Storage of biomass fuel - a greenhouse gas emission risk?

Bioenergy is considered to be a very important potential energy source when limiting greenhouse gas(GHG) emissions in the near future. Growing utilization of biofuels will, however, increase the need for using storage activities and this might have an effect on GHG saving potentials. The magnitude of material and energy losses due to storage of various biofuels has been recognized but there can be found very little evaluations and no measurements of the amounts of GHG emissions. The purpose of the work presented here was to evaluate GHG emission risks due to biofuel storage. The evaluations indicated that potential GHG emissions from storage can, in some cases, be much greater than the emissions known from the rest of the biofuel production and transportation chain. When substituting a fossil fuel with a biofuel, as much as 97-98% of GHG emissions can be avoided in the most favourable situations. If long-term storage of chipped biofuel is included in the production chains, the percentage might decrease and become less than 60-80%. This presentation focus on (i) the phenomena expected to cause GHG emissions (ii) present the evaluation method used and (iii) compare the emission risks due to storage with the magnitude of GHG emissions known from other parts of the biofuel production and transportation chain. Finally some suggestions of further research are presented.