To ensure dynamic balance between the electricity demand and supply， an online purchase electricity now（OPEN） system is proposed based on the integration of the advance demand information and the virtual energy provisioning concept. The OPEN system allows for customers to input future electricity demands through an on-line database. The utility company， after consolidating the demand information， will be able to decide on an optimal generation and distribution scheme to satisfy customers' needs. Some preliminary research findings will be elaborated and discussed， including the OPEN system architecture， consumer input assessment， and database design. A preliminary design of the system is given.