AGGREGATING RESIDENTIAL ELECTRICAL WATER HEATERS INTO A VIRTUAL POWER PLANT TO PROVIDE SERVICES TO THE GRID.

This work proposed a methodology for developing a Virtual Power Plant (VPP) used to
aggregate electric water heaters (EWHs) and heat pump water heaters. The main objective is to quantify the flexibility services these can offer to the grid in terms of volume and cost. For a fleet of 1000 electric water heaters, with an average capacity of 195 L, a maximum power of 2500 kW was obtained for the Virtual Power Plant, for an equivalent storage capacity of 15 MWh. The greatest potential for flexible demand is found between 7 and 10 a.m., representing 34 % of the total capacity of the VPP. The results show how EWHs can provide positive and negative regulation to the grid for different activation times. It is observed that the VPP has higher potential in terms of positive regulation than negative, but that this potential is tightly linked to the chosen control strategy. The Virtual Power Plant flexibility evaluation is finally validated using a digital twin of the water heaters portfolio with a simplified control strategy. Results demonstrate the suitability of the proposed model, but further work is required to accurately quantify the ancillary services to be provided to the grid.