As can be seen in Fig. 9, with the relative humidity increasing, the total power generation decreases firstly and then increases. The power generation achieves maximum of 1.51 GWh when the ambient air is saturated and reaches minimum while the relative humidity comes to a critical value around 60%. The total power generation for the moist ambient air is higher than that GNE0877 for the dry ambient when the relative humidity exceeds about 80% from the figure. Besides the power generation, the smoothing of the power output also counts much for the performance of the SUPP. Fig. 9 shows orgasm the peak-to-valley power ratio decreases from about 10.67 to 3.54 with the increasing of the relative humidity. The negative gradient of the ratio is low when the relative humidity of the ambient air is under the level of about 60%. But the downtrend becomes significant with a further increase in the relative humidity due to the condensation of the vapor. Thus, from the perspective of the smoothing of the power output, the relative humidity is beneficial for the operation of the SUPP.