The article doesn't explain the battery, making it a bullshit site if you ask me, here is what they are talking about:

https://en.wikipedia.org/wiki/Vanadium_redox_battery

'The vanadium redox battery (VRB), also known as the vanadium flow battery (VFB) or vanadium redox flow battery (VRFB), is a type of rechargeable flow battery which employs vanadium ions as charge carriers.[5] The battery uses vanadium's ability to exist in a solution in four different oxidation states to make a battery with a single electroactive element instead of two.[6]

For several reasons, including their relative bulkiness, vanadium batteries are typically used for grid energy storage, i.e., attached to power plants/electrical grids.[7] '

The headline looks wrong, but it actually isn't.

The article specifies:

• Total capacity: 2.1GWh
• Peak output: 1.2GW
• Ramp up time: a few milliseconds

That's what the "within milliseconds" in the title refers to.

Every power generator has a ramp up time. Think the time it takes to start the engine in a diesel generator, until it spins up and is able to output peak power.

Nuclear reactors can hare ramp-up times of hours, in some conditions even days.

This thing here can go from zero to peak output within almost no time, which makes it perfect to balance the sometimes erratic and unpredictable generation fluctuations of renewable energy production.

For comparison, coal or gas power generators usually have large flywheels that, once spinning, react almost instantly to power fluctuations in the network by converting their motion to electricity or the other way round. If these coal or gas generators aren't running, they can't be used to balance the fluctuations in the network, so battery solutions like the one in OP are required to actively manage the network stability.

Yeah, no, it's not going to output 1.2 gW in milliseconds.

We don't know soccer fields around these parts...

I wanted to research it myself since I didn't know how Redbox flow batteries operate. It is two giant tanks of liquid energy. When there's extra electricity from wind or solar, pumps move special vanadium-based liquids through a stack of cells, storing that energy as a chemical change. When electricity is needed later, the process runs in reverse and the liquids generate power for the grid. Unlike lithium batteries, the energy is stored in the liquid tanks, so making the battery bigger is mostly a matter of building larger tanks. The Swiss project will store about 2.1 GWh of energy—enough to help balance renewable power on a massive scale—and was chosen partly because redox-flow batteries are non-flammable, long-lasting, and can be cycled tens of thousands of times with little degradation

How big is a soccer field?

Asked for comments, they kept saying "Rest assured there is no death ray plans"

(/j)

Wow, that's almost 10% of a single datacenter

able to output 1.2 GW within milliseconds

By exploding?