Electricity cost and CO2 savings potential for chlor-alkali electrolysis plants: Benefits of electricity price dependent demand response

Chlor-alkali electrolysis plays a significant role in Germany's electricity demand, with a share of >2%. It offers a promising avenue for leveraging demand response strategies. In times of escalating electricity prices, load shifting can help to maintain economic competitiveness of domestic industries. This study aims to assess the potential for electricity cost savings and related CO2 emission reductions through optimal load shifting practices for chlor-alkali electrolysis, considering both current and projected future electricity prices. The research employs the mixed-integer energy system modeling framework IRPopt to model and optimize a chlorine value chain under various scenarios. A sensitivity analysis is conducted to identify the primary factors driving electricity cost savings. The findings reveal that, based on the 2019 electricity price distribution (before pandemic and energy crisis), load shifting can yield electricity cost savings of 5.8% and CO2 emission reductions of 2.7%. As the share of variable renewable energy sources increases along with other driving factors, the electricity price spread is projected to rise from 28% in 2019 to an average of 87% in 2040 scenarios. Consequently, electricity cost savings rise up to 22% and CO2 emission reductions up to 10%. The primary drivers behind electricity cost savings include electricity price spreads and the utilization and operating range of the electrolyzer. In addition to the business-level advantages, the resulting decrease in residual load and lower CO2 emissions contribute to the integration of variable renewable energy sources and the achievement of decarbonization targets at the economic level.