This article assesses the techno-economic feasibility of retrofitting an existing, real decentralised cogeneration project in Ukraine — the AVERGY project — to accept hydrogen–methane blends, as a planned second stage following the project's natural-gas-fired Stage 1 commissioning. The assessment synthesises the author's prior published technical research on hydrogen–methane blending limits in Ukrainian gas networks with project-specific retrofit cost data. Four hydrogen-content thresholds are identified from the technical literature — 5% (current regulatory cap), 13% (density compliance boundary), 19–20% (burner-modification threshold and Hydrogen Strategy target) — each implying a different equipment response. Applied to the AVERGY cogeneration unit, indicative Stage 2 retrofit investment is estimated at UAH 40,600,000, approximately 47% of the Stage 1 capital expenditure, allocated across fuel-system adaptation, metering upgrades, material-compatibility works and certification. Unlike Stage 1, for which verified cash-flow appraisal and investment-return indicators are available, Stage 2 is not evaluated as a conventional revenue-generating investment; instead, the article frames it through real-option and stranded-asset-risk mitigation logic, under which the retrofit preserves the asset's future compatibility with tightening hydrogen-blending mandates rather than generating additional metered revenue at current blend ratios. The findings provide a transferable cost-component framework and an options-based valuation logic for assessing hydrogen-readiness retrofits of existing gas-fired cogeneration assets in Ukraine.
