The extent to which renewables ought to dominate Australia’s power grids is a significant difficulty in science and politics. Photo voltaic and wind are clearly now the most affordable type of electrical energy. However limits to those applied sciences can undermine the case for a renewables-only electrical energy combine. The challenges posed by photo voltaic and wind turbines are actual. They’re inherently variable, producing electrical energy solely when the solar is shining and the wind is blowing. To make sure dependable power provides, grids dominated by renewables want “firming” capability: back-up know-how that may provide electrical energy on demand. Some, together with the Albanese authorities, argue gas-fired turbines are wanted to fill the hole. Others, such because the Coalition, say renewables cannot “preserve the lights on” in any respect and Australia ought to pursue nuclear power as a substitute.
However a brand new approach to agency up the world’s electrical energy grids is quick creating: sodium-ion batteries. This rising power storage know-how may very well be a game-changer – enabling our grids to run on 100% renewables.
Sodium-ion batteries: professionals and cons
Power storage collects extra power generated by renewables, shops it then releases it on demand, to assist guarantee a dependable provide. Such services present both quick or long-term (greater than 100 hours) storage.
At current, lithium-ion batteries are the first storage know-how however are greatest for short-term storage. Sodium-ion batteries at the moment are virtually able to fill the long-term storage hole.
Because the title suggests, sodium-ion batteries comprise sodium (image Na), a component present in salt. The know-how includes the motion of sodium ions between constructive and damaging poles, which creates a cost.
The know-how utilized in sodium-ion batteries is much like that of lithium-ion batteries. In actual fact, as others have famous, factories at the moment producing lithium batteries might simply and cheaply transfer to sodium batteries.
And sodium is a much more plentiful materials than lithium, and probably cheaper to extract.
Some sorts of lithium mining require loads of water and power and have led to native air pollution, resembling in South America’s alpine lakes. The air pollution points are far fewer, nevertheless, in Australian hard-rock lithium.
The recycling and disposal of lithium batteries is difficult – although a lot simpler than recycling carbon from fossil fuels.
When it comes to efficiency, sodium batteries maintain their cost for for much longer than lithium batteries.
However as with all know-how, sodium-ion batteries current challenges. Sodium ions are greater and heavier than lithium ions. This implies the batteries are much less energy-dense than their lithium counterparts, and so require more room and materials to retailer the identical quantity of cost.
That is bettering, nevertheless. In response to one evaluation, the power density of sodium-based batteries in 2022 was equal to that of lower-end lithium-ion batteries a decade earlier.
And ongoing analysis and improvement means their energy-density continues to extend.
Attending to market
As with all promising applied sciences, a key query for sodium-ion batteries is once they would possibly develop into broadly commercialised.
To reply that, we could look to current evaluation primarily based on a way developed by the Massachusetts Institute of Expertise. It suggests sodium-ion batteries have gotten more and more aggressive on value – and so could enter the worldwide market as early as 2027.
The evaluation advised sodium-ion batteries would quickly match the price of utilizing gas-fired energy as a firming power supply.
Equally, an evaluation by the US power division in September final yr discovered sodium-ion batteries are “anticipated to undertake a big market share by 2030”.
It mentioned the know-how might develop into a aggressive alternative for lead-acid or lithium-iron phosphate batteries in each small-scale automobile electrification and “behind-the-meter” functions resembling backing up residence photo voltaic panel methods.
The evaluation discovered present and deliberate manufacturing of sodium-ion batteries was concentrated in China and Europe, and several other massive battery producers have been “projecting large-scale manufacturing services within the close to future”.
They embrace Chinese language electrical motorized vehicle firm BYD, which has reportedly began establishing a sodium-ion battery facility in Xuzhou.
In Australia, United Kingdom-based battery firm Faradion put in small stationary modules in Victoria’s Yarra Valley in 2022.
Retaining our choices open
A current plan by the Australian Power Market Operator (AEMO) suggests coal-fired energy can be phased out by 2035. However the plan suggests a big quantity of gasoline will stay within the grid.
The AEMO evaluation didn’t take a look at the potential for long-duration power storage to compete with gasoline. Nonetheless, the event of applied sciences resembling sodium-ion batteries suggests we must always query AEMO’s assumed want for gasoline in future.
Disruptive improvements develop rapidly and exponentially. We want solely look to the annual progress charges for present clear power applied sciences resembling photo voltaic (29%), wind (14%), electrical automobiles (54%) and battery storage (52%).
The Local weather Change Authority is at the moment assessing Australia’s potential know-how transition and emission pathways as we head in direction of net-zero emissions by 2050. Throughout the evaluation’s scope is to look at which applied sciences could also be deployed in every sector to help emissions reductions.
The potential of sodium-ion batteries suggests insurance policies put ahead by the authority shouldn’t lock in polluting choices for the electrical energy sector, resembling gas-fired energy. Cleaner options are prone to be industrial in a couple of years – and the soundness of our local weather is determined by planning for them.
 storage. At present, lithium-ion batteries are the primary storage technology but are best for short-term storage. Sodium-ion batteries are now almost ready to fill the long-term storage gap.){kind=link}