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This Sand Battery Is An Audacious Attempt To Store Green Power
Engineers in Finland may have discovered a cheap and effective way to get the most out of their country's wind and solar power systems. Polar Night Energy claims to have constructed “the first commercial sand-based energy storage” in the world, and its facility is currently operational, signaling a potentially big step toward a carbon-neutral future.
Since energy generated from sources like the wind and sun is not constant and reliable unlike, say, the burning of coal, harnessing renewable energy requires an effective storage method for continuous power. This is especially important in Finland, as ideal weather conditions can be challenging — for instance, the country faces a few months of total darkness in the winter.
The sand battery rests on a simple idea: It uses a large silo of cheap, low-grade sand to store thermal energy created from renewable sources. This thermal energy can be made when there is an excess of one type of power — like solar in the middle of summer — and then be released as needed and used to heat water which is then used to heat homes and public buildings.
The engineers claim that the sand can hold on to the heat for “several months.” Cost- effectiveness is also central to the battery's design, as the low-grade builder's sand used is incredibly cheap when compared to metals like lithium. However, there is a downside: the battery’s efficiency drops drastically when pulling the stored energy out as electricity.