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90 6 Conclusions and

90 6 Conclusions and recommendations Regarding the categories for which reliable values were obtained, the results are summarised below (see also Table 6-1). The full results are given in the Chapters 4.1 (for Europe) and 7.1 (for each country). The main conclusions are generally similar between the various countries and Europe: Use of fossil fuels: all biofuels have, to a greater or lesser extent, advantages over their fossil equivalents regarding this category. This is due to the fact that through the production and use of biofuels the utilisation of fossil fuels is reduced. Greenhouse effect: this factor is causally connected to the use of fossil fuels (which leads to the emission of greenhouse gasses) and therefore gives very similar results, i. e. always to the advantage of the biofuels. Acidification: most biofuels show disadvantages for this category as well, with the exception of triticale and traditional firewood. Eutrophication: again the biofuels compare unfavourably against their fossil equivalents. The only exceptions are RME and SME in certain countries, which receive credits for co-products that make up for the impacts caused by the biofuel production and utilisation. The large differences for the cultivated crops are due to the utilisation of fertiliser and its inevitable partial escape into water bodies. Summer smog: most biofuels have (relatively small) advantages over the fossil fuels, with the exception of the transport fuels where the results cannot be regarded as significant. Table 6-1 Results of the European comparisons between biofuels and fossil fuels Biofuel Use of fossil fuels Greenhouse effect Acidification Eutrophication Summer smog Triticale + + +/- - + Willow + + - - + Miscanthus + + - - + Rape seed oil methyl ester (RME) + + - - +/- Sunflower oil methyl ester (SME) + + - +/- +/- ETBE from sugar beet + + - - +/- Traditional firewood + + +/- - + Wheat straw + + - - + Biogas from swine excrements + + - - + + advantage for biofuel; - advantage for fossil fuel; +/- insignificant or ambiguous result The following categories/parameters yielded results which – for various reasons explained in each section – are less reliable than those discussed above: Nitrous oxide: all biofuels have higher emission values than the fossil fuels. The large differences for the cultivated crops are due to the utilisation of fertiliser in agricultural production. Since however the net effect of nitrous oxide regarding ozone depletion is not yet ascertained, the results should not form a part of a final assessment. Human toxicity: this category assesses human toxicity via air. Depending on the comparison the results showed either very small differences or else were in favour of the fossil fuels. Due to a lack of data however, the results have a high uncertainty and should therefore not form a part of a final assessment. Ecotoxicity and persistent toxicity: these categories assess acute and persistent toxicity towards humans and ecosystems. It was decided not to include these results in the graphs because of a lack of data and more specifically inconsistencies in data quality for the two compared systems: for biofuels, pesticides were assessed on a very detailed level, whereas the same level of detail was not obtained for the fossil fuels. Due to these differences, it was not possible to draw any conclusions, but the data on biofuels serve as a good basis for further work on the subject.

6 Conclusions and recommendations 91 Biodiversity and soil quality: this category was assessed using four parameters, namely • ecosystem occupation as an indicator of loss of biodiversity, • ecosystem occupation as a measure for life support functions of the soil, • harmful rainfall (as an indicator of erosion) and • soil compaction. For the first and the last one of these no results were obtainable due to a lack of suitable methodology and data. Regarding ecosystem occupation as a measure for life support functions of the soil there appears to be a difference in the impacts of cereals, perennials, and other crops respectively. However, more research is needed to verify and explain this result. Perennial crops and cereals with short row intervals show lower erosion risks due to their higher degree of soil cover, which reduces the effect of harmful rainfall. Result of the comparison between triticale and hard coal for electricity production Use of fossil fuels Greenhouse effect Acidification Eutrophication Summer smog Nitrous oxide** Human toxicity** * How to interpret the diagram Advantages for biofuel Advantages for fossil fuel -8000 -6000 -4000 -2000 0 2000 4000 6000 8000 European inhabitant equivalents* per 100 million kWh The figure shows the results of comparisons between complete life cycles where hard coal is substituted by triticale for electricity generation. The unit refers to an amount of one hundred million kWh of electricity. This is equivalent to the average electricity requirement of about 20,000 inhabitants of Europe in one year or a triticale production of about 5,500 ha/a. In this case for example the amount of fossil fuel saved is equal to the amount which nearly 6,000 European citizens would on average consume in one year (this is what is meant by “European inhabitant equivalents”). See Chapter 4.2.1 for a discussion of the results. Figure 6-1 Example of result diagram for the comparison between triticale and hard coal Result interpretation: concerning the interpretation of the results, different approaches are possible, since this part goes beyond the scientific analysis and incorporates subjective choices. For the presentation of the quantitative results two different approaches were chosen by the various country representatives, as explained in Chapter 3.5. The first involved a discussion of the direct values calculated in the life cycle impact assessment. The second one used converted units in order to enable a comparison of the relative impacts regarding the various categories. For this purpose the so-called inhabitant equivalents were used, which express the impacts of the respective fuel production and consumption in com-

Bioenergy Update 10-02 - General*Bioenergy
Maximising the environmental benefits of Europe's bioenergy potential
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