Journal of Power Sources 186 (2009) 138–157 Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour Life cycle design metrics for energy generation technologies: Method, data, and case study Joyce Cooper a,∗ , Seung-Jin Lee a , John Elter b , Jeff Boussu c , Sarah Boman c a University of Washington, Department of Mechanical Engineering, Box 352600, Seattle, WA 98195, USA b State University of New York at Albany, Center for Sustainable Ecosystem Nanotechnologies, Albany, NY 12203, USA c Plug Power, 968 Albany Shaker Road, Latham, NY 12110, USA article info Article history: Received 7 August 2008 Accepted 10 September 2008 Available online 27 September 2008 Keywords: Life Cycle Assessment Energy generation Design PEMFC abstract A method to assist in the rapid preparation of Life Cycle Assessments of emerging energy generation technologies is presented and applied to distributed proton exchange membrane fuel cell systems. The method develops life cycle environmental design metrics and allows variations in hardware materials, transportation scenarios, assembly energy use, operating performance and consumables, and fuels and fuel production scenarios to be modeled and comparisons to competing systems to be made. Data and results are based on publicly available U.S. Life Cycle Assessment data sources and are formulated to allow the environmental impact weighting scheme to be specified. A case study evaluates improvements in efficiency and in materials recycling and compares distributed proton exchange membrane fuel cell systems to other distributed generation options. The results reveal the importance of sensitivity analysis and system efficiency in interpreting case studies. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Various emerging energy generation technologies are intended to produce “clean” energy. The definition of “clean” has inter- mittently included negligible or substantially lower operating emissions, consideration of carbon sequestration in bio-based sys- tems, and consideration of hardware recycling (e.g., the application of the “zero-to-landfill” design principle by Plug Power [1] in the design of fuel cell systems). In comprehensive technology assessments, “clean” includes consideration of the environmental impacts of the full technology life cycle. The “life cycle” includes materials and fuels acquisition (e.g., mining and agricultural activities); materials and fuels processing; and technology man- ufacturing, use, maintenance, remanufacturing, and retirement including the ultimate management of materials (e.g., recycling, landfilling, and incineration). Life cycle environmental impacts Abbreviations: PEMFC, proton exchange membrane fuel cell; LCA, Life Cycle Assessment; BEES, Building for Environmental and Economic Sustainability (tool by the U.S. National Institute for Standards and Testing); GREET, Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (tool by the U.S. Depart- ment of Energy’s Argonne National Laboratory); CO 2 , carbon dioxide; CH 4 , methane; CO, carbon monoxide; N 2 O, nitrous oxide; NOx, nitrogen oxides; PM10, particulate matter less than 10 m in diameter; PM2.5, particulate matter less than 2.5 m in diameter; SOx, sulfur oxides; NMVOC, non-methane volatile organic compounds. ∗ Corresponding author. Tel.: +1 206 543 5040; fax: +1 206 5685 8047. E-mail address: cooperjs@u.washington.edu (J. Cooper). include for example resource use (e.g., the use of fossil fuels or land) and contribution to climate change, acidification, or smog formation. The assessment of life cycle environmental impacts for energy generation and other technologies is described by the International Standards Organization’s (ISO’s) Life Cycle Assessment (LCA) stan- dards (in the ISO14040 series [2]). In the ISO LCA process, material and energy use and waste are estimated for each life cycle pro- cess and for the system as a whole (e.g., how much energy is consumed and carbon dioxide is emitted by processes through- out the life cycle). From this energy and materials inventory, the contribution of the life cycle to a variety of environmental impacts is estimated (e.g., how much do the life cycle air emissions con- tribute to global climate change). As technologies move from the laboratory to wide-scale use, knowing the potential life cycle con- tribution to environmental impacts provides valuable insights into the evaluation of design variants, in the comparison to other energy generation technologies, and in meeting corporate, community, and national goals. In addition to protocol standardization, LCA practice has substantially changed since the early 1990s. Practitioners have developed sophisticated software tools and extensive database sys- tems to assist in the preparation of inventory analyses and impact assessments and to interpret the results. However, the use of many of these databases and software tools requires a relatively high level of training and a relatively detailed engineering knowledge of industrial process data and modeling, chemical fate and transport 0378-7753/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2008.09.067