Die Bodenkultur - Journal for Land Management, Food and Environment

W. Kriegl and W. Schneeberger:

A comparative economic evaluation of two uses of biogas: in electricity production and for distribution into the national gas grid


Model calculations are used to compare the economic efficiency of two alternative uses of biogas produced from maize silage: electricity production or upgrading to enable distribution into the national gas grid. A sensitivity analysis examines how changes in the underlying assumptions regarding investment costs, annual full load hours, maize silage price, methane yield, service life, sale of heat and plant size impact the costs per kWh electricity and upgraded biogas. The costs of upgraded biogas and electricity produced from biogas are then compared with the market prices for natural gas and electricity. The costs for both biogas uses are higher than the market prices for electricity and natural gas, thus the excess costs per Nm3 methane are applied as a measure to get an insight into the relative worth of each use. According to the calculations converting biogas into electricity for sale to the grid causes lower excess costs per Nm3 methane than upgrading biogas for pipeline insertion. Key words:  Biogas, electricity production, upgrading, national gas grid, costs.