Flywheel systems store energy kinetically rather than chemically. Instead of dozens of 100-pound containers of lead plates submerged in sulfuric acid, flywheels use the inertia of a spinning mass to store and regenerate power.

Key advantages of high-speed flywheels

Faster, stronger, lighter, smaller

First generation flywheels, still sold today, were introduced in the mid-‘90s. They use a massive steel disk rotating at a relatively slow speed.

Kinetic energy is roughly equal to mass times velocity squared. So doubling mass doubles energy storage, but doubling the rotational speed quadruples energy storage.

Thus it makes sense to use less mass to create a lighter, more compact footprint, but make the material stronger and safer (hence Pentadyne’s carbon-fiber-composite flywheel cylinder) and spin it faster to maximize energy density.

Patented, bearing-free operation

Heavy steel flywheels have mechanical bearings that must be replaced every 2-3 years at a cost of thousands of dollars and the better part of a day’s worth of downtime. Not so with the Pentadyne system. Its small spinning mass is completely magnetically levitated: no bearings. This eliminates a mechanical point of failure as well as the friction, heat generation/cooling needs, energy waste and maintenance/downtime issues related to bearings.

Patented, pump-free operation

Flywheels spin in a vacuum to minimize aerodynamic drag. Other systems use a constantly operating mechanical pump to maintain a rough vacuum. Instead, Pentadyne’s award-winning systems use a patented molecular vacuum sleeve on the flywheel shaft. The shaft speed combined with the sleeve’s helical grooves maintain the system’s high vacuum (<5 millitorr, or >99.9993% evacuated). This eliminates a mechanical point of failure, energy consumption and maintenance/downtime issues related to a continuously operating mechanical pump.

Synchronous reluctance motor-generator

Pentadyne uses a synchronous reluctance motor-generator design that’s more energy efficient than permanent magnet types used in conventional flywheel systems. Permanent magnets are sensitive to heat and become less capable of operating to full capacity over time. This is particularly an issue in a vacuum environment. Pentadyne’s synchronous reluctance motor-generator design is somewhat more costly, but has no demagnetization issues even in temperature and vacuum extremes. This ensures performance of your Pentadyne system will not degrade over time.

Exceptional energy efficiency & minimal heat generation

Flywheels have many advantages over lead-acid UPS batteries, but energy efficiency hasn’t been one of them, until now. Thanks to the key technology aspects noted above, the standby energy consumption of a Pentadyne flywheel is a mere 300 watts, the same as the “float charge” consumption of a battery bank with similar capacity. Our competitor’s flywheel system uses 2,500 watts! That energy waste alone will cost you $3,000 or more in higher electric bills per year per cabinet. Then there’s the heat generation your cooling system will need to offset. Battery sets generate lots of heat, and competing flywheels vent more than 8,500 Btu/hr. Ridding your facility of all that extra heat further impacts your utility bills and cooling systems. In contrast, the Pentadyne system generates less than 1,000 Btu/hr.