This study investigates the production of green ammonia using hydrogen produced via water electrolysis, focusing on alkaline electrolysis (AEC) and solid oxide electrolysis (SOEC) technologies. The cost of green ammonia is estimated, considering both current and projected electrolyzer costs, and compared with the cost of "fossil" ammonia synthesized from natural gas. The study finds that while AEC-based green ammonia is currently cheaper, SOEC shows more cost-effectiveness in the future, particularly with projected improvements in electrolyzer technology. By 2050, the cost of green ammonia from an SOEC-based plant is estimated to be 495 €/t, assuming an electricity price of 30 €/MWh. The study also examines the potential for heat integration between the electrolyzer and Haber-Bosch process, which can significantly reduce the cost of green ammonia. Additionally, the impact of CO₂ taxes on the cost parity between green and fossil ammonia is analyzed, showing that a CO₂ tax of 110 €/tCO₂ would make SOEC-based green ammonia cost-competitive even at a high levelized cost of electricity (LCOE) of 60 €/MWh. The study concludes that while AEC is currently more cost-effective, SOEC has the potential to become the preferred technology for green ammonia production in the future.This study investigates the production of green ammonia using hydrogen produced via water electrolysis, focusing on alkaline electrolysis (AEC) and solid oxide electrolysis (SOEC) technologies. The cost of green ammonia is estimated, considering both current and projected electrolyzer costs, and compared with the cost of "fossil" ammonia synthesized from natural gas. The study finds that while AEC-based green ammonia is currently cheaper, SOEC shows more cost-effectiveness in the future, particularly with projected improvements in electrolyzer technology. By 2050, the cost of green ammonia from an SOEC-based plant is estimated to be 495 €/t, assuming an electricity price of 30 €/MWh. The study also examines the potential for heat integration between the electrolyzer and Haber-Bosch process, which can significantly reduce the cost of green ammonia. Additionally, the impact of CO₂ taxes on the cost parity between green and fossil ammonia is analyzed, showing that a CO₂ tax of 110 €/tCO₂ would make SOEC-based green ammonia cost-competitive even at a high levelized cost of electricity (LCOE) of 60 €/MWh. The study concludes that while AEC is currently more cost-effective, SOEC has the potential to become the preferred technology for green ammonia production in the future.