Stacking Concrete Blocks Is a Surprisingly Efficient Way to Store Energy
August 19th, 2018I like to follow these relatively low-tech methods of energy storage, even though they don’t seem to catch on. It’s interesting to see a modern take on old ideas.
The Energy Vault (below) is a similar concept to the Ares, which stores energy by moving a mass up a hill on rails. The Energy Vault, however, doesn’t require a hill because it uses a crane to stack concrete cylinders.
Despite the issues with lithium, the fact that those systems can deliver large amounts of power very quickly makes them highly desirable:
Tesla’s battery last week kicked in just 0.14 seconds after one of Australia’s biggest plants, the Loy Yang facility in the neighbouring state of Victoria, suffered a sudden, unexplained drop in output, according to the International Business Times. And the week before that, another failure at Loy Yang prompted the Hornsdale battery to respond in as little as four seconds — or less, according to some estimates — beating other plants to the punch. State officials have called the response time “a record,” according to local media.
Maybe a mix of lithium and low-tech systems would be good. The lithium batteries could supply the instant surge capacity while some slower responding systems spin up.
Via: Quartz:
A startup called Energy Vault thinks it has a viable alternative to pumped-hydro: Instead of using water and dams, the startup uses concrete blocks and cranes.
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The science underlying Energy Vault’s technology is simple. When you lift something against gravity, you store energy in it. When you later let it fall, you can retrieve that energy. Because concrete is a lot denser than water, lifting a block of concrete requires—and can, therefore, store—a lot more energy than an equal-sized tank of water.
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The round-trip efficiency of the system, which is the amount of energy recovered for every unit of energy used to lift the blocks, is about 85%—comparable to lithium-ion batteries which offer up to 90%.
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Meanwhile, whether or not Energy Vault succeeds, it does make a strong case for the argument that, while everyone else is out looking for high-tech, futuristic battery innovation, there may be real value in thinking about how to apply low-tech solutions to 21st-century problems.
