Gravity could solve one major draw of clean energy
In Switzerland valley, an unusually unarmed crane lifts two 35-tonne concrete blocks high into the air. The blocks move slowly up the blue steel frame of the mast, where they hang from either side of a 66-meter-wide horizontal arm. A total of three arms, each holding the cables, winches, and catch hooks needed to lift another pair of blocks into the air, give the machine the look of a giant insect. building and stacking bricks with steel nets. Although the tower is 75 meters high, it is easily damaged by the wooded edges of the Lepontine Alp of southern Switzerland, which rises from the valley floor in all directions.
Thirty meters. Thirty-five. Forty. The concrete blocks are slowly built up by motors powered by a Swiss power grid. For a few seconds they hang in the warm September air, then the steel cables holding the blocks start unwittingly and begin the slow descent to join the few dozen similar blocks at the base of the tower. This is the time when this intricate dance of steel and concrete was designed. As each block descends, the motors that lift the blocks begin to spin in the opposite direction, generating electricity that passes through the thick cables that run down the side of the mast and into the grid. power. In the 30 seconds when the blocks subside, each one generates about one megawatt of electricity: enough to power about 1,000 homes.
This tower is a prototype of Swiss-based Energy Vault, one of several startups looking for new ways to use gravity to generate electricity. A full-size version of the tower can hold 7,000 bricks and provide enough electricity to power thousands of homes for eight hours. Storing energy in this way could solve the biggest problem facing the transition to renewable electricity: finding a carbon - free way to keep the lights on when they are not. the wind blows and the sun does not shine. "Our biggest hurdle is getting low-cost storage," said Robert Piconi, CEO and accountant for Energy Vault.
Without a way to disarm the world's electricity supply, we will never hit greenhouse gas emissions by 2050. Electricity and heat production will account for up to a quarter of global emissions and, as almost every action you can think of requires electricity, cleaning up power grids has a huge impact. If our electricity goes greener, so do our homes, businesses, and transportation systems. This will become even more urgent as more parts of our lives are electrified - especially heating and transport, which will be difficult to disarm in any other way. All of this electrification is expected to double electricity production by 2050 according to the International Atomic Energy Agency. But without an easy way to store a lot of energy and then release it when we need it, we may never lose our trust in dirty, polluting, fossil fuel power stations.
This is where gravity energy storage comes into play. Supporters of the technology argue that gravity provides a neat solution to the storage problem. Instead of relying on lithium-ion batteries, which deplete over time and require rare earth metals that need to be dug out of the ground, Piconi and colleagues say that gravity systems could provide a cheap, plentiful and permanent source of energy that we are currently overlooking. But to prove it, they need to build an entirely new way to store electricity, and then convince an industry that is already going into lithium-ion batteries that there are heavy weights in the future falling from great heights.