Abstract
Purpose
Environmental life cycle assessment (LCA) is today an important methodology to quantify the life cycle based environmental impacts of products, services or organisations. Since the very first LCA studies, the cumulative energy demand CED (also called ‘primary energy consumption’) has been one of the key indicators being addressed. Despite its popularity, there is no harmonised approach yet and the standards and guidelines define the cumulative energy demand differently. In this paper, an overview of existing and applied life cycle based energy indicators and a unifying approach to establish characterisation factors for the cumulative energy demand indicator are provided. The CED approaches are illustrated in a building’s LCA case study.
Methods
The five approaches are classified into two main concepts, namely the energy harvested and the energy harvestable concepts. The two concepts differ by the conversion efficiency of the energy collecting facility. A unifying ‘energy harvested’ approach is proposed based on four theses, which ensure consistent accounting among renewable and non renewable energy resources.
Results and discussion
The indicator proposed is compared to four other CED indicators, differing in the characterisation factors of fossil and biomass resources (upper or lower heating value), the characterisation factor of uranium and the characterisation factors of renewable energy resources (amount harvested or amount harvestable). The comparison of the five approaches is based on the cumulative energy demand of a newly constructed building of the city of Zürich covering the whole life cycle, including manufacturing and construction, replacement and use phase, and end of life.
The cumulative energy demand of the life cycle of the building differs between 336 MJ oil-eq/m2a (‘CED uranium low’) and 836 MJ oil-eq/m2a (‘CED energy statistics’). The main differences occur in the use phase. The main reason for the large differences in the results are the different concepts to determine the characterisation factors for renewable and nuclear energy resources.
Conclusions
The energy harvested approach ‘CED standard’ is a consistent approach, which quantifies the energy content of all different (renewable and non-renewable) energy resources. The ‘CED standard’ approach and the impact category indicator results computed with this approach reflect the safeguard subject ‘energy resources’ but not (no other) environmental impacts. The energy harvested approach proposed in this paper can readily be implemented in different contexts and applied to various data sets.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Notes
The maximum systematic deviation in fossil CED values between approaches using the higher and the lower heating value, respectively, is about 10 %.
www.probas.umweltbundesamt.de/php/index.php?, accessed on July 10, 2014.
www.minergie.ch, accessed on August 12, 2014.
References
Balouktsi M, Lützkendorf T, Frischknecht R (2014) An analysis of the calculation of the indicators related to embodied energy and embodied GHG emissions in the different LCI databases—survey. IEA EBC Annex 57, Subtask 1 (ST1)
Boesch ME, Hellweg S, Huijbregts MAJ, Frischknecht R (2007) Applying cumulative exergy demand (CExD) indicators to the ecoinvent database. Int J Life Cycle Assess 12(3):181–190
Boustead I, Hancock GF (1979) Handbook of industrial energy analysis. Ellis Horwood Ltd., Chichester
CML (2013) CML-IA Characterisation Factors. In: Centre for Environmental Sciences (CML) (ed). Leiden, The Netherlands, retrieved from: http://www.leidenuniv.nl/cml/ssp/databases/cmlia/cmlia.zip
Dones R, Bauer C, Röder A (2007) Kohle. In: Dones R (ed) Sachbilanzen von Energiesystemen: Grundlagen für den ökologischen Vergleich von Energiesystemen und den Einbezug von Energiesystemen in Ökobilanzen für die Schweiz, Vol. ecoinvent report No. 6-VI, v2.0. Paul Scherrer Institut Villigen, Swiss Centre for Life Cycle Inventories, Dübendorf, CH retrieved from: www.ecoinvent.org
EN 15643-2 (2011) EN 15643-2:2011—Sustainability of construction works—Assessment of buildings. European Committee for Standardisation (CEN), Brussels
EN 15804 (2013) EN 15804:2012 + A1:2013—Sustainability of construction works—Environmental product declarations—Core rules for the product category of construction products. European Committee for Standardisation (CEN), Brussels
EN 15978 (2012) EN 15978:2012—Sustainability of construction works—Assessment of environmental performance of buildings—Calculation method. European Committee for Standardisation (CEN), Brussels
EnergieSchweiz für Gemeinden, Stadt Zürich and Schweizerischer Ingenieur- und Architektenverein SIA (2014) Bilanzierungskonzept 2000-Watt-Gesellschaft, 3. Überarbeitete Fassung. EnergieSchweiz für Gemeinden, Stadt Zürich, Schweizerischer Ingenieur- und Architektenverein SIA, Ettenhausen
Friedrich EG, Baurat G, Müller G (1922) Die Bauwirtschaft im Kleinwohnungsbau. Kritische Betrachtung der neuzeitlichen Bauweisen und Mitteilung von Erfahrungen mit Baustoffen. Verlag von Wilhelm Ernst & Sohn, Berlin
Frischknecht R (1997) The seductive effect of identical physical units. Int J Life Cycle Assess 2(3):125–126
Frischknecht R, Heijungs R, Hofstetter P (1998) Einstein’s lesson on energy accounting in LCA. Int J Life Cycle Assess 3(5):266–272
Frischknecht R, Althaus H-J, Dones R, Hischier R, Jungbluth N, Nemecek T, Primas A, Wernet G (2007a) Renewable energy assessment within the cumulative energy demand concept: challenges and solutions. In: Proceedings from: SETAC Europe 14th LCA case study symposium: Energy in LCA—LCA of Energy, 3–4 December 2007, Gothenburg, Sweden
Frischknecht R, Jungbluth N, Althaus H-J, Bauer C, Doka G, Dones R, Hellweg S, Hischier R, Humbert S, Margni M, Nemecek T (2007b) Implementation of life cycle impact assessment methods. ecoinvent report No. 3, v2.0. Swiss Centre for Life Cycle Inventories, Dübendorf, CH, retrieved from: www.ecoinvent.org
Fritsche UR, Jenseit W, Hochfeld C (1999) Methodikfragen bei der Berechnung des Kumulierten Energieaufwands (KEA)
Geddes P (1884) An analysis of the principles of economics. In: Proceedings of the Royal Society of Edinburgh, XII, pp 943–980
Goedkoop M, Hofstetter P, Müller-Wenk R, Spriensma R (1998) The Eco-indicator 98 explained. Int J Life Cycle Assess 3(6):352–360
Hunt RG, Franklin WE, Welch RO, Cross JA, Woodal AE (1974) Resource and environmental profile analysis of nine beverage container alternatives. Midwest Research Institute for U.S. Environmental Protection Agency, Washington DC
International Organization for Standardization (ISO) (2006a) Environmental management—Life cycle assessment—Principles and framework. ISO 14040:2006; Second Edition 2006-06, Geneva
International Organization for Standardization (ISO) (2006b) Environmental management—Life cycle assessment—Requirements and guidelines. ISO 14044:2006; First edition 2006-07-01, Geneva
International Organization for Standardization (ISO) (2012) Environmental management—Life cycle assessment—Illustrative examples on how to apply ISO 14044 to impact assessment situations; 2nd edition. Technical Report ISO/TR 14047; First edition. International Organization for Standardization, ISO, Geneva
ISO (2007) Sustainability in building construction—Environmental declaration of building products. ISO 21930:2007. International Organization for Standardization (ISO)
ISO (2010) Sustainability in building construction—Framework for methods of assessment of the environmental performance of construction works. ISO 21931:2010. International Organization for Standardization (ISO)
ISO (2011) Sustainability in building construction—Sustainability indicators. ISO 21929:2011. International Organization for Standardization (ISO)
Jolliet O, Margni M, Charles R, Humbert S, Payet J, Rebitzer G, Rosenbaum R (2003) IMPACT 2002+: a new life cycle impact assessment methodology. Int J Life Cycle Assess 8(6):324–330
KBOB, eco-bau and IPB (2014) ecoinvent Datenbestand v2.2+; Grundlage für die KBOB-Empfehlung 2009/1:2014: Ökobilanzdaten im Baubereich, Stand April 2014. Koordinationskonferenz der Bau- und Liegenschaftsorgane der öffentlichen Bauherren c/o BBL Bundesamt für Bauten und Logistik, retrieved from: www.lc-inventories.ch
Klöpffer W (1997) In defense of the cumulative energy demand. Int J Life Cycle Assess 2(2):61
Ponsioen TC, Vieira MDM, Goedkoop MJ (2014) Surplus cost as a life cycle impact indicator for fossil resource scarcity. Int J Life Cycle Assess 19(4):872–881
PRé Consultants (2012) SimaPro 7.3.3, Amersfoort, NL
Bundesrat S (2012) Strategie Nachhaltige Entwicklung 2012–2015. Interdepartementaler Ausschuss Nachhaltige Entwicklung, Bern, retrieved from: http://www.are.admin.ch/themen/nachhaltig/00262/00528/index.html?lang=de
SIA (2009) Merkblatt 2031: Energieausweis für Gebäude gemäss SN EN 15217 und SN EN 15603. Schweizerischer Ingenieur- und Architektenverein (SIA), Zürich
SIA (2010) Merkblatt 2032: Graue Energie von Gebäuden, SIAth edn. Schweizerischer Ingenieur- und Architektenverein (SIA), Zürich
SIA (2011a) Merkblatt 2040: SIA-Effizienzpfad Energie. Schweizerischer Ingenieur- und Architektenverein (SIA), Zürich
SIA (2011b) Merkblatt 2039: Mobilität—Energiebedarf in Abhängigkeit vom Gebäudestandort. Schweizerischer Ingenieur- und Architektenverein (SIA), Zürich
UBA (1999) KEA: mehr als eine Zahl—Basisdaten und Methoden zum kumulierten Energieaufwand (KEA)
VDI (1997) Cumulative Energy Demand—Terms, Definitions, Methods of Calculation. In: VDI-Richtlinien 4600. Verein Deutscher Ingenieure, Düsseldorf
VDI (2012) Cumulative energy demand—terms, definitions, methods of calculation. In: VDI-Richtlinien 4600. Verein Deutscher Ingenieure, Düsseldorf
Wagner R, Weisskopf T (2014) Erdsondenpotenzial in der Stadt Zürich. Stadt Zürich, Amt für Hochbauten, Fachstelle Energie- und Gebäudetechnik
Züger Y, Gutri C (2012) Ökobilanz Erstellung—Bauprojekte im Vergleich, Vol. 17. Status-Seminar «Forschen für den Bau im Kontext von Energie und Umwelt», ETH Zürich (ed. Stadt Zürich A. f. H., Fachstelle nachhaltiges Bauen), Zurich, retrieved from: http://www.stadt-zuerich.ch/content/hbd/de/index/hochbau/nachhaltiges_bauen/Fachinformationen/Themenschwerpunkt_6_-_Graue_Energie_und_Stoffkreislaeufe.html#abgeschlossene_studien2012
Acknowledgments
We wish to thank Greg Foliente, CSIRO, Melbourne, Australia and two anonymous reviewers for the valuable comments on earlier versions of this manuscript. This work has been carried out in the context of the IEA EBC Annex 57 “Evaluation of Embodied Energy and Greenhouse Gas Emissions for Building Construction”. We like to thank the Swiss Office of Energy and the Project Management Jülich, Germany (PTJ) and the German Federal Ministry for Economic Affairs and Energy (BMWi) for funding the activities which formed the basis for this paper. The authors are solely responsible for the contents and the conclusions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Responsible editor: Walter Klöpffer
Rights and permissions
About this article
Cite this article
Frischknecht, R., Wyss, F., Büsser Knöpfel, S. et al. Cumulative energy demand in LCA: the energy harvested approach. Int J Life Cycle Assess 20, 957–969 (2015). https://doi.org/10.1007/s11367-015-0897-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11367-015-0897-4