Sand is so plentiful everywhere we go that we scarcely notice it under our feet. The composition of this granular mineral varies depending on the local geology. Although it is most likely to be silica in the form of quartz in inland continental settings. Storing energy in sand could help supplement batteries, and play an important role in renewable electricity that could help cool global warming.
The Science Behind Energy in Sand
Sand gets hot under our feet because it has a low ‘specific heat’ and absorbs warmth easily. It can also store large amounts of this energy, because it is so dense. Soldiers knew all about this form of energy storage a long time ago. They poured hot sand down on their enemies, from battlements high up in their forts and castles.
The shift to renewable energy has brought a fresh requirement for bulk energy storage. We can store electrical energy – because that’s what electricity is – in water in a kettle although this liquid soon cools, because its specific heat is relatively high. Sand is easy to access and it holds its heat well.
Making This Exciting Possibility Real
Special heaters use electricity from wind and solar to heat silica sand during off-peak periods. When this sand reaches the target temperature, it enters insulated silos for later use. This hot material can then retain 95% of its heat for at least 5 days according to Clean Technica.
What’s particularly great about this type of sand battery, is it does not require rare minerals with unsustainable supply chains. Everything we need except for the silo is literally under our feet, and everywhere we go in inland continental settings.
Uses For Stored Energy in Sand
Energy stored in sand on a micro level can be used to heat buildings in winter, instead of using natural gas that adds carbon to the atmosphere. It could also be used for washing up and bathing, but there is more to it than just that.
The heat in sand could also be used to power conventional steam turbines, while we still need them. Implementing these two options could considerably reduce the amount of carbon entering the atmosphere, and with it, global warming too.
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One Hundred Megawatt-Hour Sand Battery
