When the aluminium smelter at the bottom of the South Island shuts up shop, there'll be enough sustainable, carbon-friendly hydro-electricity to power a major city going spare. So what should New Zealand do with it? Physics professor and nanotechnologist Nicola Gaston has some surprising suggestions.

The One Hot Minute podcast is a companion series to Stuff's One Hot Minute video series, in which guests get just 60 seconds to deliver their big idea about climate change. Then in this podcast we dig deeper into that idea.

To watch the videos, see www.stuff.co.nz/onehotminute. The series is part of Stuff's Forever Project.