Catálogo de publicaciones - libros

Lightweight design is a major strategy in automotive development. The dominant motivation is a reduction of use-phase energy demands while retaining or improving technical performance. The application of new materials is the prevalent lightweighting strategy. Modern vehicle concepts extend material substitution up to the combination of different materials on a component level, so called hybrid designs. While engineering processes, methods and tools in design and production engineering are well established for conventional designs, hybrid designs pose new challenges. Lightweight materials as well as new manufacturing and recycling processes may cause increased environmental impacts. In order to achieve eco-efficient lightweight structures, energy savings from the vehicles’ use phase need to compensate additional burdens in other lifecycle stages. The current work presents findings gained in a public-private research collaboration. Its starting point is the understanding of the role of life cycle engineering towards its impact on overall sustainability goals. Based on derived key requirements, an integrated life cycle engineering approach is developed. Activities and interfaces between life cycle engineering, component design and manufacturing are elaborated. A special focus is set on the conceptual design stage, as emerging materials and manufacturing technologies lead to a broader concept variety. This stage presents also a major lever for shaping the life cycle environmental impact of components.

The paper provides an overview of how Siemens uses LCA methodology and tools to support cities in the decision-making process to promote sustainable urban transportation systems. It focuses on GHGs and local air pollution. Determining the cause of GHG emissions and air pollution requires flexible scopes and a highly parameterized, hierarchical model, which can be adapted to any city’s transportation system. Emission forecasting capabilities are very important since motorized transportation modes quickly change properties over time. The model screens a large set of infrastructure improvement measures by the click of a button and analyses their impact on KPIs for different years. Applicability, challenges and limits of LCA to the specific application of urban transportation system modelling are discussed.

Construction and demolition waste (CDW) generation, identified as a priority stream by the European Commission, accounts for approximately 25 to 30% of all waste generated in the European Union. According to local specificities (e.g. regulations, waste management organization) best environmental options may differ for transforming waste into new resources. Five oral presentations were given in the session which focused on innovative modelling initiatives combining LCA with complex models in order to improve knowledge for more sustainable urban construction waste management. During the discussions, all participants agreed that re-use or recycling mass performance is a weak and unsufficient indicator for assessing waste management systems. There is an important need for better characterizing stocks and predicting nature and quality of output flows. Geospatialized data combined with Material Flow Analysis was the methodology identified and used by the research community.

Directive 2008/98/EC on waste (WFD) provides that, within 2020, the preparing for re-use and recycling of non-hazardous construction and demolition waste shall be increased to a minimum of 70% by weight. Beginning from a screening of the current percentage of reuse and recycling, type of recycling (types of waste and destinations) and incentive policies in Member States of European Union-28, the research aims to evaluate the effectiveness of the Directive and possible ways of improvement through a Life Cycle based approach. In this paper the incentive policies and some critical issues regarding current regulations are analysed. Further ways to improve legislation are proposed as well as guidelines, which would have an effect on a local level and are aimed at making the recycling of CDW management more effective and sustainable through Life Cycle Management.

In a global context, where several international and national policies attempt to define strategic energy plans that address environmental sustainability, it is necessary to adopt a holistic perspective. In this session, we want to stimulate inputs on how Life Cycle Assessment (LCA) models can capture the complex management challenges in the whole energy sector. In that sense, the various sectors related to energy (namely heat, power, etc.) will become more interrelated, which will be challenging to deal with in Life Cycle Management (LCM). The next decades, LCM modelling of energy systems will have to be quite innovative in order to create realistic models. Furthermore, if LCA wants to do real LCM, the methodology should be widened to e.g. include long-term environmental implications.

When considering the Life Cycle Assessment of an energy-using product, usage is often modelled by average scenarios of use. One challenge of modelling is the availability of data to model the specific scenario in each case. This type of modelling requires the collection of data from several inputs. Also, it can be expensive and time-consuming to collect the specific data to improve the modelling of the use phase. This case study examines a truck refrigeration unit, for which the most environmentally impactful phase is the use phase. The energy consumption of the unit depends on usage. We highlight the importance of modelling a detailed usage scenario specific to each user and examine if it is enough to consider an average usage scenario. This study shows how a specific end-user Life Cycle Assessment and customized recommendation can contribute to improving the global environmental footprint. This is demonstrated by using the energy consumption life cycle inventory analysis of specific end-user behaviour based on experimental data and average scenarios. The results show how far we have to go in the collection of data.

To meet climate and sustainability goals a transition of the system of energy supply and use is needed. However, energy transitions are complex long-term processes and require a variety of methodologies to steer their direction. For this purpose, the combination of environmental, social, economic and technical assessments together with prospective energy scenario modelling is very promising but there are several challenges that need to be addressed to fully benefit from these methodologies. This paper presents the discussions held during a conference session on this issue. The solutions proposed facilitate the combination of energy system modelling frameworks and environmental and social assessments aimed at developing comprehensive prospective studies and feeding information to decision making processes for energy transition toward a low-carbon economy.

The energy supply chain is the backbone of industrialised societies, but it is also one of the leading causes of global environmental burden. Life cycle management (LCM) and life cycle assessment (LCA) are increasingly being used in combination with energy system optimisation models (ESOM) to better represent the energy sector and its dynamics, and facilitate better decision-making. The integration of ESOM and LCA can enable powerful analyses, but not without difficulties. In this chapter, we review studies linking a well-known bottom-up ESOM (TIMES) with LCA databases and identify the principal challenges and how they have been addressed. One of the main integration challenges is the identification of equivalent processes between life cycle inventories and ESOM databases: the mapping problem. Other concomitant issues such as double counting and parameter consistency have been identified and are also investigated.

Access to data on built environment databases makes nowadays possible generating models of the urban spaces to facilitate visualization and analysis of information and synthesize it in sustainability indicators to support urban planning decisions. Life Cycle Assessment (LCA) can greatly benefit from this wealth of potentially available information. The use of LCA data in models developed in Building Information Modelling (BIM) platforms is likely to facilitate the implementation of quantitative environmental assessment in the construction field and their extension, from the building to the city level. Within sustainable urban planning and management, also Nature-Based Solutions (NBS) play a potentially important role, although benefits, co-benefits and costs associated with NBS projects still remain not sufficiently understood. All those aspects have been discussed via the presentation of case studies, proofs of concept and experts’ visions within this session.

Life Cycle Assessment (LCA) is increasingly used for buildings, however, mostly for post-design evaluation of the environmental impact. To use the results for optimization, LCA has to be integrated in the early design stages. While Building Information Modelling (BIM) is more and more applied in detailed design stages, simple 3D models are typically used to compare design variants in early stages. The objective of this paper is to introduce a simplified, design-integrated method based on these early BIM models with limited information. The early BIM-LCA method uses simple 3D geometry and a parametric LCA model. Methodological simplifications are introduced and a single indicator based on the certification system of the German Sustainable Building Council (DGNB) is used to provide an intuitive real-time feedback for the designer. The method is applied to the conceptional design of a residential neighbourhood. The results highlight the great potential of using simplified LCA to quantify environmental performance for decision-making in early design stages.