Does it work?

Question 1

How does a flywheel battery work?

Accepted Answer

Electricity spins a magnetically levitated rotor inside a sealed vacuum, turning electrical energy into the energy of motion. When the grid needs power, the spinning rotor drives a generator and that motion becomes electricity again. There is no electrochemical cell anywhere in the system. The commercial product is the Q500, developed under the codename Pulsar.

Question 2

How much energy and power does one unit hold?

Accepted Answer

The Q500 is being designed for 500 kWh of usable energy at 125 kW nominal power, with peaks up to about 300 kW. That is roughly four hours at rated power, and longer at partial power. These are design targets for the commercial product, not figures demonstrated in the field yet.

Question 3

Does the rotor sit on ball bearings, or only on magnets?

Accepted Answer

At operating speed it is held entirely by magnets, in all three dimensions, with an air gap all around. Nothing touches it, so there is no friction and no wear. Permanent magnets carry the weight without drawing power, and active magnetic bearings keep it centered. For fault protection there are two separate mechanical systems behind the magnets: an emergency safety bearing, and a touchdown backup bearing behind that.

Question 4

How fast does the rotor spin?

Accepted Answer

Its design speed is 11,000 rpm, about what a jet engine's fan turns and faster than a car engine. For a rotor this large, the number that matters is how fast the rim moves, and at full speed it travels at roughly twice the speed of sound. The strength of the carbon fiber sets that limit. The rotor is tested to a higher speed than it will ever run at, which is its safety margin, and the control system never lets it go past 11,100 rpm.

Question 5

Does it generate power, or only store it? Which power sources work with it?

Accepted Answer

It stores power, it does not generate it. It connects to the grid, so it works with any source: solar, wind, hydro, gas or nuclear. It stores electricity when there is surplus and releases it when the grid needs it. It also pairs well with generators that prefer to run steadily, such as nuclear plants and small modular reactors. Storage can shift their output to peak hours and absorb fast load changes, so the plant does not have to chase demand.

Question 6

What is it made of, and where do the materials come from?

Accepted Answer

The rotor is standard industrial-grade carbon fiber (T700 class) in epoxy, a widely produced material rather than an exotic one. For the US market, Qnetic intends to source both the carbon fiber and the resin in the United States. Those arrangements are being set up now, ahead of commercial production. The rotor levitates on neodymium (NdFeB) permanent magnets, which today come from China. Qnetic takes that concentration seriously. Alternatives such as samarium-cobalt and higher-grade NdFeB, along with other suppliers, are being evaluated. No non-rare-earth magnet yet matches the strength and heat stability the design needs, so this is an open supply-chain problem rather than a solved one.

Question 7

Flywheels aren&#8217;t new. Why haven&#8217;t they gone mainstream?

Accepted Answer

The physics is well proven, and flywheels already run on the grid today, but mostly for seconds to minutes of power. Qnetic's work is a flywheel that stores energy for hours at grid scale. That takes a light, very fast rotor, magnetic bearings controlled to fractions of a millimeter, and a vacuum. The difficulty is in that engineering, and the Vega and Pulsar prototypes are proving it one step at a time.

Question 8

Could it power ships, planes or vehicles?

Accepted Answer

In principle yes, and it has been tried, but a heavy spinning mass resists changes in direction, which makes vehicles a poor fit. Qnetic builds stationary storage for the grid.

Question 9

What is the round-trip efficiency?

Accepted Answer

The target is 85% round trip for a four-hour system, broadly on par with lithium-ion in similar applications. Complete round-trip efficiency, from AC in to AC out, has not been measured on Pulsar yet, so 85% is a target, not a result. Measured figures are targeted for the second quarter of 2027. Individual components have been measured. The motor-generator, for example, has shown over 97% efficiency, but the full system also includes power electronics, magnetic bearings, the vacuum system and other auxiliaries. Pulsar is the platform that measures those system-level losses. Qnetic does not expect to win on efficiency alone. The case is comparable efficiency plus heavy cycling with no cycle-driven capacity loss and a 30-year design life.

Question 10

How often can it charge and discharge?

Accepted Answer

As often as the grid needs. Cycling does not wear down a flywheel's storage capacity the way it wears down a chemical battery, so frequent partial cycles or several full cycles a day do not shrink what it can hold.

Question 11

How much power does it take to levitate, cool and run the system?

Accepted Answer

The active magnetic bearings and the cooling system are the main loads. On Vega, all auxiliaries together drew a few kilowatts. Pulsar's figure will be measured during testing, and it is part of the round-trip number above.

Question 12

How does it compare with lithium-ion on lifetime cost?

Accepted Answer

A lithium-ion system loses capacity as its cells fade, so owners add or replace cells every few years to keep it at nameplate. A flywheel's capacity does not fade with cycling, so there is no augmentation and no mid-life cell replacement. That is where the lifetime cost advantage comes from. The design goal is a capital cost comparable to lithium-ion at production scale. Qnetic is updating its cost model and levelized-cost white paper and will publish the new figures there. The business case does not depend on lithium-ion getting worse: the earlier modeling already assumed large lithium improvements.

Question 13

How long does it hold a charge? How long will it keep producing power?

Accepted Answer

The Q500 is being designed to deliver its rated power for about four hours, and longer at partial power. A flywheel slowly loses a little energy while it holds a charge, mostly to its bearings and cooling. Pulsar testing will measure that standing loss, which is why Qnetic sizes it for daily cycling rather than for storing energy for weeks.

Question 14

Isn&#8217;t a flywheel just a very heavy wheel?

Accepted Answer

Stored energy grows with the square of speed, so doubling the speed stores four times the energy. That is why Qnetic uses a lighter carbon-fiber rotor spun very fast, rather than a heavy steel wheel spun slowly. The full-size rotor is still large, but speed does most of the work.

Question 15

Why does it need a vacuum, and how is it maintained?

Accepted Answer

At high speed, air around the rotor would act like a tornado and waste energy as drag. A pump rack removes the air, including a turbomolecular pump that reaches a very low pressure. The vacuum pump is one of the serviced parts with a scheduled replacement.

Question 16

Does temperature affect it? Does it need air conditioning?

Accepted Answer

Because the rotor spins in a vacuum, it cannot be air-cooled. The bearings and motor-generator sit on a closed liquid-cooling loop instead, a bit like an air-conditioning unit. The design does not need the building-scale climate control that large battery installations use. The operating temperature range will be confirmed in testing.

Question 17

What voltage does it connect at? Is the inverter included?

Accepted Answer

Qnetic delivers the integrated machine: rotor, magnetic bearings, power electronics, controls and safety systems, not just the mechanical parts. The power electronics and control panels use established, UL-certified components. The Pulsar demo connects to the grid at 480 V three-phase, the US standard. Project-specific interface details are shared with technical buyers and investors on request.

Question 18

Have you considered graphene or other advanced composites?

Accepted Answer

Qnetic tracks graphene-enhanced composites as part of longer-term materials research. The current focus is qualifying the existing carbon-fiber and epoxy rotor. Next-generation materials can be evaluated once that is established.

Question 19

How much space does a project need?

Accepted Answer

As a planning estimate, a project fits roughly 300 to 400 MWh per hectare. That is comparable to typical lithium-ion projects, without the fire lanes and perimeter setbacks lithium needs. Actual sizing is worked out site by site.

Question 20

What if lithium-ion or new chemistries like lithium-air keep improving?

Accepted Answer

The business case does not depend on lithium-ion stalling. Qnetic competes on long life, heavy cycling, no cycle-related capacity loss and lifetime cost, and its cost modeling already assumed large lithium-ion improvements. Qnetic does not see emerging chemistries changing that.

Question 21

How does it compare with solid-state batteries?

Accepted Answer

Solid-state batteries are not yet in commercial use for utility storage, while flywheels already run on the grid. A like-for-like comparison would need a specific solid-state design to compare against.