Participating in market trading is an essential step to promote the sustainable development of renewable energy. To properly deal with the uncertainty of renewable energy, it is important to establish a reasonable bidding deviation assessment mechanism in the electricity market. Based on the analysis of existing research and practice, the bidding deviation assessment mechanism are summarized into two categories, that is, the outcome assessment mechanism (OAM) and the performance assessment mechanism (PAM). Models of the mechanism are built to analyze the principles of the two types of mechanism, and the impact of aggregation effect of renewable energy on the assessment is discussed. Simulation results show that the outcome assessment mechanism will lead to over-assessment, but is conducive to motivating renewable energy stations (RESs) to actively reduce bidding deviation; while the performance assessment mechanism can ensure the cost-recovering of balancing dispatch, but make RESs unable to improve market behavior except to passively accept penalties at settlement. To promote the development of renewable energy, both assessment mechanisms have room for further improvement.

renewable energy; spot market; bidding deviation; assessment mechanism