OpenTUMFlex: A flexibility quantification and pricing mechanism for prosumer participation in local flexibility markets

Abstract

Increasing distributed energy resource penetration requires additional methods to tackle grid congestion and enhance reliability. In addition, advancements in demand-side management can help strengthen distribution network stability. A viable approach is to develop local flexibility markets (LFMs) to aggregate prosumer flexibility potentials and offer grid ancillary services. To facilitate such prosumer–market interactions, an open-source model, named OpenTUMFlex is developed in this study to quantify and price prosumer flexibility. The core of this model is an energy management system that optimizes prosumer data to obtain a cost-optimal operation schedule. Flexibility potential is defined as all possible deviations from this optimal operation without violating device constraints. Flexibility services are characterized as positive and negative flexibility based on the energy exchanged with the grid. Also, a predictive pricing mechanism is introduced to identify the minimum price the prosumer needs to be compensated for their flexibility service. The outcome of this model is a flexibility offer table using which the prosumer can bid in the LFMs. An iterative interaction between the OpenTUMFlex model and LFM is possible as the model integrates the flexibility service requirements from the selected bid into its operational schedule and generates a new optimal operation schedule with renewed flexibility offers. The model is analyzed using two case studies where a sample flexibility service implementation for different prosumer devices is discussed. In addition, a unique flexibility representation technique is introduced to illustrate the flexibility offers graphically. Future research will focus on identifying the impact of forecast uncertainty on flexibility quantification.