Carnot batteries represent state-of-the-art technology in the fields of thermal energy storage and dispatchable electricity generation. The thermal energy usually comes from solar thermal power plants. The present study analyzes and optimizes a hybrid biomass-solar thermal central tower power plant coupled with a carbon dioxide cycle in a supercritical state and thermal energy storage, known as a Carnot battery system. Thermal and economic optimization were carried out for the power cycle, thermal storage, biomass, and the power plant's main parameters to obtain the current available minimum levelized cost of energy, LCOE.