Ensuring Energy Trading in Electricity Market Highly Penetrated with Renewable Energy

This paper presents the technical measures used in the Yunnan electricity market to facilitate the trading mechanisms in ensuring energy trading and minimizing deviations from market contracts. A stochastic generation optimization model is proposed to tackle the generation variability of variable renewable energy in the market. A time-rolling model for checking consuming capability is presented to prevent energy imbalances induced by arbitrage from fictitious transactions by consumers from impeding system operation. Moreover, a set of congestion management methods accounting for transmission constraints in the interconnected grid and hydraulic coupling among cascade hydroplants are proposed to ensure safe grid operation and avoid unnecessary water spillages in cascade hydroplants. Furthermore, a series of measures related to contract deviations handling are presented to hedge market participants from much exposure to contract deviations and minimize deviation costs caused by failures to deliver the contracted energy in markets based on medium- and long-term transactions. Through three years of applications and improvements, the proposed measures are verified to be feasible and effective in improving market efficiency for ensuring energy trading, reducing deviation costs, promoting renewable energy integration, and facilitating low-carbon electricity development.