This report establishes a strategy for modeling, simulation, and control of candidate hybrid energy systems. Modeling, simulation, and control are necessary to design, evaluate, and optimize the systems' technical and economic performance. This report first establishes modeling requirements to analyze candidate hybrid systems (a strict definition of "hybrid system" will be also provided). Modeling fidelity levels are based on the temporal scale, real and synthetic data availability or needs, solution accuracy, and output parameters needed to evaluate case-specific figures of merit (FOMs). The associated computational and co-simulation resources needed are established, including physical models when needed, code assembly and integrated solutions platforms, mathematical solvers, and data processing. This report first describes the FOMs, systems requirements, and constraints necessary to characterize the grid and hybrid system behaviors and market interactions. Grid reliability assessment metrics and effective cost of energy (ECE), as opposed to the standard levelized cost of electricity (LCOE), are introduced as technical and economic indices for integrated energy system evaluations. Financial assessment methods are subsequently introduced for evaluating nontraditional, hybrid energy systems. Algorithms for coupled and iterative evaluation of the technical and economic performance are subsequently discussed.This report further defines modeling objectives, computational tools, solution approaches, and real-time data collection and processing (in some cases using real test units) that will be required to model, control, co-simulate, and optimize:(1) energy system's components (e.g., power generation unit, chemical process, electricity management unit), (2) system domains (e.g., thermal, electrical or chemical energy generation, conversion, and transport), and (3) system control modules. Controlling and co-simulating complex, tightly coupled, dynamic energy systems requires multiple controls and simulation tools, potentially developed in several programing languages and resolved on separate time scales. Whereas further investigation and development of hybrid concepts will provide a more complete understanding of the joint computational and physical modeling and control needs, this report highlights areas where control and co-simulation capabilities are warranted. The current development status, quality assurance, availability, and maintainability of control and simulation tools available for hybrid systems modeling are presented. Existing gaps in the modeling, simulation, and control toolsets and development needs are subsequently discussed. This work will feed into broader efforts to design, develop, and demonstrate hybrid energy systems.