Appendix 3 extends the quantitative methodology to renewable fuel technologies (Power-to-X). The objective is to develop a dataset that fully reflects both technical and economic aspects of technologies such as hydrogen, ammonia, and e-fuels.

As with storage technologies, all data are standardized in terms of units, base year, and economic assumptions, ensuring comparability across technologies and development stages. Parameters are developed for multiple time horizons, reflecting technological progress and cost reduction potential over time.

The quantitative description again focuses on technical/energy data and economic data. However, for renewable fuels, technical parameters extend beyond efficiency to include input requirements (electricity, water, CO₂), output production, and characteristics related to the full fuel value chain. This reflects the cross-sectoral nature of Power-to-X technologies.

A distinctive feature is the full value chain perspective, from electricity input to final fuel product. Therefore, quantitative parameters must capture overall system efficiency as well as losses at each conversion stage.

From an economic perspective, the methodology includes capital costs, O&M costs, and input feedstock costs. Assumptions regarding electricity prices, system scale, and deployment levels play a critical role in determining fuel production costs.

The appendix also establishes standard definitions to ensure consistent interpretation of concepts and indicators across the entire catalogue, which is particularly important for emerging technologies where terminology and calculation methods may not yet be fully standardized.