A new cooling method by directly immersing the solar cells into phase-change liquid was put forward to cool dense -array solar cells in high concentrating photovoltaic system. A self -running system was built to study the feasibility of temperature control and the effect of bubbles generated by ethanol phase change under concentration ratio ranged between 219.8x and 398.4x. The results show that the cooling system is self-regulating without consuming extra energy and ethanol flow rate reaches up to 180.6 kg/(s.m(2)) under 398.4x. The temperature of solar cells distributes in the range between 87.3 degrees C and 88.5 degrees C, the surface heat transfer coefficient of electric heating plate is up to 23.49 kW/(m(2)K) under 398.4x. The bubble effect on electrical performance of triple junction solar cells is reported and the results show that I-sc and P-max decline 10.2% and 7.3%, respectively. A model based on bubble images illustrates that light loss at the interface between ethanol and bubble is the main reason to cut down the electrical performance. (C) 2016 Elsevier Ltd. All rights reserved.