Limiting global warming to 1.5°C would be a herculean task to all human beings. To reach this goal, the world would have to curb its carbon emissions by at least 49% of 2017 levels by 2030 and then achieve carbon neutrality by 2050. Installing renewable energy systems is a key to achieving the decarbonization goal. However, the intermittent nature of renewable energies is challenging because it can disrupt the daily operation of the electric grid. Energy storage technology is the key to resolve the problems of intermittency, volatility and low energy density in the large-scale utilization of clean and renewable energy. In addition, energy storage technology has promising applications in industrial waste heat recovery, building energy saving, thermal management, power grid peak shaving, etc. Therefore, energy storage technology plays a critical role on the roadmap to achieve the goal of carbon neutrality. This special issue will focus on the recent advances in energy storage technologies in the convergence of carbon neutral transition, such as energy storage materials and devices, thermal management and control of energy storage systems, energy storage testing and evaluation, advanced manufacturing technologies for energy storage systems, and economic analysis and GHG emission analysis of energy storage technology.

  Through rigorous peer review, seven original research papers have been accepted. Among them, three papers focus on latent thermal storage system, one on an integrated thermal storage system and compressed air storage system, one on material properties of nanofluid as possible energy storage medium, and two on parametric study about the working conditions of electrolysis cells using numerical approach. These seven papers reflect the latest progress and stimulate further interest in new carbon neutral and energy storage technologies.

  We would like to express our gratitude to all the contributors, reviewers and the journal office team for their great support in ensuring the high quality of this special column.

Under the carbon peaking and carbon neutrality strategy, the demand for diversified, clean and low-carbon energy utilization is increasingly urgent. The low-carbon development and energy security are facing major challenges. It is therefore necessary to build new ways of low-carbon use for high-carbon energy and promote the innovation of low-carbon heat conversion technology. 

Clean and efficient utilization of coal plays a decisive role in the energy revolution and has faced big challenges. Circulating fluidized bed (CFB) combustion technology, as an advanced energy utilization technology, has been developed rapidly in the last 30 years. It has the advantages of wide fuel adaptability, good environmental performance and wide range of load regulation. CFB technology will play an important role in the clean and efficient utilization of coal for carbon neutrality. 

This special issue covers six subjects and focuses on the experiments, simulations and applications of Circulating fluidized bed technologies and relevant fields. Through rigorous peer review, nineteen original research papers have been accepted, which are broadly categorized into Power generation technology, Boiler deep peak regulation technology, Solid waste firing and co-firing technology, Industrial low-carbon technology, Ultra-low pollutant emission technology, Oxy-fuel combustion technology and Energy storage technology. 

We would like to express our gratitude to all the contributors, reviewers and the journal office team for their great support in ensuring the high quality of this special issue.