The Project Preparation Technical Assistance was implemented between July 2000 and January 2001 in three stages: (i) conduct of case studies of representative biomass gas models, (ii) implementation of feasibility studies where the models in initial case studies were judged not to be suitable for replication and (iii) preparation of the investment project. Each step included technical, social, environmental, financial and economic assessments within the four provinces of Henan, Hubei, Jiangxi and Shanxi.