Consume better, integrate more renewables: a critical framework for assessing energy synergy

The combination of renewable energy and energy efficiency is often described as synergistic, although its benefits are evaluated using indicators and references that are not always equivalent. This article develops a critical framework for assessing that interaction through a targeted integrative review of verified scientific literature and technical documents, emphasizing recent publications. The synthesis compares mechanisms, analytical boundaries, operating conditions, and the scope of the evidence without estimating an aggregate effect or conducting a bibliometric analysis. The findings distinguish reduced energy per service, electricity supply substitution, temporal flexibility, and consumer responses. Based on this differentiation, the Integrated Energy Synergy Model (MISE, its Spanish acronym) is reformulated as a conceptual proposal connecting renewables, efficiency, enablers, optimization decisions, and sustainability outcomes. A comparison is proposed between a reference and standalone efficiency, standalone renewables, and joint implementation scenarios, maintaining service equivalence and assessment conditions. The framework identifies favorable, zero, or unfavorable interactions for each indicator and avoids interpreting reduced electricity purchases as automatic evidence of total savings. The discussion explains why consumption timing, rebound, financing, and implementation constraints condition benefits. It concludes that synergy should be treated as a testable hypothesis rather than an inherent attribute of technological combination. MISE requires empirical validation or calibrated simulations before local benefits can be estimated or specific configurations recommended.