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BIOENERGY FOR EUROPE: WHICH ONES FIT BEST?

BIOENERGY FOR EUROPE: WHICH ONES FIT BEST?

62 4 Environmental

62 4 Environmental results: presentation, discussion and interpretation • In Austria, rape seed might be cultivated instead of cattle fodder in the fields. In this case, more cattle feed would need to be imported, e.g. soy bean from Brazil. The cultivation of soybean takes place at the expense of tropical rainforest. Therefore, values for the ecosystem occupation from the tropical rainforest might have to be used, and soy bean as reference values for rape seed. Conclusions Concerning the impact of energy crops on soil quality and biodiversity as assessed in this study the following conclusions can be drawn: • The assessment of the impact of soil quality by energy crops could only partly be carried out due to a lack of data. Most gaps were found in data concerning the weight and the rate of decomposition of the fractions of plant material. • No data are available to validate the results obtained so far with this method. Hence the value of the method used could not be ascertained. • The method does not take into account the scarcity of ecosystems and their ability to regenerate. Therefore, results obtained with this method should be interpreted with care. • There appears to be a difference in the impact on soil quality between cereals, perennials, and other crops. More research is needed to verify and explain this result. Results on harmful rainfall An indication of the erosion hazard during a calendar year is obtained using data, per cropping stage, for the cropping factor and rainfall, which are combined into the so called harmful rainfall (see Chapter 3.4.1). The results obtained showed significant differences, thus for example regarding the energy crops, the amount of harmful rainfall varies from 138 (willow in Germany) to 695 mm/a (sunflower in Italy). In contrast, the amount for grass fallow varies from 56 (Austria) to 143 mm/a (Netherlands) – for more data and results see Annex 7.5. Nevertheless, some results could be drawn: • Rape seed appears to result in high values for harmful rainfall. • As shown in Germany and the Netherlands, perennial crops cause lower erosion risks than annual crops. This may well be explained by the provision of winter cover. • For the annuals, wheat and triticale appear to result in lower erosion risks than sugar beet and rape seed . This is possibly due to the larger row intervals for the latter. • Top three in erosion hazard are sunflower, hemp and sugar beet. Conclusions Concerning the impact of energy crops on erosion as assessed by the method of harmful rainfall, the following conclusions can be drawn: • The method uses readily available data and can easily be carried out. However, factors not included in this method may play a large role in the occurrence of erosion. Therefore, the method needs validation with actual data on erosion. • The method may be improved by including factors to assess the effect of management practices on erosion risk. • Following this method, soil cover is the best way of reducing the harmful effect of rainfall. This is demonstrated by the lower erosion risks from perennial crops and cereals with short row intervals. Still, more research is needed to investigate this issue further and to integrate it into the issue of land use discussed within LCAs. This accounts for both the assessment of primary data as well as an adoption and/or modification of the methodology to LCA standards.

4.3 European results: biofuels for specific objectives 63 4.3 European results: biofuels for specific objectives In the following sections, comparisons between the various biofuels are presented. These are based on the individual comparisons of the biofuels with their respective fossil counterparts. The objective here is to assess which one of the investigated biofuels is best suited for any given purpose. Table 4-3 shows the utilisation objectives and the related biofuels. Some results are described as “non-significant”. This refers to a possible reversal of signs if the uncertainties are very large. Therefore, these assessments are not based on the magnitude of the values shown in the graphs given in “inhabitant equivalents”, but rather on the magnitude of the relative differences biofuel-fossil fuel related to the fossil fuel (bio-fossil / fossil) without normalisation. (The results of the life cycle comparisons biofuel-fossil fuel presented as relative differences are documented in Chapter 7.2.). For further information on the result presentation, the parameters used and sensitivity analysis see Chapter 4.1 and for more detailed information Chapter 3. Table 4-3 Biofuels compared in the light of different objectives Objective Life cycle comparisons considered Technical applications I: Heat production Willow versus light oil Miscanthus versus light oil Traditional firewood versus light oil Wheat straw versus heating oil Technical applications II: Transport Rape seed oil methyl ester versus diesel fuel Sunflower oil methyl ester versus diesel fuel ETBE from sugar beet versus MTBE Ecological aspects I: Efficiency of land use Triticale versus hard coal Willow versus light oil Miscanthus versus light oil Rape seed oil methyl ester versus diesel fuel Sunflower oil methyl ester versus diesel fuel ETBE from sugar beet versus MTBE Ecological aspects II: Impacts related to saved energy Triticale versus hard coal Willow versus light oil Miscanthus versus light oil Rape seed oil methyl ester versus diesel fuel Sunflower oil methyl ester versus diesel fuel ETBE from sugar beet versus MTBE Traditional firewood versus light oil Wheat straw versus heating oil Biogas from swine excrements

Bioenergy Update 10-02 - General*Bioenergy