With the expansion of electricity spot market, there have been more factors affecting clearing prices considering renewable energy, carbon emissions trading, and others. Assessing the impact of key factors on price is beneficial to the controllability and stability of electricity prices in spot markets. Therefore, this paper proposes a method to analyze the key factors influencing price based on sensitivity analysis. Firstly, an index system is constructed to evaluate the influence on clearing price, including factors from unit cost, unit operation and system operation. To study the specific impact of various factors, a spot market clearing model considering carbon emissions trading is introduced in this paper. Finally, the sensitivity analysis method is used to compare the influence of each factor on clearing price in markets with different ratios of renewable energy. In the case study, a 39-node system is used to verify the effectiveness of the method and loads in valley-load period is proved to be the most critical factor in the market with high ratio renewable energy.
Keywords electricity spot market, clearing simulation, nodal price, influencing factor, sensitivity analysis