30 October, 2018
If the future is going to be powered by renewable energy, the world needs to get a lot better at dealing with one very precious element, the Materialise conference on sustainability in Wellington has heard.
The argument goes something like this: To fight climate change, the world needs to convert to technology that runs on clean, renewable energy, rather than fossil fuels. If we have windmills instead of coal fired power plants, and electric cars rather than gas-guzzlers, then we’ll dramatically reduce emissions, be able to maintain our quality of life, and stave off the worst effects of climate change.
The problem with that is that with current technology, the strategy relies incredibly heavily on an element that we don’t have all that much of left – lithium. It’s in pretty much every smartphone and electric car battery, and is a vital component of the batteries that make renewable energy a reliable source, by storing up power when the sun is shining or the wind is blowing, and then releasing it when that’s not happening. There’s no shortage of sunlight and wind in New Zealand, but with four seasons often cramming into one day, it’s not consistent. That makes battery storage either a limiting or enabling factor in creating a reliable renewable energy supply.
Use of lithium as the ingredient that powers batteries has skyrocketed in the space of a few decades, and accordingly, the price of lithium has shot up as well. The reason is it’s tricky to produce – about half of it takes place in Chile, through a slow process of brine containing lithium being evaporated by the sun. And that’s a difficult process to scale up dramatically, which means the demand for lithium will really start to stretch the supply. And if it can’t be met, then that means dreams like a fully electric vehicle fleet, are just that – dreams.
The element needed for an electrified future was a vital part of two of the keynote speakers at the Materialise conference at Te Papa in Wellington. The keynote speakers were invited based on their work in coming up with new technological innovations at the ‘discovery end’ of the scientific method. The questions being asked around batteries were twofold: what if there were better ways to increase the supply of lithium? And what if, once that had been secured, there were better ways to use it?
Dr Anita Hill, the Executive Director of Future Industries at the Commonwealth Scientific and Industrial Research Organisation in Australia, was the first of the keynote speakers to raise the topic of lithium. With an eye to the industrialised, digitised society we live in, she spoke about the fundamental relationships between water and material use, energy consumption and economic activity, and how that meant a more sustainable circular economy needed to be built.
Dr Hill’s research focused on what she described as a “recycling bin of the future,” which would operate at a molecular level. It would use metal-organic framework membranes to filter out ions like sodium and lithium from water. Such technology could revolutionise processes like desalination of salt water, so that it can become safe for human use. It would also, somewhat ironically, be applicable to the wastewater created by the mining and oil extraction process known as fracking. Dr Hill acknowledged that it’s strange to consider an environmentally destructive process, which produces carbon emissions through fossil fuels, could have beneficial offsets. But she stressed that research should continue into the area to get it to the point where it could be scaled up to industrial levels, so that some environmental good could come out of fracking.