The numerical simulation of a large-scale hybrid SCPP (an additional waste heat source is connected to the collector-to-chimney transition section) is performed based on a transient model. The daily dynamic profiles of power output, mass flow rate of condensed water and temperature at a representative point for continuous 24 h are obtained, as well as the daily total electricity output and the power difference-to-average ratio (PDAR) defined as the ratio of the peak-valley difference of the daily power profile to the daily average. The effect of effective waste heat flux (EWHF) on the power output by changing the solar radiation intensity is evaluated. Results show that the incorporation of waste heat with enough high heat flux into SCPP causes clear enhancement of the power output. With the increase in the EWHF from 0 to 2 GW, the daily total electricity output increases by 119.99% and the PDAR drops from 1.61 to 0.8. Moreover, the PDAR is smaller for weaker solar radiation. This indicates that enough high waste heat flux helps to flatten the daily profile of the plant power output, especially for weak solar radiation. While low waste heat flux has little influence on the power output and the PDAR.