Hi EarthCitizen,
I work in resource management, which is the NZ version of urban and environmental planning. I've also been a wind farm developer in the UK and have worked on geothermal/hydro here in New Zealand. Firstly, good luck with your plans to re-train and for the move, wish you the best. Glad to hear you are passionate about climate change, usually people who are commercial airline pilots accept that they work in a highly unsustainable industry, great to see you are hoping to make a transition to address that, very cool. New Zealand has about 84% of its electricity come from renewable sources, there is still some way to go to totally de-carbonise the economy and tackle the remainder of the energy mix reliant on hydrocarbons.
So to jump right in. If you aren't interested in studying engineering which really is the go-to for hydro schemes and geothermal, there are only a few ways to work in the renewable energy industry:
- Ecology (broad)
- Hydrogology
- Physical Geography
- Geology
- Environmental Science
- Resource Management and Planning
- Possibly others, worth researching and considering your own interests
Note: New Zealand is having a massive reform of freshwater management, to focus on freshwater quality. There is very little chance of there being any new hydroschemes for quite some time. Onshore wind is slow and steady, there has been spatial opportunity mapping on the west coast for offshore wind, there isn't much movement on developing at the moment. Tidal is minimal. Solar is pretty average. Geothermal is usually undertaken by local iwi (Māori tribes), haven't personally seen private developers in that sphere. Hydrogen is probably the most anticipated renewable energy resource likely to be expanding over the next couple of years, especially as there is a big move to de-carbonise transport towards the current 2050 goal. I would probably research what roles may come out of the green hydrogen industry, as more renewables will be needed for the electrolysis process. It isn't a barrier to living in the North Island, but most of NZ's renewable energy generation is in the South Island. If you are passionate about other aspects of climate change, sea level rise, managed retreat, indigenous biodiversity, pest control, forestry, natural hazard and disaster planning are other growing areas which you could consider. I would also advise looking at the skill shortage list in New Zealand to project future demand for certain skills/qualifications.
Personal note, just study what you are interested in, also maybe monitor NZ news for when they are planning on re-opening to international students as I know they are keen to do it... but may be unlikely to 2021
Hope this helps.