Nanofluids have become increasingly popular for solar thermal applications due to their tuneable optical and thermal properties. These properties have been studied in detail in the literature, but to ensure commercial viability, dispersion stability of the nanoparticles is critical. Thus, this work investigates the stability of spectrally selective nanoparticles (core-shell silver-silica nanodiscs) in a glycerol base fluid for use as a liquid optical filter. This nanofluid was subjected to thermal testing and intensive UV-irradiation to determine the stability, and thus viability, of the nanofluid as a spectrum splitting nanofluid for photovoltaic/thermal (PV/T) applications. (C) 2017 Elsevier Ltd. All rights reserved.