To estimate the Funds From Operations (FFO) to Net Debt ratio for Acciona SA for the year 2022 based on S&P methodology, we proceed with the standard S&P definitions:

**1. Calculate Funds From Operations (FFO):**
S&P generally calculates FFO by taking the reported Net Cash Flow from Operating Activities (CFO) and adjusting it to strip out the transient cash effects of changes in working capital. 
* Reported Operating Cash Flow (CFO) = 1,648,000,000 EUR
* Change in Working Capital (cash inflow from decrease in working capital) = 135,000,000 EUR
To find the underlying FFO, we remove the working capital cash inflow from the CFO:
* FFO = CFO - Change in Working Capital
* FFO = 1,648,000,000 - 135,000,000 = 1,513,000,000 EUR

*(Note: This captures the S&P required items like net interest paid of 209m EUR, taxes paid of 215m EUR, and dividends received from equity associates of 89m EUR which are already accurately netted in the reported Operating Cash flows).*

**2. Calculate Net Debt:**
S&P typically assesses Net Debt as Total Debt minus accessible cash and short-term liquid investments. 
Total Debt includes long-term and short-term portions of bonds, bank borrowings, and lease liabilities.
* Non-current Bonds & Negotiable Securities = 3,101,000,000 EUR
* Current Bonds & Negotiable Securities = 1,139,000,000 EUR
* Non-current Loans = 2,624,000,000 EUR
* Current Loans = 553,000,000 EUR
* Non-current Lease Liabilities = 439,000,000 EUR
* Current Lease Liabilities = 72,000,000 EUR
**Total Debt** = 3,101 + 1,139 + 2,624 + 553 + 439 + 72 = 7,928,000,000 EUR

Next, we subtract cash and liquid short-term financial assets:
* Cash and Cash Equivalents = 2,360,000,000 EUR
* Current Financial Assets (Short-term liquid investments) = 315,000,000 EUR
**Net Debt** = 7,928,000,000 - 2,360,000,000 - 315,000,000 = 5,253,000,000 EUR

**3. Calculate FFO / Net Debt Ratio:**
* FFO / Net Debt = 1,513,000,000 EUR / 5,253,000,000 EUR = 0.28802... (or 28.8%)

<answer>0.288</answer>