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Exergy-Efficiency as Enhancement of Energy-Efficiency - an LCA Perspective
Matthias Fischer,* University of Stuttgart - LBP - Department Life Cycle Engineering
Oliver Schuller, University of Stuttgart - LBP - Department Life Cycle Engineering
Stefan Albrecht, University of Stuttgart - LBP - Department Life Cycle Engineering
Michael Faltenbacher, PE INTERNATIONAL GmbHEnergy is one of the main fundaments of today’s industrial societies. But energy resources are not available equally around the world and most of the current utilised energy sources are not unlimited. So the efficient use of energy carriers, the efficient use of end energy and the energy efficiency optimisation along the whole supply chain is required. Also energy represents an increasingly cost intensive resource and energy efficiency helps to save money.
Having a closer look at energy in general, it can be seen that there are different types of energies – thermal energy, mechanical energy, chemical energy. Also there is a quality difference which is expressed by exergy – the working ability of a thermodynamic system.
So exergy-efficiency is energy-efficiency featuring the additional consideration of the quality level of energy. Thus analysing the exergy-efficiency of energy supply chains allows the determination of the eco-efficient way to satisfy current and future energy demands.
By using the methodology of Life Cycle Assessment (LCA) emissions and environmental impacts of energy supply chains can be quantified. Also the environmental advantages of a more efficient use of energy can be quantified. Therewith the additional benefit of an exergy-efficient system can be highlighted and the most environmental friendly energy supply option can be identified.
The presentation will show the different approaches of energy-efficiency and exergy-efficiency and their significant contribution to emission reduction. The method of LCA will thereby be used to quantify the environmental effects and to show the quantitative differences of the approaches and the potential benefit of the special consideration of exergy. The presentation will also show the theoretical background as well as the Life Cycle Assessment perspective on exergy-efficiency.
* corresponding author: matthias.fischer@lbp.uni-stuttgart.de