A price-based approach for influencing distributed resources in the participation to the grid ancillary market

The current distribution and transmission grid is facing new challenges in terms of resiliency, especially thinking to the new trends in the energy scenario. The increasing penetration of renewable and distributed sources, together with the growing diffusion of the electric-based room conditioning and the perspectives on electric vehicles, will stress the power network to new levels. To overcome such criticality, new flexibility mechanisms are proposed: the adoption of local smart devices that can actively communicate with the "upper grid levels" (e.g. with the DSO or with the VPP aggregator) and optimally operate the local generation and consumption equipment can represent a low-cost option to differ new investments on the power grid by providing ancillary services, like the tertiary balance of the grid. The small-size prosumers shall be equipped with intelligent EMSs, whose communication with the "upper" grid manager can be based on different parameters. In the present work the remuneration of the exceeding electricity and the penalty for not respecting a pre-defined amount of energy exchanged with the electricity network are proposed as a driver for influencing the performance and the scheduling of an EMS installed in a local site. The considered case study is represented by a small enterprise (being representative of the Italian scenario), facing a plurality of loads and both renewable and fossil generators, whose pieces of equipment are optimally scheduled by a purposefully developed heuristic algorithm, capable to optimize the plant operations also considering the requests for ancillary services from the distribution grid. The application of the algorithm embedded in the EMS is considered, in terms of results, from an economic perspective, with the target to understand the sensitivity of the response of distributed micro-grids to new technical and economic scenarios. The analyzed results consider two example days in winter and summer for the hypothesized facility and supposing two different feasible options for the new electric market of flexibility.