Solar energy has gained considerable attraction in recent years due to its several benefits such as availability, low emission of greenhouse gases, and different applications. This renewable energy source can be utilized for heating, cooling, power generation, and desalination. Different technologies have been applied to exploit solar energy for the mentioned purposes. For power generation, photovoltaic panels, and solar thermal power plants are among the most used technologies. For heating and cooling applications, heat pumps and collectors can be used and for desalination. Various configurations have been introduced to directly or indirectly desalinate water. Similar to other technologies, the efficiency of solar energy systems has a key role in their selection and performance evaluation.

Despite several advantages of solar systems, their efficiency is relatively low compared with the currently used fossil fuel-based technologies. By improving the efficiency of these systems, they would be more cost-effective and compact. Moreover, it would be a motivation for consumers and policymakers to employ these systems. In this regard, different approaches have been used and suggested for improving their performance. Integrating solar systems with other technologies, applying them in polygeneration configuration, utilizing modified materials, and employing heat recovery units are among the most attractive approaches to reach performance enhancement of solar systems. Depending on the considered application and technology, performance enhancement approaches can vary.

The Special issue aims to bring together original research and review articles related to the performance enhancement of solar energy systems. In this regard, submissions focusing on performance improvement of various solar energy technologies, including photovoltaic/thermal (PV/T), thermal systems, etc, will be considered for publication.

Potential topics include but are not limited to the following:

• Efficiency enhancement of different solar systems by using novel and practical approaches
• Solar-based hybrid energy systems with enhanced overall efficiency
• Solar-based polygeneration systems with improved efficiency
• Concentrated solar power (CSP) technologies with improved efficiency