Comparative Life Cycle Assessment of Demand-Side Management via Operational Optimization

Abstract

Due to the volatile nature of renewable energy sources, balancing electricity generation and consumption in electric power systems becomes more challenging with an increasing share of renewable generation technologies. A promising option to face fluctuations in the electricity grid is demand-side management (DSM), the adjustment of electricity consumption driven by varying electricity prices. To assess the environmental impacts of DSM, the holistic method of life cycle assessment can be applied. In literature, life cycle assessment of DSM receives increased attention. However, the goals of operating DSM are not consistently reflected in the definition of the functional unit. In our view, the goals of DSM include both the original products of a process as well as the flexible electricity consumption. So far, no approach exists that considers both goals in the functional unit. This work aims to close this gap by developing an approach that jointly considers products and flexibility in the functional unit of DSM. We compare DSM with a steady-state operation of the process as a reference system, given that both systems provide the same products. Furthermore, we expand the reference system with energy storage technologies, which enable short- and long-term flexibility in electricity consumption. We demonstrate the proposed approach on the switchable chlor-alkali electrolysis, using hourly electricity prices and emission factors. Our findings show that comparing the switchable electrolysis to the reference system indicates only small differences in the environmental impacts. Thus, the results indicate that the flexible operation of the chloralkali electrolysis has comparable environmental impacts as integrating electricity storage.