Flexible photovoltaic power systems: integration opportunities, challenges and advances

Photovoltaic power systems, consisting of solar modules, energy storage, and power management electronics, are of great importance for applications ranging from off-grid and portable power to ambient light harvesting for sensor nodes. Co-design and integration of the components using printing and coating methods on flexible substrates enable the production of effective and customizable systems for these diverse applications. In this article, we review photovoltaic module and energy storage technologies suitable for integration into flexible power systems. We discuss the design of electrical characteristics for these systems that enable them to power desired loads efficiently, as well as strategies for physically combining the components. Functions and design considerations of power management electronics are presented along with recent progress toward printed and flexible power electronics. We analyze both hybrid and fully flexible photovoltaic systems and the critical role of the application in the choices of materials and architectures for the system components.