Based on the provided financial facts for REN - REDES ENERGÉTICAS NACIONAIS, SGPS, S.A. for the fiscal year ending December 31, 2022, and the S&P Global Ratings methodology for Regulated Utilities, the recommendation for hybrid bond issuance is **0% of total adjusted capital**. 

Here is the reasoning aligned with the guidelines:

1. **Low Refinancing and Funding Needs**: 
REN exhibits very strong cash generation capabilities. In 2022, the company's operating cash flow was approximately €613.5 million against capital expenditures (purchase of intangibles and property, plant & equipment) of roughly €207.8 million, demonstrating robust free cash flow generation. The company is organically deleveraging, having reduced its long-term borrowings from €2.39 billion in 2021 to €1.70 billion in 2022.

2. **No Need for Leverage Optimization**: 
The company's leverage metrics improved significantly throughout the year. Its EBITDA improved to roughly €489 million in 2022 (up from ~€461 million in 2021), and total borrowings decreased. This leads to a declining Net Debt to EBITDA ratio, removing any pressure to issue hybrid debt for the sake of preserving investment-grade ratings or stabilizing its leverage trajectory.

3. **No Extraordinary Capex Needs or Transformational M&A**: 
The company's footprint as a regulated utility in Portugal relies on predictable maintenance and system upgrade capex, fully covered by its operating cash flow. There are no signs of a large acquisition pipeline or transformational capex that would warrant the use of intermediate equity content instruments.

4. **Relative Cost of Debt**: 
REN's current effective cost of debt is very low (paying roughly €40.5 million in interest against over €2.3 billion in total debt). However, looking at the 2022 market data, interest rates have surged (5Y/10Y Swap curves jumping over 1.7%-1.9%). Moreover, the subordination premium (Sub-Sen Delta) ballooned to nearly 2.3% in 2022. Issuing a hybrid bond now would saddle the company with a steeply higher coupon compared to its current senior debt cost without providing a necessary credit benefit.

5. **Current Capital Structure**: 
A review of the company's equity components shows no existing hybrid capital or subordinated debt recorded as equity. With strong organic metrics, introducing an expensive hybrid layer to the capital structure is entirely unnecessary.

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