Gravity could offer new method of energy storage
According to the First Law of Thermodynamics, energy can neither be created nor destroyed – it can only be conserved. So how is Gravitricty creating energy from empty mine shafts?
In essence, energy doesn’t just pop in and out of thin air. But we can make it pop up out of the ground. The UK’s industrious past saw as many as 150,000 mine shafts created to mine coal, with many more left unrecorded or missing entirely.
While the concept of mining is often associated with ‘dirty’ sources of power such as coal, oil and gas, new technology promises a fresh take on mines and an altogether cleaner source of energy.
The gravity of the situation
UK-based firm Gravitricity believes it has pioneered a new form of energy storage, which involves suspending weights above deep mine shafts. The weights, which weigh 25 tonnes, can be raised and lowered, generating power as they drop. They would then use excess power from wind turbines to wind back up again in preparation for the another energy release upon their next drop.
Legend has it that Isaac Newton formulated the theory of gravitation after watching an apple falling from a tree in the 17th century. In 1687, Newton published his theory, claiming that any two particles in the Universe were attracted to one another by a force proportional to the product of the two masses, and inversely proportional to the square of the distance between them.
In plain language, an apple falls to Earth because the mass of the Earth is far greater than the apple’s, thus pulling the apple towards it. On a larger scale, the Sun’s immense mass keeps the entire solar system locked into specific orbital planes thanks to its gravitational pull.
An attractive form of energy storage
Gravity is a powerful force of nature but it is invisible to our eyes. It shapes the Universe in which we live, and Gravitricity found it so compelling as a method of energy storage that it built a 250kW test rig at the Port of Leith, Scotland. This rig allows Gravitricity to offer a small-scale test version of what could become a far larger method of energy storage.
If successful, this new method could create rigs with a 50-year life span, capable of going from zero to full power in less than one second. The technology harnesses the best aspects of lithium-ion batteries and pumped storage, while operating at a far more affordable price level.
To progress further, Gravitricity is launching a crowdfunding campaign, having previously raised £1.5 million between 2019-20 for the Port of Leith test rig. The new fundraiser could be a real test to determine the true attractiveness of weight-based energy storage.
Sometimes, the best way to go up in the world is to dig down into the depths of the earth.