China will realize its Carbon Peak in 2030 and Carbon Neutrality in 2060. Aside from the substantial improvement of energy efficiency in traditional energy transmission, the massive utilization of solar energy will be a great driving force for China to realize the “double Carbon” in the near future. However, the supply of solar energy is intermittent and strongly unstable in nature while demand for energy is periodical and fluctuating.

When integrated with energy storage systems, solar systems can overcome the shortcomings in supply and demand. This will require global scholars to work together. In this area, a key aspect is the performance improvement of solar thermal systems. The performance of solar thermal systems can be further improved by system optimization, heat transfer enhancement, and operation optimization. The efficient operation of solar thermal systems combined with thermal energy storage systems is the most important aspect for large-scale utilization of solar. It should be noted that the utilization of solar thermal energy will have a substantial impact on building environment.

This Special Issue aims to invite the latest experimental, numerical, theoretical, and technical developments in solar thermal systems combined with thermal energy storage. We welcome original research and review articles.

Potential topics include but are not limited to the following:

• Utilization of nanofluids in solar thermal systems
• Operation and optimization of solar thermal systems
• Material designs for thermal energy storage
• Efficient operation of thermal energy storage
• Utilization of solar thermal energy in buildings