This paper deals with the energy management of a hybrid power system, which consists of a photovoltaic (PV) system, diesel generators, battery, and ultracapacitor for a mobile hospital. The proposed power system can supply energy to shelter hospitals for better treatment of patients in remote states, particularly in the event of a pandemic situation such as Coronavirus Disease 2019 (COVID-19). For this reason, a hybrid power system in which a diesel generator is used with a photovoltaic energy source for reliable availability of power supply. Moreover, battery and ultracapacitor are also integrated to obtain a hybrid power generation and storage system to ensure the smooth operation of mobile hospitals irrespective of weather conditions. A boost converter is used with PV panels to operate them in either maximum power tracking mode or power curtailment mode. The battery is connected to a bidirectional reversible DC-DC converter for direct-current (DC) bus voltage regulation and state of charge control. The ultracapacitor is associated with the battery to compensate for the peak power. The diesel generator is connected in parallel with the photovoltaic generator, battery, and ultracapacitor to continuously provide the power required by the load. The integrated operation of all generation sources and storage systems is complex for shelter hospitals. Therefore, an efficient energy management algorithm is developed to manage the continuous energy flow between different elements of the hybrid power system and mobile hospital load through the control of the power converters. Finally, validation results are presented to show the effectiveness of the proposed energy management algorithm for the hybrid power system.