5 years ago



106 7 Annex Ecological

106 7 Annex Ecological aspects II: impacts related to saved energy – Austria Greenhouse effect Acidification Eutrophication Summer smog Nitrous oxide Human toxicity How to interpret the diagram Advantages for biofuel Advantages for fossil fuel -3000 -2000 -1000 0 1000 2000 3000 Austrian inhabitant equivalents per 100 TJ saved fossil fuel Triticale RME Firewood Straw Biogas The figure shows the results of complete life cycle comparisons where all biofuels investigated by Austria are used for energy production instead of their respective fossil counterparts. The results for the various categories are given with reference to the category "Use of fossil fuel", i.e. 100 TJ of fossil energy saved. For example, for every 100 TJ of fossil energy saved through the substitution of light oil by traditional firewood, the amount of greenhouse gas emissions avoided is equal to those on average generated by about 1,100 Austrian inhabitants in one year. (This is what is meant by "Austrian inhabitant equivalents".) Conclusions European or national energy strategies cannot be based on a sole energy source or energy carrier. A prospective estimation of the bioenergy development is rather difficult. For an overall comparison the different levels of development, different types of useful energy, the different states of the technology and the different costs must be considered. The following table compares the chains only on the basis of fossil fuel saving and availability of land (based on a mix of bioenergy we have estimated a possible increase of 50 to 80 PJ until 2010 under a committed policy for Austria, the evaluation refers to a reduction of 20 PJ fossil energy per chain). Political and social effects are not taken in account. Impact category Triticale Firewood Wheat straw RME Biogas Greenh. effect Mio. t CO2 - 1.81 - 1.49 -1.45 - 1.05 - 3.64 Acidification 1000 t SO2 - 1.03 - 0.481 0.553 3.04 10.6 Eutrophication 1000 t NO3 12.2 1.216 0.910 - 7.74 6.36 Summer smog t Ethylene eq. - 48 19 129 - 122 - 2020 Nitrous oxide t N2O 215 - 22 151 1610 13 Feasibility Realistic Ambitious Possible Ambitious Impossible A negative sign means “advantage for bioenergy” Impacts for 20 PJ fossil fuel saved 6012

7.1 Country specific life cycle comparisons 107 All types of biofuels are well-suited to reduce the greenhouse gas emission in a substantial quantity. The highest effect per unit can be reached with biogas. The effects of triticale, wood and straw are similar, the difference is caused by the different fossil fuel counterparts. Biodiesel leads to the lowest effect. With all types of biofuels acidification, eutrophication, sommer smog and human toxicity will not be improved or deteriorated dramatically. Except RME the same results can be observed with nitrous oxide. With 20 PJ rape the overall Austria nitrous oxide burden would increase significantly (from 9,000 t/a to 10,600 t/a). With triticale, wood, straw and rape seed, savings of 20 PJ can be reached by each. Biogas from pig manure cannot be produced in the afforded quantity.

Bioenergy Update 10-02 - General*Bioenergy