The overuse of fossil fuels has caused a serious energy crisis and environmental pollution. Due to these challenges, the search for alternative energy sources that can replace fossil fuels is necessary. Hydrogen is a widely acknowledged future energy carrier because of its nonpolluting properties and high energy density. To realize a hydrogen economy in the future, it is essential to construct a comprehensive hydrogen supply chain that can make hydrogen a key energy carrier. This paper reviews the various technologies involved in the hydrogen supply chain, encompassing hydrogen production, storage, transportation, and utilization technologies. Then, the challenges of constructing a hydrogen supply chain are discussed from techno-economic, social, and policy perspectives, and prospects for the future development of a hydrogen supply chain are presented in light of these challenges.

Smart grids are the ultimate goal of power system development. With access to a high proportion of renewable energy, energy storage systems, with their energy transfer capacity, have become a key part of the smart grid construction process. This paper first summarizes the challenges brought by the high proportion of new energy generation to smart grids and reviews the classification of existing energy storage technologies in the smart grid environment and the practical application functions of energy storage in smart grids. Secondly, optimization planning and the benefit evaluation methods of energy storage technologies in the three different main application scenarios, including the grid side, user side, and new energy side, are analyzed. The advantages and shortcomings of the current research are also pointed out. Furthermore, the paper sheds light on the pressing issues that demand further consideration in energy storage planning. Finally, the aspects that warrant attention in the future application and promotion processes are elucidated in detail, culminating in a comprehensive understanding of the energy storage technologies in smart grids.