Sands of time, bring me change; a grainy solution to our demand for power?
As our need for power grows, businesses are forced to think of increasingly creative ways to meet demand AND reduce their carbon footprint. Could sand be the answer to our problems?
In the seemingly quiet town of KanKaanpӓӓ, Finland, a grey silo sits unassumingly attached to the Vatajakoski Polar Night Energy plant¹. In recent weeks, however, it has gained a lot of attention within the scientific community for being the world’s first, fully operational sand-powered battery. Sand? A source of power? Well, potentially. And perhaps not the sand, so much as its potential to store energy.
The concept behind the sand battery is simplicity at its finest but it could be the green solution to year-round energy demand. Low-grade sand (100 tonnes of it to be precise), the same grade of material that is widely used by builders, has been piled into a silo, capable of being charged up with heat energy from renewable sources and then slowly releasing it as means of warming houses throughout the winter². How? Solar panels and/or wind turbines generate green electricity and whilst some of that is used to directly power homes, the rest is pumped into the silo and stored within the sand as heat energy (reaching up to 500°c). It can then be progressively released over a period of 3 or more months, with the stored heat energy being converted into electricity to help power homes connected to the service³.
This isn’t, however, the first time that sand has been considered as an alternative means of power. Researchers at the University of California created a coin-sized silica-based battery in 2019 which was actually shown to last for up to three times longer than the conventional battery at the time⁴. Since then, engineers have been looking for a way to upscale and the team at Polar Night Energy are doing just that, pioneering the way for others in the future. Should the trial be successful, change like this really does seem to be the logical move when you consider that the current (and mainstream) competitor to sand-based battery power is lithium-based which, sadly, has quite the carbon footprint associated with its production.
Silica sand is abundant, stable and inexpensive to source, with a low ecological impact throughout its lifecycle³. Many factors go into making sand the greener choice over lithium which, although highly effective at storing energy, is mined in a process that demands considerable machine power, water and heat⁵. The carbon emission associated with such endeavours is high and should our current demands for power continue as they are now, the production of lithium-based batteries will see continued environmental degradation worldwide. The implementation of sand-based power on the other hand may just be the solution we are looking for. Could you imagine if the technology pioneered here could be applied in other aspects of life? What about the power stations that support global data centres or in less-developed countries across the world, helping to support a better quality of life. How would you like to see sand-based silo batteries used in the future? Do you think that it will prove viable?
References
[1]: Polar Night Energy (2022) Energy revolution is here. Available at: https://polarnightenergy.fi /about Accessed: 09/07/2022.
[2]: McGrath, M. (2022) Climate change: ‘Sand battery’ could solve green energy’s big problem. Available at: https://www.bbc.co.uk/news/science-environment-61996520 Accessed: 09/07/2022.
[3]: Hanley, S. (2022) Sand Battery Trials Begin In Finland. Available at: https://cleantechnica .com/2022/07/05/sand-battery-trials-begin-in-finland/ Accessed: 09/07/2022.
[4]: Puiu, T. (2019) Sand-based batteries last three times longer than conventional ones. Available at: https://www.zmescience.com/research/sand-based-battery-lithium-ion-5434/ Accessed: 09/07/2022.
[5]: Nature (2021) Lithium-ion batteries need to be greener and more ethical. Available at: https://www.nature.com/articles/d41586-021-01735-z Accessed: 09/07/2022.
