UCSD Sustainability Solutions Institute

An economic and technical analysis of the use of separated wood biomass as a feedstock for gasification for a 3 MW power plant was conducted for the Miramar Landfill, located in San Diego County, CA. The method to generate combustible gas from the biomass is based on a dual-fluidized bed gasification process which operates at atmospheric pressure with air and produces a high quality producer gas with little nitrogen. The objective of the study was to determine the economic feasibility of the proposed biomass power system in terms of the potential revenue streams and costs. Major economic considerations in the analysis include feedstock, capital, and operating costs. Regulatory issues, inclusive of production credits, renewable energy incentives, and feed-in tariffs are addressed as significant economic inputs. The Miramar landfill, in San Diego County, CA is representative of a typical existing urban landfill, with corresponding feedstock and some market for separated wood biomass. The economic analysis of the proposed 3MW gasification power plant indicates that it would not have a net positive NPV under the current urban scenario. More likely successful candidates are landfill sites in more rural areas or urban sites, where new landfills are being developed or where the landfill is no longer operational but has become a transfer station. In all cases waste heat sales are a critical element in determining economic viability.