Light-fidelity (Li-Fi) communication systems have gained increased concerns as new and alternative paradigm for wireless communications. Through the increased applications of light emitting diode (LED) lamps for lighting in indoor and outdoor applications, industrial and academic interests have been risen towards adding communication functionality to the standard light emitting diode lamp illumination functionality in light-fidelity systems. As being the same source for lighting and communication, extra power losses and stresses are imposed on the light emitting diode lamp and its power electronic drivers to perform the dual functionalities. Therefore, proper light emitting diode lamp driver design and control systems are required. This paper reviews the different architectures of light-fidelity communication systems and develops a powerful systematic approach for assessing the energy efficiency and the communication system performance metrics for light-fidelity systems. Various light-fidelity structures, communication modulators, power converters, and communication modulation methods are considered based on the mathematical modelling. Simulation results show that energy efficiency and communication system performance are largely affected by system architectures, components, and communication modulators. The obtained results show that the proposed method represents a systematic approach for calculating the energy efficiency and power losses for various elements in light-fidelity systems. Additionally, the calculated energy efficiency with adding the communication functionality is lower than the traditional illumination of the lamps. The type of modulation technique, type of modulator, modulation index value, and forward lamp current have substantial effects on the calculated energy efficiency.