Energy system analysis for evaluation of sector coupling technologies

Abstract

Presently no technology for long-term storage of surplus of big quantities of electrical energy is available. Polygeneration power plants with energy storage allow re-conversion of produced energy fuels and contribute to the energy supply security for industry and private households. Further the production of bulk chemicals with low carbon dioxide emissions is possible assuming the availability of hydrogen from renewable energy.The outstanding benefit of such polygeneration power plants is the high load flexibility of plant operation. This advantage over other sector coupling technologies is hardly evaluated by common operating figures. To assess these technologies, which allow crosslinking of power generation, fuel and chemical feedstock supply, they were modeled by quasi-dynamical process simulation. By integration of these models in an energy system analysis different energy storage technologies can be rated in a comparative study. An objective and reliable data base is created in this way for a future energy policy design and for strategic investment decisions in industry.Based on published data a simplified model of the German energy system was established with MatlabSIMULINK® and validated on behalf of data for the year 2015. The model is able to reproduce typical phenomena within German energy sector, e. g. merit order principle and formation of electricity rates at European Energy Exchange (EEX). The model can be adjusted to different (future) economic and social scenarios by different parameter settings.In an energy system analysis for 2030 the energy system model was applied to evaluate the impact of the energy transition from fossil to renewable energy supply system of Germany (the so called “Energiewende”) to the German energy system. Simulation results allow conclusions to future situation of energy system, e. g. development of exchange prices for energy caused by rising residual loads.Subsequently the effects of three polygeneration concepts with energy storage in the energy system of 2030 were investigated under equal boundary conditions. Calculations show lower import/export quantities and changed power plant operation times. So power production from lignite decreases while generation by pumped storage power stations rises. Lower import/export quantities indicating electrical grid reliefs.