Steel Circularity in NZ; The Pathway to Net Zero

Yeah, and we'll jump right into it as well, right? So when you started mapping the flows through steel within New Zealand's economy, what was the finding that kind of really surprised you?

Sure.

So a big part of the research was conducting a material flow analysis.

And this was the starting point, I suppose, to get some quantitative data that I'd use for the qualitative aspects of the research later.

And I wanted to get a clear picture of steel flows and stocks in New Zealand.

And I think some of the numbers themselves that came out of that process were really interesting.

So, for example, New Zealand has approximately 52 million tons of steel and use in stocks and 28 million of those in buildings and infrastructure.

And the other 24 million is in other industries such as vehicles, packaging, etc.

And if you divide that by the population, that's roughly 10 tonnes per person.

So every New Zealander has 10 tonnes of steel, essentially, to their name, which hopefully means that steel becomes something important for the wider population.

And I think it's pretty cool to be able to put an approximate number on New Zealand steel stock size.

And then an important part of the research was using that material flow analysis to estimate our scrap exports.

So I knew we exported scrap, but I hadn't appreciated the scale until the numbers came together.

And we're sending about 600 kilotons of scrap overseas every year, which is actually similar to what New Zealand steel produces domestically.

And then my goal for the research was to visualize that into a Sankey diagram, which is quite an interesting way to see how those flows and stocks combine together.

And you can start to see the inefficiencies and opportunities, things like the mining of iron sand on one end, how we smelt it through coal-based processes to make crude steel.

And then on the other end with the scrap steel, how we ship that off to places like Bangladesh, India, Singapore, Australia, for example, to be melted down, often on dirtier grids than ours.

And what does it really cost to even ship those out?

There's two costs, right? There's the carbon cost and the monetary cost.

So I was mostly looking at the carbon cost, which I think is quite interesting.

So a big part of this research was after working out the material flows, putting emissions factors to each of those.

And the idea is we could take one kiloton of scrap steel that was exported and and work out what was the cost.

So one benefit of an electric arc furnace in New Zealand is that scrap steel that used to be exported overseas and melted down elsewhere, we obviously melt down in New Zealand.

And some of the savings there come from the renewable aspect of our grid, but a key part that's often overlooked is the transport emissions, which can be relatively significant.

Yeah, and before we jump into New Zealand steel EAF as well, because New Zealand currently produces it through a very carbon intensive process.

Yeah, and we'll jump right into it as well, right? So when you started mapping the flows through steel within New Zealand's economy, what was the finding that kind of really surprised you?

Sure.

So a big part of the research was conducting a material flow analysis.

And this was the starting point, I suppose, to get some quantitative data that I'd use for the qualitative aspects of the research later.

And I wanted to get a clear picture of steel flows and stocks in New Zealand.

And I think some of the numbers themselves that came out of that process were really interesting.

So, for example, New Zealand has approximately 52 million tons of steel and use in stocks and 28 million of those in buildings and infrastructure.

And the other 24 million is in other industries such as vehicles, packaging, etc.

And if you divide that by the population, that's roughly 10 tonnes per person.

So every New Zealander has 10 tonnes of steel, essentially, to their name, which hopefully means that steel becomes something important for the wider population.

And I think it's pretty cool to be able to put an approximate number on New Zealand steel stock size.

And then an important part of the research was using that material flow analysis to estimate our scrap exports.

So I knew we exported scrap, but I hadn't appreciated the scale until the numbers came together.

And we're sending about 600 kilotons of scrap overseas every year, which is actually similar to what New Zealand steel produces domestically.

And then my goal for the research was to visualize that into a Sankey diagram, which is quite an interesting way to see how those flows and stocks combine together.

And you can start to see the inefficiencies and opportunities, things like the mining of iron sand on one end, how we smelt it through coal-based processes to make crude steel.

And then on the other end with the scrap steel, how we ship that off to places like Bangladesh, India, Singapore, Australia, for example, to be melted down, often on dirtier grids than ours.

And what does it really cost to even ship those out?

There's two costs, right? There's the carbon cost and the monetary cost.

So I was mostly looking at the carbon cost, which I think is quite interesting.

So a big part of this research was after working out the material flows, putting emissions factors to each of those.

And the idea is we could take one kiloton of scrap steel that was exported and and work out what was the cost.

So one benefit of an electric arc furnace in New Zealand is that scrap steel that used to be exported overseas and melted down elsewhere, we obviously melt down in New Zealand.

And some of the savings there come from the renewable aspect of our grid, but a key part that's often overlooked is the transport emissions, which can be relatively significant.

Yeah, and before we jump into New Zealand steel EAF as well, because New Zealand currently produces it through a very carbon intensive process.