The capability of shifting the electricity generation or consumption to proper time of the day, also defined as energy shift (ES), is the key factor to ensure the power balance， especially under high penetration of variable renewable energy (VRE). However, the ES is not characterized and traded as an independent product in current market mechanisms. In this letter, the marginal utility of an ES is assessed and leveraged to characterize the effective ES, while a novel market scheme is proposed considering the trading of both ES and energy level (EL). The proposed scheme can well integrate ES producers such as virtual power plants that cannot be rewarded sufficiently to actively participate in the current market because they are principally labeled as EL consumers. Finally, the novel concept and mechanism are illustrated by a numerical study and verified to outperform the existing price schemes on integrating the ES resources and VRE.