To assess the extent to which EDP, S.A. should utilize hybrid bonds, we evaluate its business and financial profile based on the 2022 annual report and S&P Global Ratings' methodologies for regulated utilities and unregulated power and gas:

1. **High Capex Intensity and Acquisitions**: 
   EDP demonstrates substantial ongoing investment needs to fund its energy transition and renewable energy build-out (via EDP Renováveis). In 2022, the company reported extensive cash outflows for investments, including €3.5 billion in property, plant, equipment, and intangible assets, alongside €1.54 billion to obtain control of subsidiaries or other businesses (e.g., the acquisition of Sunseap). This strongly aligns with the "high capex intensity OR large acquisition pipeline" criteria.

2. **Significant Leverage Pressure**:
   Because of aggressive organic capex and acquisitions, EDP generated massive cash outflows. Even though cash flow from operations was robust at €3.78 billion, total cash used in investing activities outpaced it at €3.23 billion (net), and when accounting for large dividend obligations (€953 million combined), it resulted in a free cash flow deficit requiring external funding. Consequently, current borrowings expanded dramatically from €1.52 billion in 2021 to €4.24 billion in 2022, and non-current financial liabilities surged.

3. **Capital Structure Optimization and Rating Preservation**:
   With approximately €33-35 billion in total adjusted capital (Total Equity of €13.8 billion + ~€20 billion in short and long-term borrowings), utilizing hybrid bonds provides significant capital structure optimization. The S&P methodology allows a 50% equity credit treatment for hybrid notes up to 15% of the total adjusted capital. For EDP, utilizing hybrids up to this optimal upper-mid threshold mitigates the pressure on its credit metrics caused by leverage accumulation, allowing the firm to protect its solid investment-grade rating without facing an imminent "material downgrade risk" that would dictate an absolute 15% cap. 

4. **Cost of Debt Considerations**:
   EDP reported €716 million in direct interest and similar costs of financial debt on a ~€20 billion gross debt base, yielding an approximate average cost of debt around 3.5%. With the Sub-Senior Delta for IG non-financials expanding in 2022 to an average of ~2.3%, the issuance of hybrid subordinated debt will undoubtedly be slightly more expensive than senior debt, but given the existing cost structure, it has only a marginal impact overall while providing invaluable equity treatment.

Given these factors—most notably the heavy capex, strategic acquisitions, and the necessity to optimize leverage to defend its investment-grade status—EDP comfortably falls into the tier justifying an 11.25% utilization of hybrid bonds relative to total adjusted capital.

<answer>11.25%</answer>