Life cycle assessment of future fossil technologies with and without carbon capture and storage

The NEEDS project of the European Commission (2004-2008) continues the ExternE series, aiming at improving and integrating external cost assessment, LCA, and energy-economy modeling, using multi-criteria decision analysis for technology roadmap up to year 2050. The LCA covers power systems suitable for Europe. The paper presents environmental inventories and cumulative results for selected representative evolutionary hard coal and lignite power technologies, namely the Ultra-Supercritical Pulverized Combustion (USC-PC) and Integrated Gasification Combined Cycle (IGCC) technologies. The power units are modeled with and without Carbon Capture and Storage (CCS): The three main technology paths for CO2 capture are represented, namely pre-combustion, post-combustion, and oxy-fuel combustion. Pipeline transport and storage in geological formations like saline aquifers and depleted gas reservoirs, which are the most likely solutions to be implemented in Europe, are modeled for assumed average conditions. The entire energy chains from fuel extraction through, when applicable, the ultimate sequestration Of CO2, are assessed, using ecoinvent as background LCA database. The results show that adding CCS to fossil power plants, although resulting in a large net decrease of the CO2 effluents to the atmosphere per unit of electricity, is likely to produce substantially more GHG than claimed by near-zero emission power plant promoters when the entire energy chain is accounted for, especially for post-combustion capture technologies and hard coal as a fuel. Besides, the lower net power plant efficiencies lead to higher consumption rate of non-renewable fossil fuel. Furthermore, consideration of the full spectrum of environmental burdens besides greenhouse gas (GHG) results in a less definite picture of the energy chain with CCS than obtained by just focusing on GHG reduction.