This review explores the key components of crop production and energy consumption in indoor farming, where it usually consists of systems such as LED lighting, ventilation (fans), humidity and hydroponics systems to offer controlled environments for crop growth. However, these systems consume large amounts of energy. Thus, it is necessary to reduce this energy consumption in crop production. This review examines three modelling approaches for energy optimisation, namely: white box (physics-based), black box (data-driven), and grey box (a hybrid of the two). Each method's strengths and limitations are discussed in terms of their application to indoor farming. The findings emphasise the importance of selecting the right optimisation model based on specific goals and resources, with the potential to significantly improve energy efficiency in indoor farming. Further research is encouraged to refine these models and support sustainable food production.