To address the needs of rapidly changing energy markets, an energy data management system capable of supporting higher utilization of renewable energy sources is being developed. The system receives flexible offers from producers and consumers of energy, aggregates them on a regional level and schedules the aggregated flexible offers to balance forecast energy supply and demand. This paper focuses on formulating and solving the optimization problem of scheduling aggregated flexible offers within such a system. Three metaheuristic scheduling algorithms (a randomized greedy search, an evolutionary algorithm and a hybrid between the two) tailored to this problem are introduced and their performance is assessed on a benchmark test problem and two realistic problems. The best results are achieved by the evolutionary algorithms, which can efficiently handle thousands of aggregated flex-offers.
I. IntroductionRapidly changing electrical energy markets, which are faced with deregulation, increased smart metering and requirements for higher utilization of renewable energy sources, seek new solutions to support their flexibility, ensure reliable supply, and balance the costs and benefits of the involved parties. A system to serve the needs of a deregulated electricity market and enable the integration of a higher rate of energy from distributed and renewable sources is being developed in the European Seventh Framework Programme project MIRABEL (Micro-Request-Based Aggregation, Forecasting and Scheduling of Energy Demand, Supply and Distribution) [1]. The project proposes a conceptual and infrastructural approach to supply and demand side management where electricity producers and consumers issue flexible offers (termed flexoffers), indicating flexibilities in start time and energy amount. These flex-offers are then processed by the MIRABEL system to balance electricity supply and demand.As electricity market regulations vary across the countries, the Harmonized Electricity Market Role Model [2] was chosen as a common platform to build upon in MIRABEL. This model defines the roles of producers and consumers, sometimes denoted by a common term prosumers. A collection of metering points for imbalance settlement is called the balance group and the role providing balance responsibility and financial security for a balance group is the balance responsible party (BRP).Balance group is the basic domain where the MIRABEL system will be applied. To assist the BRP in equalizing