Empa_Bioenergie_ExecSumm_engl.pdf

Bundesamt für Energie BFE

Bundesamt für Umwelt BAFU

Bundesamt für Landwirtschaft BLW

LIFE CYCLE ASSESSMENT OF ENERGY

PRODUCTS:

ENVIRONMENTAL ASSESSMENT OF BIOFUELS

- Executive Summary -

Rainer Zah

Heinz Böni

Marcel Gauch

Roland Hischier

Martin Lehmann

Patrick Wäger

Empa

Technology and Society Lab

Lerchenfeldstrasse 5

CH-9014 St. Gallen, Switzerland

www.empa.ch/tsl

rainer.zah@empa.ch

Publication data

Rainer Zah, Heinz Böni, Marcel Gauch, Roland Hischier, Martin Lehmann & Patrick Wäger (Empa):

Life Cycle Assessment of Energy Products: Environmental Assessment of Biofuels

Bern, 22nd May 2007

Produced under a contract from the Federal Office for Energy (BFE), the Federal Office for the

Environment (BFE) and the Federal Office for Agriculture (BLW):

Bruno Guggisberg (BFE)

Daniel Binggeli (BFE)

Lukas Gutzwiler (BFE)

Norbert Egli (BAFU)

Daniel Zürcher (BAFU)

Amira Ellenberger (BAFU)

Anton Candinas (BLW)

Reto Burkard (BLW)

Project Management:

Niels Jungbluth, ESU-services Ltd., Uster

Critical Reviewer:

Fredy Dinkel, Carbotech, Basel

English translation:

Thomas Ruddy

Full report (in german) available at: www.empa.ch/biofuels

The authors are exclusively responsible for the conclusions of this report.

Abstract

The objective of this study is to evaluate the environmental impact of the entire production chain of

fuels made from biomass used in Switzerland. Firstly the study supplies an analysis of the possible

environmental impacts of biofuels suitable as a basis for political decisions. Secondly an “environ-

mental life-cycle analysis“ (LCA) of the various biofuels is done, which can be used as a basis for

granting an exemption from the excise duty on hydrocarbon oil. In addition, the impacts of fuel use are

compared with other uses for bioenergy such as the generation of electricity and heat. The study

based on the Swiss database of environmental inventories ecoinvent gives a holistic comparison of

the environmental impacts of biofuels; however neither the costs of biofuels nor the social conse-

quences of their production are evaluated. The results refer to average values from the year 2004 in

the respective production countries and are to be taken as a snapshot of factors relevant to the fuels’

use in Switzerland. Thus the study cannot provide any answers to questions concerning future impacts

– for instance, on food prices.

In principle, each of the fuels examined (bioethanol, biomethanol, biodiesel and biogas) can be pro-

duced in an environmentally friendly way – it depends on what raw materials and production technolo-

gies are used. Most of the environmental impacts can be attributed to the agricultural cultivation of the

respective raw materials (feedstocks). The environmental impact from fuel processing is usually much

lower. The environmental impact from the transport from the production site to Swiss filling stations is

even less, even when the biofuels are produced overseas. The present study shows that with most

biofuels there is a trade-off between minimizing greenhouse gases (GHG emissions) and a positive

environmental LCA. It is true that GHG emissions can be reduced by more than 30% with a number of

biofuels. However most of these supply paths show greater impacts than petrol for various other envi-

ronmental indicators.

The environmental LCA was done using two different methods: one was the Swiss method of ecologi-

cal scarcity (Environmental Impact Points, UBP 06), which evaluates the difference between environ-

mental impacts and legal limits. The other one is the European Eco-indicator 99 method, which quanti-

fies the damage done to human health and ecosystems. Both methods show the same results: in the

case of tropical agriculture it is primarily the slashing and burning of rainforests that releases the larg-

est quantities of CO2, causes an in-crease in air pollution and has massive impacts on biodiversity. In

the moderate latitudes it is partly the lower crop yields, partly the intensive fertilizer use and mechani-

cal tilling of the soil that are the causes of a bad environmental evaluation. However unlike the case of

fossil fuels, the environmental impacts of biofuels can be greatly reduced by specific measures. The

study shows in sensitivity analysis how, for instance, a reduction in methane leakage can improve the

LCA of biogas production or what effect a prohibition of slash and burn would have on the LCA of bio-

diesel made from palm oil.

Overall, the results of the study show that any promoting of biofuels by a tax break, for instance, must

be done so as to target the best production paths. Not all biofuels per se can reduce environmental

impacts as compared to fossil fuels. Currently, of all the production paths investigated, it is especially

the use of biogenic wastes ranging from grass to wood that brings a reduction in environmental impact

as compared with petrol. Since the potential of domestic bioenergy today is limited – and will be so in

future – bioenergy will not solve our energy problems. However it if the available biomass is trans-

formed into energy in an efficient and environmentally friendly manner, while at the same time con-

sumption is reduced and energy efficiency in-creased, these alternative energy carriers can together

with other forms of renewable energy play a role in our future energy supply that should not be ne-

glected.

Environmental assessment of biofuels, R. Zah et al., Empa

Executive Summary

In connection with the worsening scarcity of fossil fuels and climate change the idea of using renew-

able energy is attracting interest both in the Swiss public eye and in industry. Fuels made from bio-

mass – so-called biofuels – are currently the most important form of renewable energy in road trans-

portation and could at least over the short to medium term take on a role in reducing greenhouse

gases and our dependency on fossil fuels.

In Switzerland therefore important political decisions have to be made against a background of giving

a tax break for renewable fuels as opposed to diesel and petrol.

Although biofuels from renewable resources exist, a wider range of environmental impacts may result

from their cultivation and processing than those from fossil fuels. These range from excessive fertilizer

use and acidification of soil to a loss of biodiversity caused by slash and burning rainforest. Besides

that, one should not forget that expanding agricultural energy production may lead to land use conflicts

with other land uses such as food production or the conservation of natural areas. Therefore energetic

efficiency and the attainable reduction in greenhouse gases should not be taken as the sole criteria for

a holistic environmental evaluation of these alternative fuels.

The objective of this study is to evaluate the environmental impacts in the whole process chain of bio-

fuels used in Switzerland. Firstly an action-oriented analysis of the environmental impacts of renew-

able energy carriers was to be developed. Secondly the objective was to draw up a “comprehensive

environmental analysis” of the various biofuels, which could serve as a basis for enforcing the exemp-

tion of renewable fuels from the excise duty on hydrocarbon oil. In addition, the effects of using the

fuel were to be compared with other ways to use bioenergy, such as heat and power generation.

Methodology

In order to determine the effects of biofuels on the environment as exactly as possible, the methodol-

ogy of life cycle assessment (LCA) was chosen. That entails evaluating the energy and resource con-

sumption and all pollutant emissions over the entire life cycle needed to satisfy a defined function (e.g.

filling up a car tank with 1 MJ of energy at a Swiss filling station). The necessary inventory data for

biofuels were collected in an initial subproject and complemented by additional data from the Swiss

environmental inventory database (ecoinvent 1.3). The impacts on the environment were then first

determined with the aid of action-oriented indicators , which described the direct environmental im-

pacts and suggested to us ways to deal with them. Secondly an environmental overall assessment

was done, during which the individual damaging effects were weighted and aggregated, so that all

environmental impacts could be assessed (see Figure 1). It was important to remember that the ag-

gregated evaluation methods (in this study Environmental Impact Points 1 , UBP 06, and eco-indicator

99 2 ) included their own relative weighting factors for the various environmental impacts (e.g. the

greenhouse effect versus excessive fertilizer use). For political discussion it is therefore important not

to rely solely on the overall evaluation, but rather on a case-by-case basis to include the individual

action-oriented indicators it is based on.

The study covered renewable energy forms both from Switzerland and foreign production; however

Switzerland was always taken the place of utilization. The assessment was done on a cradle-to-grave

basis; i.e. all relevant environmental impacts from biomass cultivation, from the occurrence of a bio-

genic waste substance to its energetic utilization. The year 2004 was chosen as the main observation

period, although in some cases we had to rely on older or newer data.

1 The method of ecological scarcity (UBP 06). The mass unit consists of environmental impact points. This Swiss method

estimates the total environmental impact from the difference between emission values and the legal limits.

2 A fully aggregated environmental evaluation method based on the proliferation and damaging effects of emissions.

Environmental assessment of biofuels, R. Zah et al., Empa

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