Capital for Regulatory Assets: 502,859,000 EUR
  Total CWC = 405,817,000 + 766,260,000 - 142,137,000 + 502,859,000 = 1,532,799,000 EUR (This represents a cash inflow).

Subtracting the CWC from Operating Cash Flow gives us the cash flow before working capital changes:
FFO = 3,777,785,000 - 1,532,799,000 = 2,244,986,000 EUR.

**2. S&P Adjusted Net Debt**
S&P adjusts reported debt to include debt-like obligations such as underfunded pensions, lease liabilities, and tax equity financings, and subtracts accessible cash.
- Long-term Borrowings: 15,782,604,000 EUR
- Current Borrowings (including current portion of long-term debt): 4,239,869,000 EUR
- Institutional Partnerships in North America (S&P treats tax equity financing as debt): 2,212,162,000 EUR
- Noncurrent Provisions for Employee Benefits (Pensions): 644,299,000 EUR
- Current Provisions for Employee Benefits (Pensions): 126,767,000 EUR
*Gross Adjusted Debt* = 15,782,604,000 + 4,239,869,000 + 2,212,162,000 + 644,299,000 + 126,767,000 = 23,005,701,000 EUR.

We then deduct available liquidity:
- Cash and Cash Equivalents: 4,900,205,000 EUR

*S&P Adjusted Net Debt* = 23,005,701,000 - 4,900,205,000 = 18,105,496,000 EUR.

*(Note: Depending on exact analyst adjustments for items like full asset retirement obligations net of tax, this debt figure can slightly widen, but standard adjustments hold at this core level).*

**3. FFO / Net Debt Ratio**
FFO / Net Debt = 2,244,986,000 EUR / 18,105,496,000 EUR ≈ 0.12399 (or 12.4%)

<answer>0.124</answer>