High Efficiency Operational Reserve by SOFC for the Effective Grid Integration of Variable Renewable Energies

For an effective grid integration of a large share of intermittent renewable energy sources such as a photovoltaic and a wind power, the flexible operation of the centralized or decentralized thermal power plants are required as a control reserve of demandsupply balance (frequency control). It is cleared that the Solid Oxide Fuel Cell and Gas Turbine (SOFC/GT) with additional air compressor system offers high efficiency in the wide range load operation. The efficiencyload ratio curve of the Gas Turbine Combined Cycle (GTCC) and SOFC/GT with air compressor system are applied to the secondary control reserve (SCR) operation units, and the daily schedule of power units in the modelled power grid is calculated. Since the efficiency at low load is high in SOFC/GT with air compressor system, the total fuel cost of the modelled power grid diminishes in the case that the SOFC/GT with air compressor system is operated at low load as a load frequency control (LFC) unit for the SCR.