Simulation of the optimal plant size to produce renewable hydrogen based on the available electricity

Abstract

Renewable hydrogen is emerging as a valid energy alternative to the fossil fuels currently in use. Governments are developing hydrogen-based energy strategies as a tool to decarbonise the transport, industrial, energy, and residential sectors. It is estimated that by 2050, hydrogen could cover 34% of the energy demand in these sectors in Europe according to the European Commission. However, for this to happen, green hydrogen must be produced on a large scale and in an economically feasible way.The aim of this project is to model any given renewable electricity generation system so that resources are optimized to achieve the highest and most cost-effective hydrogen production possible. Based on the green energy available data available and the characteristics of the electrolysers considered, the model minimises the cost per kilogram of hydrogen produced by optimising the size of the electrolyser.Once boundary conditions were set for two renewable energy generation cases and hydrogen production was determined for an average year, the profitability was calculated as a function of two variables: electrolysis plant size and hydrogen selling price. In the case of offshore wind power, it becomes profitable to produce hydrogen starting at a selling price of $5.5/kg H2, with a minimum plant size of 55 MW.With solar photovoltaic electricity as the input of the electrolysis plant in the second scenario, for plant size range of 1 MW–300 MW, the economic balance becomes positive selling at $3.5 to $7 per kg of hydrogen produced. The results are discussed more in depth throughout the article based on the simplified calculus model presented.