Power system is facing a grand challenge in recent years. On one hand, renewable energy sources (RES) are taking much more share than decades ago, on the other, user side electricity load keeps growing rapidly. In order to ensure electricity reliability and cost efficiency, source-grid-load-storage (SGLS) project is thus being proposed. In this paper, the optimal operation of SGLS project is being studied. In order to ensure social optimum and reduce RES curtailment, a two-stage operation optimization method is being proposed. Then, based on a real-world SGLS case, the model is solved and analyzed. Last, the impact of SGLS project on load balance and reducing RES curtailment is being studied. On top of that, how SGLS would impact the electricity price clearing is also being studied and analyzed. The result has shown that SGLS project is capable of mitigating RES locally with high efficiency. Moreover, SGLS could take advantage of current mechanism since SGLS could purchase electricity from the grid when electricity price is low and generate power itself while electricity price is high, as shown in its final cleared electricity price.