A new configuration of phase change material (PCM) heat sink has been developed to be combined with a
building integrated concentrated photovoltaic (BICPV) system. This new proposed system includes PCM
encapsulated in aluminum pack and immersed in nanofluid container to improve thermal conductivity. A
comprehensive numerical model was validated and simulated to evaluate thermal and electrical performance of
the proposed system for both passive and active cooling conditions. Two different configurations of nanofluid-
PCM enclosures with single PCM pack or multi-smaller packs were compared with conventional BICPV-PCM
system. Melting and solidification of PCM were also studied with solar concentration ratio of 5. In passive
cooling, single-pack configuration regulated the silicon temperature of CPV below 78 ◦C with more uniform
temperature distribution. Whereas the multi-packs configuration demonstrated 97% phase transition to liquid
PCM which provided the highest stored thermal energy. The performance improvement would be attributed to
the enhancement of thermal conductivity and natural convection of nanofluid in PCM container. Furthermore, in
active cooling condition, the silicon temperature controlled under 43 ◦C with uniform distribution. The nanofluid
flow could be solidified up to 97% and 90% of initially melted PCM after 60 min for multi-packs and single-pack
configurations, respectively.