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  • As of 2020, the world's biggest lithium-ion battery

  • is hooked up to the Southern California power grid

  • and can provide 250 million watts of power,

  • or enough to power about 250,000 homes.

  • But it's actually not the biggest battery in the world:

  • these lakes are.

  • Waithow can a pair of lakes be a battery?

  • To answer that question, it helps to define a battery:

  • it's simply something that stores energy and releases it on demand.

  • The lithium-ion batteries that power our phones, laptops, and cars

  • are just one type.

  • They store energy in lithium ions.

  • To release the energy, the ions are separated from their electrons,

  • then rejoined at the other end of the battery

  • as a new molecule with lower energy.

  • How do the two lakes store and release energy?

  • First, one is 300 meters higher than the other.

  • Electricity powers pumps that move billions of liters of water

  • from the lower lake to the higher one.

  • This stores the energy by giving the water extra gravitational potential energy.

  • Then, when there's high demand for electricity,

  • valves open, releasing the stored energy by letting water flow downhill

  • to power 6 giant turbines that can generate 3 billion watts of power

  • for 10 hours.

  • We're going to need more and more giant batteries.

  • That's because right now, generating enough electricity to power the world

  • produces an unsustainable amount of greenhouse gas:

  • 14 billion tons per year.

  • We'll need to get that number down to net-zero.

  • But many clean energy sources can't produce electricity 24/7.

  • So to make the switch, we need a way to store the electricity until it's needed.

  • That means we need grid-scale batteries:

  • batteries big enough to power multiple cities.

  • Unfortunately, neither of the giant batteries we've talked about so far

  • can solve this problem.

  • The two lakes setup requires specific geography, takes up a lot of land,

  • and has high upfront costs to build.

  • The giant lithium-ion battery in California, meanwhile,

  • can power about 250,000 homes, yes, but only for an hour.

  • Lithium-ion batteries are great for things that don't use a lot of power.

  • But to store a lot of energy, they have to be huge and heavy.

  • That's why electric planes aren't a thing:

  • the best electric plane can only carry two people

  • for about 1,000 kilometers on one charge,

  • or its batteries would be too heavy to fly.

  • A typical commercial jet can carry 300 people over 14,000 km before refueling.

  • Lithium-ion batteries also require certain heavy metals to make.

  • These resources are limited, and mining them often causes environmental damage.

  • Inventors all over the world are rising to the challenge

  • of making batteries that can meet our needs

  • many of them even weirder than the two lakes.

  • One company is building a skyscraper battery.

  • When the sun is shining, a crane powered by solar energy

  • piles blocks on top of each other in a tower.

  • At night, the cranes let gravity pull the blocks down

  • and use the resulting power to spin generators.

  • Though there have been some early setbacks,

  • another promising approach involves heating up salts until they melt.

  • The molten salt can be stored until there's a high demand for electricity,

  • then used to boil water.

  • The steam can power turbines that generate electricity.

  • Another idea: bio-batteries made from paper, powered by bacteria,

  • and activated by spit.

  • Bacteria release energy in the form of electrons when they metabolize glucose,

  • and at least one species of bacteria can transfer those electrons

  • outside its cells, completing a circuit.

  • While these batteries won't power a city, or even a house,

  • they don't have the waste and cost concerns of traditional batteries.

  • From vast mountain lakes to microscopic bacteria,

  • from seawater batteries that bypass the need for heavy metals

  • to nuclear batteries that power deep space missions,

  • we're constantly rethinking what a battery can be.

  • The next unlikely battery could be hiding in plain sight

  • just waiting to be discovered and help us achieve a sustainable future.

As of 2020, the world's biggest lithium-ion battery

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B2 TED-Ed battery power energy lithium lithium ion

The world's biggest battery looks nothing like a battery

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    林宜悉 posted on 2021/02/22
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