Mode: Mixed
Photovoltaic (PV) panels are typically less than 20% efficient in delivering electricity from the Sun’s energy. The efficiency losses are especially pronounced when PV panels are exposed to high irradiance conditions on warm, sunny days, which lead to higher temperature operation. Of the total amount of sunlight incident on PV panels, over 70% is lost to the environment as waste heat. This loss has motivated the development of ‘hybrid’ PV-thermal (PV-T) collectors, which combine PV cells with a contacting fluid. The fluid recovers waste heat from the cells, thus delivering a potentially useful thermal output, while simultaneously cooling the cells and increasing their electrical efficiency. Recently, a new concept that we refer to as multifunctional ‘PV-X’ collector technology has emerged, in which secondary processes are integrated synergistically with the PV cells, exploiting the available waste heat to perform additional functions directly within the collector. In this talk, we will present conventional and advanced PV-T and PV-X collector concepts and designs, along with their underlying operational principles. We will explore opportunities for further developing these technologies and examine how new materials can drive improvements from the component to the system level, while discussing the potential of integrating these technologies into broader solar-energy systems capable of providing cooling, heating, power, fuels or clean water.
Professor Christos Markides is Professor of Clean Energy Technologies and Head of the Clean Energy Processes Laboratory at Imperial College London. He is also Editor-in-Chief of Applied Thermal Engineering, and founding Editor-in-Chief of recently established journal AI Thermal Fluids. He specialises in applied thermodynamics, thermal-fluid flows and heat/mass transfer processes in high performance devices, technologies and systems for thermal-energy recovery, tilisation, conversion or storage, with a particular focus on solar- and waste heat applications. He has authored >460 articles on related topics; recent highlights include: “A review of solar hybrid photovoltaic-thermal (PV-T) collectors and systems”, “High-efficiency bio-inspired hybrid multigeneration photovoltaic leaf”. His publications have attracted ~22,000 citations (h-index = 79) to-date. He has won multiple awards, including most recently IChemE’s Global ‘Clean Energy Medal’ in 2025, and received Imperial College’s President Awards for Research Excellence in 2017 and Teaching Excellence in 2016. He is also founding Director and CEO of Imperial spin-out Solar Flow.
Clean water and clean air are vital for public health. This project focuses on developing high-efficiency and environmentally sustainable filters for removing harmful air/water pollutants. The team has developed novel architectures and functionalities for the filters to achieve high permeance, high removal efficiency, and excellent reusability.
