An Environmental Optimization Model for Bioenergy Plant Sizes and Locations for The Case of Wood-Derived SNG in Switzerland

Abstract

Bioenergy from woodfuel has a considerable potential to substitute fossil fuels and alleviate global xD;warming. One issue so far not systematically addressed is the question of the optimal size of bioenergy plants xD;with regards to environmental and economic performance. The aim of this work is to fill this gap by modeling xD;the entire production chain of wood and its conversion to bioenergy in a synthetic natural gas plant both with xD;respect to economic and environmental performance. Several spatially explicit submodels for the availability, xD;harvest, transportation and conversion of wood were built and joined in a multi-objective optimization model to xD;determine optimal plant sizes for any desired weighting of environmental impacts and profits. xD;We find a trade-off between environmental and economic optimal plant sizes. While the economic optima range xD;between 75 – 200 MW, the environmental optima are with 10 – 40 MW significantly smaller. Moreover, the xD;economic optima are highly location specific and tend to be smaller if the biomass resource in the geographic xD;region of the plant is scarcer. The results are robust with regards to the effect on global warming as well as with xD;respect to the aggregated environmental impact assessment methods Ecoindicator ’99 and Ecological Scarcity xD;2006.