A life cycle energy use, CO 2 emissions and cost input evaluation of a 650 MW Biomass Chemical Looping Gasification Combined Cycle (BCLGCC) and a Biomass/Coal Integrated Gasification Combined Cycle (BIGCC/CIGCC) power generation plants with and without (w/o) CO 2 capture & storage (CCS) are analysed. These were then compared to coal/biomass combustion technologies. The life cycle evaluation covers the whole power generation process including biomass/coal supply chain, electricity generation at the power plant and the CCS process. Gasification power plants showed lower energy input and CO 2 emissions, yet higher costs compared to combustion power plants. Coal power plants illustrated lower energy and cost input; however higher CO 2 emissions compared to biomass power plants. Coal CCS plants can reduce CO 2 emissions to near zero, while BCLGCC and BIGCC plants with CCS resulted in negative 680 kg-CO 2 /MWh and 769 kg-CO 2 /MWh, respectively, which is due to the higher biomass utilization efficiency for BCLGCC compared to BIGCC hence less CO 2 captured and stored. Regarding the total life cycle costs input (TLCCI), BCLGCC with and without CCS equal to 149.3 £/MWh and 199.6 £/MWh, and the total life cycle energy input (TLCEI) for both with and without CCS is equal to 2162 MJ/MWh and 1765 MJ/MWh, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]