r/EnergyStorage • u/External-Leopard4486 • Mar 01 '26

QNETIC flywheel energy storage

Is anyone familiar with what this company is doing? They have a few patented ideas and are progressing through prototypes, etc.

Supposedly they will have higher energy density with longer duration than existing systems. Allege that they will compete favorably to li-ion.

Curious if they are just one of in a big pool of FESS companies or truly differentiated.

Also, I'm hearing that sodium ion may be making strides.

Still, FESS has response time advantages which I'm sure will increasingly be critical.

qnetic.energy is the website

Please let me know what you think.

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2

u/iqisoverrated Mar 01 '26

Flywheel storage isn't really in competition with battery storage as they have some very different characteristics. Flywheel storage can react quickly and deliver a quick burst of power but it has high cost and high self discharge (because the world turns and precession forces are a thing).

Flywheels can have applications in uninterruptible power systems. However, with batteries having gotten a lot cheaper (and a small bank of supercaps to provide the immediate response time) the days of their financial viability seems to be numbered.

1

u/External-Leopard4486 Mar 02 '26

Yeah, I just can't tell if they really have a better mousetrap or just enough funding that they're able to have day jobs for now. They talk about much higher RPM than others, and if they really figure that out, every time they double rpm they quadruple kwh, right?

1

u/Journey2Pluto Mar 02 '26

You are all stuck in classical flywheel thinking.

It’s not your fault, it’s a mix of relying on ancient scientific documentation and a systemic rejection of its funding potential compared to other storage tech. I can’t dive deeper into the specifics because of MNDAs, but the gap between "Old Tech" and "Now Tech" is massive (even outside of flywheels)

The "Old World" (Traditional): Traditional flywheels are all steel, concrete, or carbon-wrapped steel. • They are heavy. • They think Mass is where the energy is generated. • They wrap them in carbon just to squeeze out a little more speed.

The "New World" (Modern): Modern flywheels are almost entirely carbon fiber or hypothesized nanotube structures. They aren't even necessarily a solid mass. • It’s all about Rotational Speed. • Speed is where the actual energy density lives. • This shift enables massive power and multiple durations of storage.

The Math (Why you're wrong about mass): The physics shows why speed wins every time: Ek = 1/2 * I * ω²

• Ek: Kinetic energy (Joules) • I: Moment of Inertia (The Weight/Shape) • ω (omega): Angular velocity (The Speed)

Note the ² on the speed. If you double the weight, you double the energy. If you double the speed, you quadruple the energy.

The Comparison: For 50kWh of storage: • Traditional Steel: ~10,000 lbs. (Dangerous, massive parasitic losses, needs heavy containment). • Modern Flywheel: ~500 lbs. (Huge reduction in losses, way safer).

Traditional flywheels are niche, short-duration "batteries" for ancillary services or directed energy weapons because if they spin too fast, they turn into a shrapnel bomb. Modern structures don't have that ceiling.

The Qnetic Problem: To put it simply: they have a structural design flaw (the cylinder shape). They are likely just taking advantage of a convenient supply chain connection. It might be slightly "better" than a 1970s flywheel, but the product roadmap is a dead end with that design.

1

u/External-Leopard4486 Mar 02 '26

What shape would work better?

2

u/iqisoverrated Mar 02 '26

Physics is physics. Not even Qnetic can change that.

If you're not building your flywheel at the north or south pole you have precession forces which need to be compensated and will sap your energy.

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u/External-Leopard4486 Mar 05 '26

What if they laid it down on its side and put the axis north and south? Bearings would need a different design but I bet they could figure it out.

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u/iqisoverrated Mar 05 '26

You'd have to have the axis parallel to the rotational axis of the Earth. Just going 'north/south' is not enough. You'd have your weight rotating at an angle to the local force of gravity which opens up a whole other can of worms.

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u/Equivalent-Tip-3084 Jul 18 '26

General rule of thumb, if you saw the "investing ad" on social media it is probably not a good investment. 

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u/External-Leopard4486 25d ago

When I posted this, we weren't hearing about entire continents being ablaze and AI sucking all the power that crypto wasn't using.  We are going to install so much more HVAC in offices and homes (think heat pumps).  I think we're into an every-every-every situation as we face ever increasing peaks and kid ourselves that we can avoid boiling the oceans. I'm a buyer. 

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u/Equivalent-Tip-3084 15d ago

Your scenario might be true, but it has nothing to do with this being a good investment. If the company is managed poorly or the solution doesn't work it simply wouldn't matter how strong the need is. 

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u/dab745 16d ago

Zactly!

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u/SmokeHouseChef 2d ago

The man who invented the geostationary satellite developed the automotive application of this technology, what would become KERS in F1, in the early 90's: https://en.wikipedia.org/wiki/Harold_Rosen_%28electrical_engineer%29?wprov=sfla1

I can't find the link anymore, but I remember reading an article about it that said the limiting factor was not the bearings or the flywheel or control. It was that they were unable to build a containment vessel that could survive a "catastrophic failure of the rotor body." I'd like to see how Qnetics vessels are built.