08:30 R. Camilla ThomsonGareth P. Harrison and John P. Chick

The Impact of Practitioner Decisions on LCA for Marine Energy Converters

ABSTRACT. The LCA methodology is designed to be used for a wide range of applications, but this flexibility introduces considerable scope for variation in results. This is a particular issue in the marine renewable energy industry, where estimates of the Global Warming Potential (GWP) and energy return on investment inform policy maker and investor decisions. Although existing papers have identified the specific limitations of LCA [1-4], few have attempted to quantify the effects of individual assumptions and methodological choices.

A number of carbon and energy audits of Marine Energy Converters (MECs) have been carried out at the University of Edinburgh, and recent work has taken the raw data from some of these studies and expanded them to full LCAs with comprehensive sensitivity analyses [5-8]. Access to the original calculations, each carried out by a different person, allows the impact of different practitioner choices to be examined in detail and quantified. One such review was presented in [9] and further refined in [8], using the Pelamis Wave Energy Converter as a case study. This paper further expands this work to include a second case study of the Seagen tidal current turbine [5, 7], identifying the key sources of variation in the results, with particular reference to LCA methodology and selection of life cycle impact assessment method. The principal aim of this work is to provide recommendations on best practice for LCA of MECs, and potentially inform LCA studies of all types of renewable energy converter.

A preliminary review of the results focuses on the GWP and energy intensity, finding that variations between studies are typically 17 to 33%, but as much as 1027% in the case of the GWP of the Seagen [5, 7]. The most significant variations are expected to be due to the applied recycling allocation method, differences in LCI data source, and chosen characterisation factors. This work will quantify the contribution of each of these key choices to the variation in results, examine variation in other impact categories, and provide recommendations for future analyses to maximise comparability.


1. Price, L. and A. Kendall, Wind Power as a Case Study. Journal of Industrial Ecology, 2012. 16: p. S22-S27. 2. Davidsson, S., M. Höök, and G. Wall, A review of life cycle assessments on wind energy systems. The International Journal of Life Cycle Assessment, 2012. 17(6): p. 729-742. 3. Finkbeiner, M., Carbon footprinting – opportunities and threats. The International Journal of Life Cycle Assessment, 2009. 14(2): p. 91-94. 4. Schreiber, A., P. Zapp, and J. Marx, Meta-Analysis of Life Cycle Assessment Studies on Electricity Generation with Carbon Capture and Storage. Journal of Industrial Ecology, 2012. 16: p. S155-S168. 5. Douglas, C.A., G.P. Harrison, and J.P. Chick, Life cycle assessment of the Seagen marine current turbine. Proc IMechE Part M: J. Maritime Environment, 2008. 222(M1): p. 1-12. 6. Parker, R.P.M., G.P. Harrison, and J.P. Chick, Energy and carbon audit of an offshore wave energy converter. Proc. IMechE Part A: J. Power and Energy, 2007. 221(A8): p. 1119-1130. 7. Miliara, D., Full Life Cycle Assessment of a Tidal Current Turbine (Seagen), in School of Engineering. 2013, University of Edinburgh. 8. Thomson, R.C., Carbon and Energy Payback of Variable Renewable Generation, in School of Engineering. 2014, University of Edinburgh: Edinburgh. 9. Thomson, C., G. Harrison, and J. Chick. Life Cycle Assessment in the Marine Renewable Energy Sector. in LCA XI. 2011. Chicago, USA.

08:45 Roberta Graf and Michael Held

Resource Availability from a LCA perspective – Method development to enable decision support

ABSTRACT. The scarcity of resources, political, economic or geological induced, is gaining importance for today´s society and the affiliated industries. This fact is highlighted by the attention the topic attracts of several governmental bodies including the EU and the US. The former identifies critical raw materials for its industries and develops approaches [1]. Rare earth elements are one example for listed raw materials because of their economic importance whilst facing environmental country and supply risk [2]. Future material or technology decisions should be based on sound information about the availability of the resources inclined. Existing methodologies need to be extended to cover all relevant aspects.

The German Mineral Resources Agency observes not only geological information but tends to cover larger parts of the value chain [3]. The presented method aims to broaden this approach by including further information, as for example recycling rates. The goal is to evaluate the sustainability of choices with a focus on the future viability. An identification of indicators and parameters, describing the availability of resources and their temporal range, is the first step. It bases on a literature review of existing methodologies. Furthermore typical value chains are modularized analog to the procedure of LCA modeling. Benchmarks are then assigned for the modularized subparts and the prior identified parameters. A generic material flow analysis (MFA) model is appropriate for the dynamic character of resource availability. The model implements the mentioned parameters. Via scenario technics the assigned benchmarks are used to evaluate the MFA model dynamical. The dynamic MFA model can thereby later be applied to evaluate the sustainability of material or technology choices.

The presentation will discuss a methodological approach to evaluate future availability of resources beyond the consideration of the scope of geological stock. An outline of the envision method will be presented as well as first results for the modularization and the setting of the benchmarks.

The illustrated approach will establish a reliable tool to analyze the sustainability of choices which are made on a regular basis in industries worldwide. It serves as a safeguard for decision makers as early as in their product development phase.

[1] EC: Report on Critical Raw Materials for the EU. Report of the Ad hoc Working Group on defining critical raw materials. 2014. [2] Oakdene Hollins & Fraunhofer ISI: Study on Critical Raw Materials at EU Level. Final Report. 2013 [3] DERA: Dera-Rohstoffliste 2014. Angebotskonzentrationen bei mineralischen Rohstoffen und Zwischenproduktenpotenzielle Preis– und Lieferrisiken. 2015

09:00 Marlene PreißMieke Klein and Andreas Genest

Adding value to your LCA by Material Flow Cost Accounting

ABSTRACT. Life Cycle Assessment (LCA) [1] is frequently used in a number of companies. While it is a suitable tool to identify optimization potentials from the environmental perspective, it can also be combined with Material Flow Cost Accounting (MFCA) to complement the analysis with an economic perspective.

Many of these LCAs are initiated by the sustainability department. Oftentimes, LCA is applied to use results for communication, to quantify and decrease environmental impact and in order to document responsible behavior. While they are costly as they are time-consuming, only few companies have realized that conducting an LCA can provide the foundation for further economic assessment. In case that a material flow network was set up to conduct the LCA and the software in use supports MFCA, this method can easily be implemented. Traditional cost accounting allocates waste handling costs to the products. MFCA (as described in [2]) calculates the true costs of waste by allocating all costs caused by material losses on these. This includes not only waste handling, but also their share in material costs and processing costs. To enable this, it is important to handle material losses as (unintended) byproducts.

The case study of a metal processing company will be presented. For one small metal component, the eight processing steps were modeled and analyzed. Initially, a LCA was conducted and hotspots of environmental impact identified. Subsequently, costs for material, energy, labor and hourly rates for the machines were included (preliminary results presented at [3]). Two processes caused the majority of material loss. Even though the second process step caused roughly twice as much material loss as the sixth process step, the latter contributes more than double of the costs.

This example shows how the combination of LCA and MFCA provides a solid foundation for comprehensive decision-support.

[1] ISO 14040 (2006): Environmental management – Life cycle assessment – Principles and framework, International Organisation for Standardisation (ISO), Geneve. [2] ISO 14051 (2011): Environmental management – Material flow cost accounting – General framework, International Organisation for Standardisation (ISO), Geneve. [3] Preiß, Marlene (2014): Material Flow Cost Accounting in Umberto using the example of a metal processing company. Oral Presentation at Umberto User Workshop, Hamburg.

09:15 Silvia Elena Solano Quesada and Edgar Ortíz Malavassi

Carbon Footprint of buildings in the Costa Rican context: A case study using a partial life cycle approach

ABSTRACT. Several international methodologies provide detailed guidelines for quantifying the carbon footprint of a product and can be applied to assess the life cycle of a building (LCA). However, these procedures have not yet been tailored to fit conditions in Costa Rica, a country that seeks to be a low emissions economy.

The objectives of this study were: a) to analyze existing LCA methodologies in order to identify which is the best suited for the Costa Rican building sector, b) to prepare a spreadsheet tool to calculate the partial carbon footprint of any building project using the selected procedure, and finally c) to apply it to a building case.

The ISO/TS 14067:2013 Carbon Footprint of products-Requirements and guidelines for quantification and communication was the selected methodology. It was adjusted to local conditions and it was applied to Trópika, a habitation module designed and built for the Solar Decathlon Europe 2014 by students of the Instituto Tecnológico de Costa Rica.

A partial LCA from cradle to construction was conducted for the Trópika house unit. The estimated embodied carbon was 28 tons CO2e for the 81 m2 house, or 345 kg CO2e per m2 of useable floor area. Carbon fixation was 15 tons of CO2e, and the final balance was 13 tons of CO2e. The building materials made up 80% of the total embodied carbon. Metals and timber accounted for 40% and 22% respectively of the total. Regarding the total mass of the module (kg), metals and timber accounted 21% and 53% respectively. These results were validated by comparing them with those obtained in other tools such as SimaPro V7.3.3 as well as data in literature.

As one of the economic engines, the building sector needs to align itself with the country’s goal of achieving carbon neutrality by 2021. This study, as the first of its kind in the country, introduces one easy to use tool to identify baseline conditions and to be used as a decision making tool to reduce greenhouse gas emissions generated by the sector. The benefit is to create measurable, verifiable and comparable data to analyze and improve construction processes.