Energy Vault plans to use excess solar and wind energy to construct a tower of huge concrete blocks. When electricity is needed, the blocks are lowered and the resultant kinetic energy creates electricity. One tower can create energy for hours, and it can store it indefinitely, which is a huge plus. Response times are very fast too.
This is similar to pumped hydro, where water is pumped uphill to a reservoir and released to power turbines when electricity is needed. SoftBank impressed enough with the idea to put $110 million into it. They like the plan because it’s simple and proven, “fifth-grade physics.”
Energy Vault’s consists of an almost 400-foot tall, six-armed crane with custom-built concrete blocks weighing almost 35 metric tons each. As solar or wind energy is siphoned into an Energy Vault tower, an A.I. directs the concrete blocks to rise up.
Then, according to the company’s website, the blocks are “returned to the ground and the kinetic energy generated from the falling brick is turned back into electricity.”
That kinetic energy then turns a motor, which passes through an inverter, sending the energy back into the grid. Energy Vault claims the process had a “round-trip efficiency between 80 to 90 [percent].”“We at the Vision Fund want to come in when a technology is proven and it’s ready to scale. That’s what’s so exciting about this technology. It’s not a science problem. It’s fifth-grade physics.”