With the advent of rapid advancements in the energy storage technologies and in harnessing the renewable resources, a variety of mix of “Problem formulation techniques” and “Solution methodologies” have emerged for scheduling the power generation in Grid integrated environment. Multiple constituent attributes and their combinations thereof define the nature of Unit Commitment problem formulation in a complex way. An attempt has been made in this paper to consolidate the available research efforts, spanning over about past two decades, so as to unravel the rising complexities in developing the unit commitment formulation in this rapidly evolving green energy era. The prevailing unit commitment models have been thoroughly reviewed on the bases of deployment of different combinations of features like objective functions, constraints, optimization techniques, types of renewable generation, and types of storage. This review work presents, in a categorized manner, the viewpoints on problem formulation as well as on the solution methodologies. Further, a novel Unit Commitment model has been proposed by the authors wherein modeling details of each of them have been presented in a conscientious manner. The proposed model is unique as the battery charge/ discharge decision making has been included as a co-optimization problem with the existing Unit Commitment problem. The superiority of the proposed model has also been reported. © 2021 John Wiley & Sons Ltd