Ready or not: From technology-level readiness to system-level readiness

The increasing penetration of renewable energy sources has heightened interest in integrated energy systems, in which multiple energy carriers and conversion technologies operate in a coordinated manner. Despite this trend, current development practices continue to focus primarily on the maturity of individual technologies. In contrast, the maturity of their interactions remains insufficiently assessed. Existing methods for evaluating technology, integration, and system maturity have been adopted unevenly in the energy domain, and reliable information on integration performance is rarely available. This paper presents a cross-sectoral review of maturity assessment approaches and extracts practices that can be transferred to integrated energy systems. Building on the review, the paper proposes a structured methodology for assessing the maturity of integrated energy systems based on a tropical algebra formulation designed to preserve key properties of readiness assessment. The framework combines: (i) systematic system identification using a hybrid GAMES–Design Structure Matrix model, (ii) TRL scoring, (iii) an IRL assessment process based on explicit interface-level decision criteria, (iv) an SRL formulation grounded in tropical algebra to avoid readiness reversal and system maturity overestimation, and (v) provides targeted design and maturity recommendations to system designers and innovation providers. A case study of a potential offshore energy project demonstrates the whole procedure. It illustrates how the methodology identifies integration bottlenecks, evaluates alternative technology choices, and captures changes in integration maturity resulting from operational decisions.