Lithium needed for battery storage systems might one day be extracted from calderas surrounding dormant supervolcanoes
In order to rely on renewable energy sources like wind and solar power, the world is going to have to find efficient ways to store electricity, saving it up for times when the wind is not blowing and the sun is not shining.
One of the leading contenders for large-scale storage at the moment is the lithium ion battery. Elon Musk has promised to build a 100MW batteryin Australia, and energy company AES is constructing a facility of the same size in LA.
Currently, most of the lithium used in these batteries comes from Australia and Chile. But the lithium supply needed to provide large-scale battery storage could come from an unexpected place, according to a new study. Supervolcanoes
"We're going to have to use electric vehicles and large storage batteries to decrease our carbon footprint," co-author, professor Gail Mahood, said. "It's important to identify lithium resources in the US so that our supply does not rely on single companies or countries in a way that makes us subject to economic or political manipulation."
The Stanford team has come up with a new technique to detect lithium in volcanic lakes that have appeared in calderas – holes in the ground that were created when supervolcanoes erupted, displacing huge quantities of lava.
Lithium, found in the volcanic deposits, has been drawn out into the lake over thousands of years, and gathered as a clay in the lake. But some lakes are more lithium-rich than others, depending on the original magma content, and the key is being able to identify which ones.
“Because lithium is a very volatile element, it is extremely difficult to measure,” Tom Benson, lead author of the study, says. “You can't simply measure the whole-rock chemical composition of a volcanic rock, like volcanologists typically do.”
Instead, the team worked out a way to identify how much lithium was in the lake. By extracting tiny blobs of magma that had been trapped in crystals, heating them up and quenching them, Benson could identify the lithium content in the magma.
The process was fiddly and time-consuming, but it helped reveal a simpler way to find lithium. “What this research shows is that the zirconium content of the magmas show a nearly linear relationship with lithium,” says Benson. “When the lithium content of the magma is high, the zirconium content is low, and vice-versa.” And zirconium is much easier to measure because it is non-volatile.
The study was based in the US, but the whole world will be facing similar challenges in the future. For example, in the UK, “the grid-connected energy storage market is expected to expand from total installed capacity of 3 GW at the end of 2016 to 28 GW by 2022,” Marek Kubik, a market director for energy storage systems at AES, says.
“It’s a neat study and very interesting,” adds professor Stephen Piercey, from the Memorial University of Newfoundland, who was not involved in the study. “Their use of micro chemical methods provide a means of documenting what types of volcanoes may have been enriched in lithium, and by association what supervolcanic environments might have the potential for lithium redistribution... as potential sources for lithium extraction.”
People living around volcanoes, in places like Iceland, have been harnessing their energy for over a hundred years, using steam from geothermal vents to drive turbines. However, this only works around active volcanoes.
“The lithium deposits I discuss in this manuscript only occur in old, dormant volcanoes where the caldera lake has drained and exposed the old lake sediments,” says Benson.
“Geothermal is used to provide the energy, and lithium can store the energy; they are not in competition and can actually really complement each other,” he adds. “I think it is important to use both volcanic resources as we strive to develop a global clean energy portfolio