Time-Variable Production of Ammonia with Dominant Renewable Energy Supply

In energy research and policy there is a big effort to achieve a large penetration of renewable energy generation, predominantly wind and solar. There exist scenarios with complete transition to such sources within few decades. Energy demand is time-variable and renewable energy sources are inherently also time-variable. These variations occur both at the seasonal and hourly level and result in large fluctuation of electricity price. In this contribution we consider the time-variable production of ammonia which is energy intensive. This essentially treats ammonia not only as the product of a chemical manufacturing plant but also as an energy storage medium. The focus is the optimal design and operation of an ammonia plant coupled to a concentrated solar power plant. We develop a technoeconomic model accounting for the process dynamics and the capital and production costs. We consider two scenarios, namely on-grid and off-grid operation and compare with different energy storage options.