20 th European Symposium on Computer Aided Process Engineering – ESCAPE20 S. Pierucci and G. Buzzi Ferraris (Editors) © 2010 Elsevier B.V. All rights reserved. Carbon footprint assessment of photovoltaic modules manufacture scenario Antonio Dominguez-Ramos, a,b Michael Held, b Ruben Aldaco, a Matthias Fischer, c Angel Irabien a a Department of Chemical Engineering and Inorganic Chemistry, University of Cantabria, Avda. Los Castros s.n., 39005 Santander, Spain, domingueza@unican.es b Department of Life Cycle Engineering, LBP, University of Stuttgart, Hauptstrasse 113, 70771 Echterdingen, Germany c Fraunhofer Institute for Building Physics – Department Life Cycle Engineering, Hauptstrasse 113, 70771 Echterdingen, Germany Abstract The influence of production sites location within process design and optimization is addressed to consider operational costs such as transportation or labor. But when the environmental sustainability of a system product is considered in terms of Life Cycle Assessment, this influence is sometimes minimized due to the lack of reliable data. The impact of grid mix in each echelon within the supply chain of a product can be significant. In this work, it is demonstrated the influence of the location of production sites for photovoltaic solar modules in the final environmental profile, expressed as CO 2 -eq. Results show that the Global Warming metric can be as large as twice when using this global approach. Keywords: Location, grid mix, photovoltaic solar energy, environmental impact, life cycle analysis 1. Introduction Life Cycle Assessment (LCA) has been largely applied in process design and optimization [1]. The LCA methodology is typically considered within optimization problems with environmental constraints, which allows us to consider different topics such as the influence of the production sites location, especially in the relation with the environmental impact related to transport issues. However, the different raw materials coming into a production process can be produced in different countries. When power grid is required in the production of those raw materials, the national country grid mix could influence in the results of the environmental profile of the final product in a relevance way, specially when the product is energy intensive. In this work, as a case study from the photovoltaic (PV) industry, it was considered the impact of the different national grid mixes (global mix) in the environmental profile of PV modules using a LCA approach. Most of LCA studies related to PV solar modules consider specific country grid mix for the origin of the required electricity in almost all the production process along the production chain, being one of the key parameters affecting the environmental profile the grid mix [2]. However, the current global market makes the production sites to be spread along the world. This fact makes that the components that integrate a PV module could be produced in different countries. Therefore, using individual national grid mix to assess the environmental performance of a solar module