Participation of a PV power plant to the Italian Ancillary Service Market via a hydrogen-based power-to-power system: economic impact of Secondary Frequency Reserve provision

This work investigates the economic profitability of Secondary Frequency Reserve (SFR) ancillary service provision to the Italian electric grid through energy storage systems. The operation of a hydrogen-based Power-to-Power system, designed to supply a constant uninterruptible 1 MWel load with locally generated electricity by a solar PV field, is studied when acting on both the Day-Ahead Market (DAM) and the Ancillary Service Market (ASM). Considering historical time series of PV generation, electricity prices on the DAM, and price-quantity combinations of accepted offers on the ASM, a mixed-integer linear optimization problem is set up that minimizes the annual average cost of electricity to the load. Provision of SFR services with an optimal bidding strategy allows the average cost of electricity to decrease by about 15% with respect to the operation on the DAM only.