An overview of supercapacitors for integrated PV-energy storage panels

One limitation of photovoltaic energy is the intermittent and fluctuating power output, which does not necessarily follow the consumption profile. Energy storage can mitigate this issue as the generated power can be stored and used at the needed time. Integrating energy storage directly in the PV panel provides advantages in terms of simplified system design, reduced overall cost and increased system flexibility. Incorporating supercapacitors directly in the PV panel on module or cell level raises some challenges regarding the electrical integration, such as charge controlling for the capacitors, capacitor matching, as well as internal power electronics layout. Physical integration of graphene supercapacitors with solar cells, at module-or cell-level presents challenges related to physical dimensioning, thermal management and life expectation of the entire system. The main goal of this article is to review the supercapacitor technologies and perform a comparison between the available supercapacitors in the market and selecting the most suitable type for developing supercapacitor-based integrated PV-energy storage systems, to achieve optimal electrical and physical integration.