Energy enhancement of building-integrated photovoltaic/thermal systems: A systematic review Hussein A. Kazem a , Miqdam T. Chaichan b , Ali H.A. Al-Waeli c , K. Sopian d , Naser W. Alnaser e , Waheeb E. Alnaser f,* a Faculty of Engineering, Sohar University, PO Box 44, Sohar, PCI 311, Oman b Energy and Renewable Energies Technology Research Centre, University of Technology, Iraq c Engineering Department, American University of Iraq, Sulaimani, Kurdistan Region, Iraq d Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak Darul Ridzuan, Malaysia e Department of Architecture and Interior Design, College of Engineering, University of Bahrain, Kingdom of Bahrain f Department of Natural Resources and Environment, College of Graduate Studies, Arabian Gulf University, Kingdom of Bahrain A R T I C L E INFO Keywords: Photovoltaic/Thermal system PV/T Electricity Thermal energy Energy in building ABSTRACT In urban areas with limited space, harnessing renewable energy, especially solar energy, can be a challenge. However, we can overcome this obstacle by using building facades to generate energy. Buildings significantly contribute to global energy consumption and greenhouse gas emissions. They require energy for various pro- cesses, both electrical and thermal. To address this, we can use photovoltaic/thermal (PV/T) systems, which can simultaneously produce electrical and thermal energies. By circulating a working fluid within the system, the surface temperatures of PV panels can be reduced, improving electrical efficiency. Integrating PV/T systems into building facades, known as building-integrated PV/T (BIPV/T) systems, enables efficient energy production and enhances the overall energy consumption of buildings. 1. Introduction The energy consumption of buildings is a critical aspect of modern society. Whether residential, commercial, or industrial, buildings ac- count for a significant portion of global energy demand [1]. They are central to various activities and processes that require energy, such as lighting, heating, cooling, ventilation, and powering electrical devices. Therefore, the efficient use of energy in buildings is crucial for sus- tainability, cost savings, and environmental preservation [2]. The importance of energy in buildings becomes even more apparent when considering the broader context of global environmental impact and energy consumption. Studies show that buildings contribute to a substantial portion of the world’s energy consumption, representing approximately 40 % of the overall demand [3]. This high energy con- sumption directly affects greenhouse gas (GHG) emissions, as 33 % of global GHG emissions are due to building energy consumption. As the world aims to address global warming and reduce its carbon footprint, improving energy efficiency and adopting renewable energy sources in buildings are critical priorities [4]. Recognizing the urgent need for energy-efficient buildings, researchers, engineers, architects, and policymakers have focused on developing innovative solutions and strategies. The objective is to minimize energy waste, optimize energy performance, and integrate renewable energy technologies into the built environment [5]. These efforts encompass a wide range of approaches, including building design, insulation, efficient HVAC (heating, ventilation, and air condi- tioning) systems, and smart building automation [6]. Solar energy has emerged as a promising source for powering buildings among the various renewable energy technologies [7]. Solar energy offers several advantages, including its abundance, sustainabil- ity, and compatibility with the built environment. Photovoltaic systems, capable of converting sunlight directly into electricity, and solar thermal (ST) systems, which utilize sunlight for heating purposes, have gained significant attention as viable options for energy generation in buildings [8]. This study sets the stage for exploring the pivotal role of buildings building energy and the urgency of developing energy-efficient solu- tions. By highlighting the energy in buildings and their environmental impact, it underscores the importance of effective energy management strategies and utilizes BIPV/T systems. In addition, it focuses on utilizing * Corresponding author. E-mail address: walnaser@agu.edu.bh (W.E. Alnaser). Contents lists available at ScienceDirect Solar Compass journal homepage: www.elsevier.com/locate/solcom https://doi.org/10.1016/j.solcom.2024.100093 Received 29 June 2024; Received in revised form 23 September 2024; Accepted 24 September 2024 Solar Compass 12 (2024) 100093 Available online 26 September 2024 2772-9400/© 2024 The Authors. Published by Elsevier Ltd on behalf of International Solar Alliance. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).