Conceptual design and performance optimization of a nighttime electrochemical system for electric power generation via radiative cooling. (1st March 2022)

• Record Type: Journal Article
• Authors: Zhang, Xin; Ang, Yee Sin
• Is Part Of: Energy. Volume 242(2022)
• Publication Date: 2022-03-01
• Subjects: Nighttime -- Electrochemical cycles -- Radiative cooling -- Optimum design; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2021.123034
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: The conceptual design of a nighttime electrochemical system (NECS) based on radiative cooling for generating electrical power from dark night sky is proposed. Such a low temperature and passive device is capable of generating electricity during nighttime without active input of heat. A comprehensively theoretical model is developed to study its performance characteristics and parametric optimum design. The model predicts that an output power density larger than 2 W/m 2 at 303.15 K is achievable, which is potentially more advantageous than that of previously proposed nighttime thermoelectric generator. The calculated results show that the heat convection conditions, optimized geometry structure, and the choice of selective radiative cooler play a critical role in improving the device performance. This work reveals the new concept of the NECS and provides important insights for the optimal designs of the NECS, thus paving a new way towards high-performance nighttime electric power generation. Graphical abstract: Reliable energy access remains a challenge, particularly in off-grid regions throughout the world. While solar cells have enabled distributed power generation during the day, no comparable alternative exists at night. In this work, a nighttime electrochemical system (NECS) based on radiative cooling for generating electrical power from dark night sky is presented. Such low temperature and passive devices are capable of generating electricity at night without active input of heat. Furthermore, a theoretical model is developed to study its performance characteristics and parametric optimum design. The model predicts that a maximum power density of 2 W/m 2 operating at 303.15 K is achievable, which is potentially more advantageous than that of previously proposed nighttime thermoelectric generator. The results also show that the heat convection conditions, optimized structure, and the choice of selective radiative cooler play a critical role in improving the device performance. This work reveals the new concept of NECSs and provides important insights for the optimal designs of NECSs, thus paving a new route towards high-performance nighttime power generation. Image 1 Highlights: Nighttime electrochemical power generators via radiative cooling are proposed. Such low temperature and passive devices can generate electricity during nighttime. A comprehensive theoretical model of the system is developed. A power density larger than 2 W/m 2 at 303.15 K is achievable. The performance characteristics and optimum designs are determined.