Hydrogen, often referred to as the 'Swiss army knife' of decarbonisation due to its versatility, presents both challenges and opportunities in New Zealand's transition to green hydrogen. The current global demand for hydrogen, primarily produced from fossil fuels, underscores the necessity to shift to emissions-free sources for decarbonisation efforts. Research indicates that New Zealand's green hydrogen demand could range from 1 MT/y to 2.8 Mt/y, with applications like fertiliser, methanol, shipping, and steel production driving this demand. New Zealand would need to significantly expand its renewable power plant capacity and electrolyser installations to meet the growing hydrogen demand. Additionally, long-term energy storage and decarbonising steel production through hydrogen-based processes are crucial focus areas. The prospect of exporting hydrogen adds another layer of complexity, with challenges in transportation logistics and cost efficiency. Various methods, from cryogenic liquefaction to e-methanol production, are being explored to facilitate hydrogen exports. Despite the cost challenges associated with hydrogen production, ongoing research aims to develop low-cost electrolyser technologies using abundant materials. Overall, while hydrogen presents promising decarbonisation solutions, addressing key challenges is essential for maximizing its potential in New Zealand's green transition.