To estimate the FFO / Net Debt ratio for REN - REDES ENERGÉTICAS NACIONAIS, SGPS, S.A. for the year 2022 based on S&P methodology, we need to calculate Funds From Operations (FFO) and Net Debt.

**1. Calculate Funds From Operations (FFO)**

According to S&P Global Ratings methodology, FFO is generally calculated as:
$$FFO = \text{Net Income} + \text{Depreciation and Amortization} + \text{Other Non-Cash Items} + \text{Changes in Working Capital (sometimes excluded in simplified definitions, but S&P often uses EBITDA-based or Net Income + D&A adjustments)}$$

A common standard definition for FFO in utility/infrastructure contexts (like S&P's criteria for regulated utilities) is:
$$FFO = \text{Net Income} + \text{Depreciation and Amortization} + \text{Deferred Taxes} + \text{Other Non-Cash Items}$$
*Note: S&P often adds back deferred taxes and non-cash working capital changes. However, a simpler and very common proxy used when detailed cash flow adjustments aren't fully broken out for "non-cash" specifics beyond D&A is: FFO = Net Income + Depreciation & Amortization.*

Let's look at the provided data for the period 2022-01-01 to 2023-01-01 (Fiscal Year 2022):
*   **Net Income (Profit Loss):** 111,771,000 EUR
*   **Depreciation and Amortisation Expense:** 249,276,000 EUR

There are other potential adjustments:
*   **Share of Profit/Loss of Associates:** 11,812,000 EUR (This is included in Net Income. If it's equity income not received in cash, it might be subtracted, but dividends received are often added back or treated separately. S&P usually starts with Net Income).
*   **Deferred Tax Expense:** We can derive the deferred tax component.
    *   Total Income Tax Expense: 54,263,000 EUR
    *   Change in Deferred Tax Assets: $69,803,000 - 96,673,000 = -26,870,000$ (Decrease in asset is a tax expense/add-back to cash flow).
    *   Change in Deferred Tax Liabilities: $115,064,000 - 107,569,000 = +7,495,000$ (Increase in liability is a tax benefit/add-back to cash flow).
    *   Net Deferred Tax Add-back = Decrease in DTA + Increase in DTL = $26,870,000 + 7,495,000 = 34,365,000$ EUR.
    *   Alternatively, Current Tax Paid was 77,970,000. Current Tax Expense isn't explicitly isolated, but Total Tax is 54,263,000. The difference between expense and paid/deferred movements can be complex.
    *   Standard S&P FFO definition often includes: Net Income + Depreciation & Amortization + Deferred Taxes + Other Non-Cash Items.

Let's use the robust definition:
$$FFO = \text{Net Income} + \text{Depreciation \& Amortization} + \text{Net Deferred Tax Expense/Benefit Adjustment}$$

However, a very common simplified S&P metric for "FFO" in public ratings reports is often just **Net Income + Depreciation & Amortization** if deferred taxes are volatile or if looking for a core operating cash flow proxy before working capital. Let's look at the Cash Flow from Operations (CFO) to see if it aligns.
CFO = 613,466,000 EUR.
CFO includes changes in working capital. FFO typically excludes changes in working capital.

Let's stick to the standard accounting-based FFO calculation often cited in S&P criteria for utilities:
$$FFO = \text{Net Income} + \text{Depreciation and Amortization} + \text{Deferred Income Taxes} + \text{Other Non-Cash Charges}$$

*   Net Income: 111,771,000
*   Depreciation & Amortization: 249,276,000
*   Deferred Taxes: The income tax expense is 54,263,000. The cash tax paid is 77,970,000. The difference is partly due to deferred taxes.
    *   Change in Net Deferred Tax Position:
        *   DTA 2021: 96,673,000 -> DTA 2022: 69,803,000. Change: -26,870,000 (Source of cash/reduction in asset).
        *   DTL 2021: 107,569,000 -> DTL 2022: 115,064,000. Change: +7,495,000 (Source of cash/increase in liability).
        *   Total Deferred Tax Add-back (non-cash tax expense included in NI but not paid, or vice versa): Actually, we add back the *deferred tax expense* included in NI.
        *   Total Tax Expense (54,263,000) = Current Tax Expense + Deferred Tax Expense.
        *   Current Tax Paid (77,970,000) approximates Current Tax Expense adjusted for current tax payable changes.
        *   Let's check Current Tax Payable: 2021: 26,644,000 Liability. 2022: 0 Liability.
        *   Current Tax Expense = Tax Paid + Change in Current Tax Liability = $77,970,000 + (0 - 26,644,000) = 51,326,000$.
        *   Deferred Tax Expense = Total Tax Expense - Current Tax Expense = $54,263,000 - 51,326,000 = 2,937,000$.
        *   So, we add back Deferred Tax Expense of 2,937,000.

*   Other Non-Cash Items:
    *   Share of profit of associates (Equity Method): 11,812,000. This is non-cash income included in Net Income. We should subtract it.
    *   Dividends received from associates/joint ventures are often added back in FFO if not in Net Income, but here dividends received (9,815,000 in P&L? No, "Revenue From Dividends" is 9,815,000. Wait, "Share of Profit... Equity Method" is 11,812,000. Usually, equity income is one line, dividends are another. If dividends are recorded as income, they are cash. If equity pick-up is recorded, it's non-cash.
    *   Let's assume the "Revenue From Dividends" is cash dividends received from financial assets (FVOCI), not associates. The "Share of Profit... Equity Method" is the non-cash pickup from associates.
    *   So, subtract Equity Income: -11,812,000.
    *   Add Dividends Received from Associates? S&P FFO often adds dividends received from unconsolidated subsidiaries/associates. The data shows "Dividends Received Classified As Investing Activities" = 21,551,000. This likely includes dividends from associates. If we subtracted the equity pickup (11.8M), we should add the cash dividends received from those associates. However, we don't know the exact split of the 21.5M.
    *   Let's look at "Revenue From Dividends" in P&L: 9,815,000. This is likely from the FVOCI assets (145M balance). These are cash dividends. They are already in Net Income. No adjustment needed.
    *   The Equity Pickup (11.8M) is in Net Income but is non-cash. Subtract it.
    *   Are there cash dividends from associates included in the 21.5M investing cash flow? Yes. Are they in Net Income? No, only the equity pickup is. So we should add the cash dividends received from associates.
    *   Estimate of dividends from associates: Often close to the equity pickup or determined by payout policy. Without specific breakdown, a conservative approach is to just subtract the non-cash equity income. Or, use the standard "Net Income + D&A" as a baseline and adjust.

Let's try a simpler S&P-aligned FFO calculation often used for quick estimation:
$$FFO = \text{Net Income} + \text{Depreciation \& Amortization}$$
$$FFO = 111,771,000 + 249,276,000 = 361,047,000 \text{ EUR}$$

Let's refine with Deferred Taxes and Equity Income:
$$FFO = 361,047,000 + 2,937,000 (\text{Def Tax}) - 11,812,000 (\text{Equity Income}) = 352,172,000 \text{ EUR}$$

Let's check if there are other significant non-cash items.
"Impairment Loss Reversal": 1,437,000 (Gain, so subtract from NI? No, it's included in NI. It's non-cash? Reversals are non-cash gains. Subtract it).
$$FFO = 352,172,000 - 1,437,000 = 350,735,000 \text{ EUR}$$

Let's consider "Changes in Other Provisions": -2,230,000. This is an expense/release? "Changes in Other Provisions" in P&L is -2,230,000. A negative expense is a gain (release of provision). This is non-cash gain. Subtract it.
$$FFO = 350,735,000 - 2,230,000 = 348,505,000 \text{ EUR}$$

This seems too detailed and prone to error without the full cash flow reconciliation.
S&P's standard definition for FFO in many utility reports is:
**FFO = Net Income + Depreciation & Amortization + Deferred Taxes + Other Non-Cash Items.**

Let's look at the Cash Flow from Operations (613,466,000) vs this FFO.
CFO = FFO - Increase in Working Capital + Other.
If FFO is ~350M and CFO is ~613M, the difference is ~260M. This would imply a massive decrease in working capital or other sources.
Looking at Working Capital:
Receivables Current: 448M -> 327M (Decrease of 121M, Source of Cash).
Inventories: 8.5M -> 5.1M (Decrease of 3.4M, Source).
Payables Current: 644M -> 885M (Increase of 241M, Source).
Net Working Capital Change Source = $121 + 3.4 + 241 \approx 365M$.
This aligns well. CFO (613M) is roughly FFO (350M) + WC Sources (365M) - Tax Paid differences/Other.
So, an FFO estimate of **~350,000,000 EUR** is reasonable.

Let's use a slightly more generous FFO often seen in ratings:
Some definitions add back "Interest Paid" (if calculating pre-interest FFO) but S&P FFO is post-interest.
S&P FFO = Net Income + D&A + Deferred Tax + Non-cash comp + ...
Let's stick with **350,735,000 EUR** as a refined estimate.
Or, to be safe and standard, many analysts just use **Net Income + D&A**.
$FFO = 111,771,000 + 249,276,000 = 361,047,000$ EUR.
Let's use **361,047,000 EUR** as the base FFO, as it's the most transparent calculation from the provided lines. Adjustments for equity income and deferred taxes are small relative to the total.

**2. Calculate Net Debt**

Net Debt = Total Debt - Cash and Cash Equivalents.

*   **Total Debt:**
    *   Long-term Borrowings (2023-01-01, i.e., end of 2022): 1,695,362,000 EUR
    *   Current Borrowings and Current Portion of Noncurrent Borrowings (2023-01-01): 638,944,000 EUR
    *   Total Gross Debt = $1,695,362,000 + 638,944,000 = 2,334,306,000$ EUR

    *Note: S&P may also include lease liabilities. The cash flow statement shows "Payments Of Lease Liabilities" and "Payments Of Lease Interests". The balance sheet doesn't explicitly list "Lease Liabilities" as a separate line item under Noncurrent or Current Liabilities, but they might be embedded in "Trade And Other Non Current Payables" or "Trade And Other Payables Current". However, without explicit breakdown, we usually stick to Interest-bearing Borrowings. Given the "Investment Grade" nature and infrastructure assets, leases might be material. But looking at the liabilities:
    Noncurrent Liabilities: 2,409,702,000.
    Components: Longterm Borrowings (1,695M) + Provisions Employee (64M) + Derivatives (73M) + Other Provisions (10M) + Trade/Other NonCurrent Payables (450M) + Deferred Tax (115M).
    Sum = $1695 + 64 + 73 + 10 + 450 + 115 = 2,407$M. Close to 2,409M.
    Current Liabilities: 2,524,360,000.
    Components: Current Borrowings (638M) + Trade/Other Payables Current (885M) + Current Tax (0) + Liability Gas Price (1,000M).
    Sum = $638 + 885 + 1000 = 2,523$M. Close to 2,524M.
    
    The "Liability Related To The Transitional Gas Price Stabilization Regime" is 1,000,000,000 EUR. Is this debt? It's a regulatory liability, not financial debt. S&P typically excludes regulatory liabilities from Net Debt unless they are interest-bearing and mandatory repayments akin to debt. This is likely a pass-through mechanism. We will exclude it from Net Debt.
    
    So, Gross Debt = 2,334,306,000 EUR.

*   **Cash and Cash Equivalents:**
    *   Cash And Cash Equivalents (2023-01-01): 365,292,000 EUR

*   **Net Debt:**
    $$Net Debt = 2,334,306,000 - 365,292,000 = 1,969,014,000 \text{ EUR}$$

**3. Calculate FFO / Net Debt Ratio**

Using FFO = 361,047,000 EUR (Net Income + D&A):
$$Ratio = \frac{361,047,000}{1,969,014,000} \approx 0.1833$$

Using Refined FFO = 350,735,000 EUR:
$$Ratio = \frac{350,735,000}{1,969,014,000} \approx 0.1781$$

S&P methodology often makes further adjustments to FFO (e.g., adding back preferred dividends, adjusting for pension costs).
Pension costs: "Noncurrent Provisions For Employee Benefits" decreased from 94M to 64M. "Employee Benefits Expense" is 58.5M. The cash paid was 76.2M. The difference is complex.
However, the "Net Income + D&A" proxy is the most standard starting point.

Let's double check if "Preference Shares" or "Minority Interest" affects the numerator.
"Profit Loss Attributable To Noncontrolling Interests" is 0.
So Net Income is fully attributable to parent.

Let's check if S&P adds back "Interest Expense" to FFO? No, FFO is after interest. Debt/FFO is the leverage ratio.

Is there any other debt?
"Noncurrent Derivative Financial Liabilities": 73,464,000. These are derivatives, not debt principal.
"Current Derivative Financial Assets": 236,000.

So Net Debt is ~1.97 Billion.
FFO is ~0.36 Billion.

Ratio $\approx 18.3\%$.

Let's consider if the "Liability Related To The Transitional Gas Price Stabilization Regime" should be treated as debt. It is a 1B EUR liability. If treated as debt, Net Debt increases by 1B (assuming no cash offset specific to it).
Net Debt would be ~2.97 Billion.
Ratio would be $361 / 2970 \approx 12.1\%$.
However, this liability is matched by an "Asset Related To The Transitional Gas Price Stabilization Regime" of 1B EUR.
Net Position on this item is 0.
S&P usually nets such regulatory assets/liabilities if they are pass-through. So excluding both is correct.

Therefore, the ratio is approximately 0.18.

Let's refine the FFO calculation one more time using the exact S&P definition components if possible.
S&P FFO = Net Income + Depreciation & Amortization + Deferred Taxes + Other Non-Cash Items.
Net Income: 111,771,000
D&A: 249,276,000
Deferred Taxes:
DTA Change: (69,803 - 96,673) = -26,870 (Add back)
DTL Change: (115,064 - 107,569) = +7,495 (Add back)
Total Deferred Tax Add-back: 34,365,000?
Wait, earlier I calculated Deferred Tax *Expense* as 2.9M.
The add-back in FFO is the *Deferred Tax Expense* included in Net Income.
If DTA decreases, it means we used up an asset, which is a tax expense (or reduction of benefit) that didn't use cash? No.
Change in DTA: Decrease in DTA is a source of cash (or rather, the expense was recognized previously, now reversing? Or we paid less tax than expense?).
Let's stick to the P&L Tax Expense vs Cash Tax Paid logic.
Tax Expense: 54,263,000.
Cash Tax Paid: 77,970,000.
The difference is -23,707,000.
This implies Cash Tax > Tax Expense.
So Deferred Tax was a *benefit* (negative expense) or we paid down prior liabilities.
Current Tax Liability decreased by 26,644,000.
So Current Tax Expense = Paid (77,970) - Decrease in Liability (26,644) = 51,326,000.
Deferred Tax Expense = Total (54,263) - Current (51,326) = 2,937,000.
So we add back 2,937,000.

Other Non-Cash:
Equity Income (Subtract): -11,812,000.
Impairment Reversal (Subtract): -1,437,000.
Provision Release (Subtract): -2,230,000.
Gain/Loss on Derivatives? "Noncurrent Derivative Financial Assets" increased significantly (19M to 80M). "Noncurrent Derivative Financial Liabilities" increased (23M to 73M).
The P&L has "Finance Income Cost" of -45,668,000 (Net Cost).
This includes interest and likely derivative marks-to-market.
S&P FFO usually excludes mark-to-market gains/losses on derivatives if they are not settled in cash? Or adds them back?
S&P typically adds back non-cash MTM losses and subtracts non-cash MTM gains.
Without the breakdown of Finance Costs into Interest vs MTM, it's hard to adjust precisely.
However, "Finance Costs" are 67,394,000. "Other Finance Income" is 11,911,000. "Revenue From Dividends" 9,815,000.
Net Finance Cost = $67,394 - 11,911 - 9,815 = 45,668$ (Matches "Finance Income Cost" -45,668).
Interest Paid (Financing) is 40,545,000.
Interest Paid (Operating)? No, classified as Financing.
So Cash Interest is ~40.5M.
Finance Cost P&L is 67.4M.
Difference ~27M. This could be non-cash interest (amortization of fees/discounts) or MTM losses on derivatives.
If it's non-cash interest, we add it back to FFO? No, FFO is after interest. But if the interest expense is non-cash, Net Income is lower by that amount. So we should add back non-cash interest expense.
If the 27M difference is non-cash, we add it back.
Let's assume half is non-cash? This is getting speculative.

Given the uncertainties, the "Net Income + D&A" metric is the most robust *standard* estimate for FFO in absence of a detailed reconciliation.
FFO = 361,047,000.
Net Debt = 1,969,014,000.
Ratio = 0.183.

Rounding to two decimal places: 0.18.

<answer>0.18</answer>