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BIOENERGY FOR EUROPE: WHICH ONES FIT BEST?

BIOENERGY FOR EUROPE: WHICH ONES FIT BEST?

58 4 Environmental

58 4 Environmental results: presentation, discussion and interpretation 4.2.7 Traditional firewood versus light oil / natural gas for residential heat production Use of fossil fuels Greenhouse effect Acidification Eutrophication Summer smog Nitrous oxide** Human toxicity** * How to interpret the diagram Advantages for biofuel Light oil Natural gas Advantages for fossil fuel -900 -800 -700 -600 -500 -400 -300 -200 -100 0 100 European inhabitant equivalents* per 100 TJ The figure shows the results of comparisons between complete life cycles where light oil and natural gas respectively are substituted by traditional firewood for heat production. The unit refers to an amount of 100 TJ of heat. This is equivalent to the average heat requirement of about 4,000 inhabitants of Europe in one year or a firewood production of about 900 ha/a. In this case for example the amount of fossil fuel saved if firewood replaces either of the fossil fuels is equal to the amount which nearly 800 European citizens would on average consume in one year (this is what is meant by “European inhabitant equivalents”). Remarks and conclusions The results show that both traditional firewood as well as light oil and natural gas have certain ecological advantages and disadvantages. • Advantages of the biofuel: use of fossil fuels, greenhouse effect, compared to natural gas also summer smog • Advantages of the fossil fuel: eutrophication, compared to natural gas also acidification • Low or no significance: comparison with light oil only: acidification and summer smog The data for ozone depletion and human toxicity tend to have a high uncertainty. Therefore these categories should not be included in the final assessment. (**See Chapter 4.1.2 and for details on all impact categories 3.3 and 3.4) A further assessment in favour of or against traditional firewood or light oil / natural gas cannot be carried out on a scientific basis, because for this purpose subjective value judgements regarding the individual environmental categories are required which differ from person to person.

4.2 European results: biofuels compared to fossil fuels 59 4.2.8 Wheat straw versus light oil / natural gas for district heat 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 Light oil Natural gas -1000 -500 0 500 1000 1500 European inhabitant equivalents* per 100 TJ The figure shows the results of comparisons between complete life cycles where light oil and natural gas respectively are substituted by wheat straw for heat production. The unit refers to an amount of 100 TJ of heat. This is equivalent to the average heat requirement of about 4,000 inhabitants of Europe in one year or a wheat straw production of about 1,300 ha/a. In this case for example the amount of fossil fuel saved if light oil is substituted by wheat straw is equal to the amount which more than 700 European citizens would on average consume in one year (this is what is meant by “European inhabitant equivalents”). Remarks and conclusions The results show that both wheat straw as well as light oil and natural gas have certain ecological advantages and disadvantages. • Advantages of the biofuel: use of fossil fuels, greenhouse effect, compared to natural gas also summer smog (very small) • Advantages of the fossil fuel: acidification, eutrophication, compared to light oil also summer smog • Low or no significance: – The data for ozone depletion and human toxicity tend to have a high uncertainty. Therefore these categories should not be included in the final assessment. (**See Chapter 4.1.2 and for details on all impact categories 3.3 and 3.4) A further assessment in favour of or against wheat straw or light oil / natural gas cannot be carried out on a scientific basis, because for this purpose subjective value judgements regarding the individual environmental categories are required which differ from person to person.

Bioenergy Update 10-02 - General*Bioenergy