This paper reviews the costs and technologies involved in an integrated system for the production of electricity from biomass in general and wood in particular It first examines the economics of gasification, showing that the potential for this form of renewable energy lies in either processing low-cost wastes or relying on some sort of fiscal incentive, even at relatively large scales of operation and with high-efficiency processes. The paper then considers all the elements required with respect to wood handling and preparation, gasification, gas quality and gas cleaning, and establishes the criteria for their selection for delivery of a clean gas to a gas turbine or engine, Special emphasis has been placed on the technology status and key uncertainties that are considered to be crucial to the success or failure of a biomass-based IGCC system. The main conclusions are that wood handling, storage, drying, comminution and screening are well established and present no uncertainties in operation and performance. The technology of biomass gasifiers is sufficiently advanced to justify a substantial demonstration plant to prove the total IGCC concept and obtain reliable performance data. There are still areas of uncertainty, but these are relatively minor and will not be resolved until and unless a large integrated plant is built. Gas cleaning has been successfully developed in laboratories to the point where large-scale demonstration and long-term operating experience are necessary. This area can be considered the least developed and most likely to create problems in a demonstration plant. Turbine and turbine fuel specifications are imperfectly defined, although engines are known to be more tolerant of contaminated fuel gas.
