Reasoning:

A2A is a regulated/utility-like Italian energy group with large capital needs and a material balance sheet expansion in 2022. Hybrid bonds can be useful for such issuers because S&P typically grants partial equity credit, improving credit metrics without issuing common equity. However, the decision should weigh leverage, interest-rate environment, cash generation, and the marginal cost of hybrid capital.

Key considerations:

- Leverage and capital structure: liabilities rose to €16.9bn from €13.69bn, while equity was €4.47bn. Financial liabilities increased materially, especially noncurrent financial liabilities, from €4.32bn to €5.87bn. This supports some use of hybrids to strengthen adjusted capital.
- Equity base: reported equity increased only modestly, from €4.30bn to €4.47bn, despite asset growth from €18.01bn to €21.37bn. Hybrid issuance could help preserve rating metrics.
- Profitability and cash flow: EBITDA increased slightly to €1.505bn, and operating cash flow was positive at €1.26bn. Free cash flow turned positive at €118m, but only modestly after significant investment needs. This suggests hybrids are useful, but not necessarily to the maximum.
- Market conditions: 2022 rates rose sharply. The 5Y swap average moved from negative levels to 1.726%, and 10Y to 1.927%. Corporate bond yields and subordinated/hybrid spreads also increased. This makes hybrid capital materially more expensive than in 2020–2021.
- Rating-cap logic: S&P’s 15% adjusted-capital cap is a ceiling, not an automatic target. Given the high-rate environment and the company’s still-positive cash generation, using the full cap would likely be too aggressive and costly.
- Strategic fit: as a capital-intensive utility, A2A should maintain access to hybrid capital and use it meaningfully, especially to support acquisitions, capex, and rating resilience. But because 2022 funding costs are elevated, a moderate-to-high utilization below the full cap is more appropriate.

Overall, the company should use hybrids substantially, but not fully up to S&P’s maximum cap. A 75% utilization of the cap best balances rating support and cost discipline.

<answer>75%</answer>