The stand-alone photovoltaic-battery (PV/B) hybrid energy system has been widely used in off-grid equipment and spacecraft due to its effective utilization of renewable energy. For they are interconnected and distinct from each other, the ground and space stand-alone PV/B hybrid energy systems are compared in this review. On the one hand, advanced and well-established technologies are demanded in both fields. On the other hand, special needs are also d. The stand-alone photovoltaic-battery (PV/B) hybrid energy system has been widely used in off-grid equipment and spacecraft due to its effective utilization of renewable energy. For they are interconnected and distinct from each other, the ground and space stand-alone PV/B hybrid energy systems are compared in this review. On the one hand, advanced and well-established technologies are demanded in both fields. On the other hand, special needs are also demonstrated due to the different working environments and tasks. A considerable amount of academic research has accumulated on the ground and space stand-alone PV/B hybrid energy systems. Nevertheless, the existing research directions are quite disorganized and unbalanced for both space and ground stand-alone PV/B hybrid energy systems. For this reason, there is a strong drive to collect recent research and conduct a clear, balanced literature review. In the first place, dilemmas of the stand-alone PV/B hybrid energy system in different scenarios were analyzed. Then, the current system-level solutions were summarized. Moreover, the development history and new research results on the component level of solar cells and secondary batteries were introduced. The progress of lithium battery performance in a low-temperature environment was highlighted. Finally, the study pointed out possible development directions of the stand-alone PV/B hybrid energy system in space and on the ground.••Focusing on the stand-alone PV/B hybrid energy system in space and on the ground.••The challenges faced by the system in both conditions are mentioned and compared.••Technical development in system-leve and component-level are provided.••Recent results about overcoming extreme temperatures are highlighted.Photovoltaic-battery hybrid energy systemStand-alone energy systemPV cellLi-ion batteryIn the past two decades, the depletion of traditional energy sources, environmental degradation, and unreliable energy supply have led to an energy crisis which draws wide attention. There is an increasingly urgent demand for inexhaustible, clean, and credible energy sources like wind, solar, and biomass. Solar energy, as one of the most common green energy sources, has been analyzed by a plethora of researchers. At present, the most direct and effective way to harness solar energy is using photovoltaic (PV) cells to convert solar energy into electricity. Fig. 1 shows the solar PV global capacity and annual additions from 2009 to 2020,,. According to the International Energy Agency's key projections, the average annual increase in global renewable energy generation between 2021 and 2026 will be more than 150GW. The total installed PV capacity will increase to 1.826TW in 2026.As a promising clean energy system, the PV power system can be divided into the grid-connected system and the off-grid system according to the connection relationship with the power grid. In this review, off-grid PV power systems are the focus. As the PV cells are greatly affected by darkness and season in an off-grid system, batteries or capacitors are attached to the system to secure the power supply. In academia, the off-gird PV system combined with secondary batteries is called the stand-alone PV/B system, which is also known as the mi. In this section, the obstructions in the current ground and space stand-alone PV/B hybrid energy systems are reviewed. Similarities and differences between the stand-alone PV/B hybrid energy system in two environments are investigated. Meanwhile, new research progress at the system level has been provided based on requirement analysis. The new tech.
