Have a read in todays herald
https://www.nzherald.co.nz/business/...T5HCRRD6423WY/
The last part discusses producing hydrogen in NZ. What is already happening and plans for the future, although currently you might be right about it being imported.
Genesis may not be the best company to do it as hydrogen is only "green" when produced from renewable energy such as hydro, geothermal, wind etc.