Recent advances in using nanofluids in renewable energy systems and the environmental implications of their uptake

• DOI: 10.1016/j.nanoen.2021.106069
• Publication Date: 2021-04-16T12:48:38Z
• Authors: Omid Mahian; Evangelos Bellos; Christos N. Markides; Robert A. Taylor; Avinash Alagumalai; Liu Yang; Caiyan Qin; Bong Jae Lee; Goodarz Ahmadi; Mohammad Reza Safaei; Somchai Wongwises
• Keywords: 1007 Nanotechnology; 0202 electrical engineering, electronic engineering, information engineering; 0303 Macromolecular and Materials Chemistry; 02 engineering and technology; 0912 Materials Engineering; 7. Clean energy

Abstract It has been more than two decades since the discovery of ‘nanofluids’ – mixtures of common liquids and solid nanoparticles with at least one dimension below 100 nm in size. While colloidal suspensions of particles (which include larger particles) have been studied for several decades, the term ‘nanofluids’ designates fluid systems that have enhanced thermal and optical properties. Although barriers to their commercial adoption remain, the field of nanofluids has continued to grow. Many studies have considered the effects of adding nanoparticles on the thermal efficiency and exergy efficiency of renewable energy systems particularly solar systems, however, few have investigated their potential for emission reductions. Critically, since renewable energy technologies aim to reduce the environmental impact of energy systems, this review focuses on whether nanofluids provide a net environmental benefit. Thus, in addition to providing a comprehensive overview of this body of literature from an environmental perspective, this review also highlights areas for future work that could help ensure that nanofluids have a net positive environmental impact in renewable energy systems going forward.