Energy system analysis of marginal electricity supply in consequential LCA
Background, aim and scope
This paper discusses the identification of the environmental consequences of marginal electricity supplies in consequential life cycle assessments (LCA). According to the methodology, environmental characteristics can be examined by identifying affected activities, i.e. often the marginal technology. The present ‘state-of the-art’ method is to identify the long-term change in power plant capacity, known as the long-term marginal technology, and assume that the marginal supply will be fully produced at such capacity. However, the marginal change in capacity will have to operate as an integrated part of the total energy system. Consequently, it does not necessarily represent the marginal change in electricity supply, which is likely to involve a mixture of different production technologies. Especially when planning future sustainable energy systems involving combined heat and power (CHP) and fluctuating renewable energy sources, such issue becomes very important.
Materials and methods
This paper identifies a business-as-usual (BAU) 2030 projection of the Danish energy system. With a high share of both CHP and wind power, such system can be regarded a front-runner in the development of future sustainable energy systems in general. A strict distinction is made between, on the one hand, marginal capacities, i.e. the long-term change in power plant capacities, and on the other, marginal supply, i.e. the changes in production given the combination of power plants and their individual marginal production costs. Detailed energy system analysis (ESA) simulation is used to identify the affected technologies, considering the fact that the marginal technology will change from one hour to another, depending on the size of electricity demand compared to, among others, wind power and CHP productions. On the basis of such input, a long-term yearly average marginal (YAM) technology is identified and the environmental impacts are calculated using data from ecoinvent.
The results show how the marginal electricity production is not based solely on the marginal change in capacity but can be characterised as a complex set of affected electricity and heat supply technologies. A long-term YAM technology is identified for the Danish BAU2030 system in the case of three different long-term marginal changes in capacity, namely coal, natural gas or wind power.
Four analyses and examples of YAMs have been used in order to present examples of the cause–effect chain between a change in demand for electricity and the installation of new capacity. In order to keep open the possibilities for further analysis of what can be considered the marginal technology, the results of four different situations are provided. We suggest that the technology mix with the installation of natural gas or coal power plant is applied as the marginal capacity.
The environmental consequences of marginal changes in electricity supply cannot always be represented solely by long-term change in power plant capacity, known as the long-term marginal technology. The marginal change in capacity will have to operate as an integrated part of the total energy system and, consequently, in most energy systems, one will have to identify the long-term YAM technology in order to make an accurate evaluation of the environmental consequences.
Recommendations and perspectives
This paper recommends a combination of LCA and ESA as a methodology for identifying a complex set of marginal technologies. The paper also establishes values for Danish marginal electricity production as a yearly average (YAM) that can be used in future LCA studies involving Danish electricity.
KeywordsConsequential LCA Danish electricity Energy systems analysis Marginal electricity Methodology
The work presented in this paper is a result of the research project Coherent Energy and Environmental System Analysis (CEESA), partly financed by The Danish Council for Strategic Research.
- Kofoed-Wiuff A, Lindboe HH, Togeby M (2007) Hvor ender vindmøllestrømmen? Naturlig Energi 29(11):16–18Google Scholar
- Dones R, Ménard M, Gantner U (1998) Choice of electricity-mix for different LCA applications. Brussels, BelgiumGoogle Scholar
- ecoinvent (2004) ecoinvent, ecoinvent data v1.3. Final reports ecoinvent 2000 no. 1-15. Swiss Centre for Life Cycle Inventories, DübendorfGoogle Scholar
- Frees N, Weidema BP (1998) Life cycle assessment of packaging systems for beer and soft drinks. Energy and transport scenarios. Miljoestyrelsen (Danish EPA), CopenhagenGoogle Scholar
- Hauschild M, Wenzel H (1998) Environmental assessment of products—volume 2: scientific background. Chapman and Hall, LondonGoogle Scholar
- Lund H (2003) Flexible energy systems: integration of electricity production from CHP and fluctuating renewable energy. International Journal of Energy Technology and Policy 1(3):250–261Google Scholar
- Lund H (2007a) EnergyPLAN—Advanced energy systems analysis computer model—Documentation version 7.0. Aalborg University, Aalborg, Denmark. http://www.energyPLAN.eu
- Lund H, Andersen AN (2004) Optimising small CHP-plant performance in a competitive market: comparing Russia and Denmark. Conference Proceedings, 2nd Russia Power Conference and Exhibition, Moscow, 10–11 March 2004Google Scholar
- Lund H, Mathiesen BV (2006a) Ingeniørforeningens Energiplan 2030—Tekniske energisystemanalyser, samfundsøkonomisk konsekvensvurdering og kvantificering af erhvervspotentialer. Baggrundsrapport (Danish Society of Engineers’ Energy Plan 2030). Danish Society of Engineers (Ingeniørforeningen Danmark), CopenhagenGoogle Scholar
- Lund H, Mathiesen BV (2006b) Ingeniørforeningens Energiplan 2030—Tekniske energisystemanalyser, samfundsøkonomisk konsekvensvurdering og kvantificering af erhvervspotentialer. Baggrundsrapport (Danish Society of Engineers’ Energy Plan 2030). Danish Society of Engineers (Ingeniørforeningen Danmark), CopenhagenGoogle Scholar
- Mathiesen BV, Münster M, Fruergaard T (2007) Energy system analyses of the marginal energy technology in life cycle assessments. SETAC Europe 14th LCA Case Studies Symposium, Göteborg, Sweden, pp 15–18Google Scholar
- Münster M (2007) Use of waste for heat, electricity and transport—challenges when performing energy system analysis. Proceedings from 4th Dubrovnik Conference on Sustainable Development of Energy, Water and Environment Systems. Dubrovnik, CroatiaGoogle Scholar
- Schmidt AC, Jensen AA, Clausen AU, Kamstrup O, Postlethwaite D (2004) A comparative life cycle assessment of building insulation products made of stone wool, paper wool and flax. Part 1: background, goal and scope, life cycle inventory, impact assessment and interpretation. Int J Life Cycle Assess 9(1):53–66CrossRefGoogle Scholar
- Simapro (2007) SIMAPRO 7.1 Pre Consultants: Amersfort. The Netherlands. www.pre.nl
- The Danish Ministry of Transport and Energy (2005) Energy Strategy 2025—perspectives to 2025 and draft action plan for the future electricity infrastructure. The Danish Ministry of Transport and Energy, CopenhagenGoogle Scholar
- Thrane M (2004) Environmental impacts from Danish fish products—hot spots and environmental policies. PhD dissertation, Department of Development and Planning, Aalborg UniversityGoogle Scholar
- Weidema B (2003) Market information in life cycle assessment. Environmental Project No. 863. Danish Environmental Protection Agency, CopenhagenGoogle Scholar
- Wenzel H, Hauschild M, Alting L (1997) Environmental assessment of products—volume 1: methodology, tools and case studies in product development. Chapman and Hall, LondonGoogle Scholar