For achieving carbon neutrality, Mitsubishi Heavy Industries, Ltd. (MHI) has accumulated experience in biomass co-firing and 100% biomass firing for pulverized coal-fired steam power plants of various types and output ranges in Japan as well as overseas. As the latest example, large (1,000-MW-class) ultra-supercritical steam power plants in which pulverized coal is fired have started biomass co-firing operation at the ratio of 10% or more (calorie basis).