Reasoning:

REDEIA is a regulated infrastructure/utility group with large, stable asset base and strong operating cash flow, which generally makes it a good candidate for some hybrid bond financing. Hybrids can be useful for utilities because rating agencies often grant partial equity credit, helping preserve credit metrics while financing long-duration assets.

Key considerations:

- Leverage is meaningful but not extreme. At year-end 2022, financial liabilities were about €7.25bn, while cash and cash equivalents were about €0.79bn, implying substantial net debt. However, the company also generated strong operating cash flow of about €1.57bn.
- Equity strengthened materially in 2022, rising from about €3.69bn to €4.89bn, helped by owner transactions and comprehensive income. This reduces the need to rely heavily on hybrids purely to support the balance sheet.
- Earnings and cash flows are stable but not rapidly growing. Profit attributable to owners declined slightly from €681m to €665m, while operating profit also fell from €992m to €962m. The business can support debt, but higher interest rates in 2022 make excessive hybrid issuance less attractive.
- Interest rates rose sharply in 2022. The 5Y swap average moved from negative in 2021 to 1.726% in 2022, and corporate bond yields also increased. Hybrid bonds would likely be meaningfully more expensive than senior debt, especially given the sub-senior spread premium.
- The company already has significant conventional debt and regulated cash-flow visibility, so hybrids are useful as a supplementary tool, not as the dominant source of capital.
- A 0% allocation would ignore the strategic benefits of hybrids for a capital-intensive utility. But 50% or more would be too aggressive given the higher coupon cost, call/refinancing risk, and the fact that equity and operating cash flow are already solid.

Therefore, the most balanced choice is a moderate reliance on hybrid bonds: enough to improve financial flexibility and rating-equity treatment, but not so much that the company overpays for capital or complicates its capital structure.

<answer>25%</answer>