You are here:
The Unit Emergy Value (UEV) Library for Characterizing Environmental Support in Life Cycle Assessment
Citation:
Arden, S., Cissy Ma, C. De Vilbiss, M. Brown, D. Campbell, AND W. Ingwersen. The Unit Emergy Value (UEV) Library for Characterizing Environmental Support in Life Cycle Assessment. Presented at 11th Biennial Conference Emergy and Environmental Accounting, Gainesville, FL, January 12 - 14, 2023.
Impact/Purpose:
The UEV library provides emergy characterization factors (EmCFs) for different types of renewable energy sources, minerals and metals, land use, water use, biomass, soils, and fossil fuels. The EmCFs rest on a common set of estimates and assumptions regarding geobiosphere processes and were calculated in a dynamic model from the ground up according to consistent algebra, rules and assumptions. The EmCF library will provide a consensus set of emergy values for emergy accounting, LCA and various other analyses.
Description:
Life cycle assessment (LCA) has been extensively used to assess the potential environmental impacts of goods and services over their full life cycles. The traditional environmental impacts in LCA have been focused on impacts of emissions with limited information regarding the impacts of resource uses such as fossil fuel, minerals, land, water and soil. It is critical to not only quantify the impact of uses of these resources in LCA, but capture the environmental inputs to these resources. An environmental accounting method that provides a means of estimating resource value based on the geobiophysical work required to make and sustain those resources is emergy synthesis. Emergy is defined as the available energy of one kind used up to directly and indirectly make and sustain a resource. Emergy values can estimate the value of renewable and nonrenewable resources in a common energy unit (solar emjoule, sej). In this presentation, we will introduce a library of unit emergy values that was developed for quantification of the environmental support associated with elementary resource use in emergy accounting and LCA studies. A complete list of elementary resource flows from two major LCA commercial databases—Ecoinvent v2.2 (Ecoinvent, 2010) and GaBi v4 (PE International, 2010)—were extracted and analyzed. The library provides emergy characterization factors (EmCFs) for different types of renewable energy sources, minerals and metals, land use, water use, biomass, soils, and fossil fuels. The EmCFs rest on a common set of estimates and assumptions regarding geobiosphere processes and were calculated in a dynamic model from the ground up according to consistent algebra, rules and assumptions. Any changes to an underlying estimate or assumption (such as the value of the global emergy baseline) will propagate through the library to update all the factors and avoid any human errors. The EmCF library will provide a consensus set of emergy values for emergy accounting, LCA and various other analyses. The global emergy baseline used in this report is 1.2 E25 seJ/y.