Techno-economic evaluation of two hydrogen supply options to southern Germany: On-site production and import from Portugal

Hydrogen production through electrolysis using renewable electricity is considered a major pathway and component for a sustainable energy system of the future. For this production pathway, a high renewable energy potential, especially in solar energy, is crucial. Countries like Germany with a high energy demand and low solar potential strongly depend on hydrogen import. In the present work, a case study with two alternative hydrogen supply options is conducted to evaluate the economic viability of solar hydrogen delivered to a hydrogen pipeline in Stuttgart, Germany. For both options, hydrogen is generated through an 8 MW alkaline electrolyser, solar powered and supported by grid-based electricity to meet the required load. The first option is based on a hydrogen production system that is positioned in Sines, Portugal, an area with high global radiation and proximity to a deep sea port. The hydrogen is processed by liquefaction and transported to Stuttgart by tanker ship via Hamburg and by truck. The second supply option uses an on-site hydrogen production system in Stuttgart.The work shows that the production costs in Sines with 2.09 €/kgH₂ (prices in €₂₀₂₁) are, as expected, significantly lower than in Stuttgart with 3.24 €/kgH₂. However, this price difference of 1.15 €/kgH₂ for hydrogen production drops to a marginal difference of 0.13 €/kgH₂ when considering the whole value chain to the delivery point in Stuttgart. If the waste heat from electrolysis is used in a district heating system in Stuttgart, the price difference is down to 0.03 €/kgH₂. The first supply option is dominated by costs for processing, especially liquefaction. These costs would need to be reduced to fully exploit the cost advantage of solar hydrogen production in Portugal. Also, a fundamental switch to pipeline transport of gaseous hydrogen should be considered. Both investigated hydrogen supply options show the potential to provide the pipeline in Stuttgart with hydrogen at lower costs than by using the alternative technology of steam reforming of natural gas.