Thermal assessment of flat reflector‐integrated collector storage using dynamic system testing and Q‐H procedures according to <scp>ISO</scp> 9459‐5 and <scp>ISO</scp> 9459‐2

Abstract This study evaluates the thermal performance of a newly designed Integrated Collector Storage (ICS) system with a Flat Reflector (FR) using both Dynamic System Testing (DST) and Q‐H procedures according to ISO 9459‐5 and ISO 9459‐2 standards, assessing its viability in various climates, including Tunisian, Saudi Arabian, Swedish, Greek, and German conditions. The experimental DST results revealed that the system with double glazing and flat reflectors has a total stored heat capacity (C s ) of 0.62 MJ/K, a useful collector surface area (Ac*) of 1.03 m 2 , and a storage tank heat loss coefficient ( U s ) of 10.79 W/K. The use of double glazing allows reducing the loss coefficient to 4.15 W/K, at the expense of decreasing the daily efficiency from 38.9% to 22.9%. The annual solar fraction varies significantly with the season, reaching its lowest at 49% in January and February and peaking at 98% in July and August, while in Riyadh (Saudi Arabia), the solar fraction reaches 100% from May to October, and in Stockholm (Sweden), the system provides a productivity of 615 kWh per year, demonstrating its viability in both hot and cold climates, and highlighting both the economic and environmental benefits of using such ICS systems by comparing the revenue received with the amount of reduced CO 2 emissions when replacing conventional energy sources. The outcomes further highlight the value of striking a balance between environmental and economic factors when using the conceived system in different locations.