Pentadyne GTX: Backup Power from a Flywheel

Flywheels are spinning disks that store kinetic energy for use as a short-duration power supply. These systems have been around since the 1960s, but older units used heavy steel discs weighing as much as 6,000 pounds (2,700 kg) that spun at relatively low speeds of less than 4,000 rpm. Newer steel flywheels are lighter and spin faster but still require special installation and regular maintenance, consume a lot of power, and generate a lot of heat. Pentadyne flywheel systems, however, store power using a lightweight hub and carbon-fiber flywheel weighing just 58 pounds (26 kg) and spinning at up to 52,000 rpm.

“Kinetic energy is equal to mass times velocity squared,” said Jeff Colton, senior vice-president of sales and marketing at Pentadyne, “so doubling the rotational speed quadruples energy storage.” Using high-speed rotation, the GTX can supply 200 kilowatts of continuous power for over 12 seconds and recharges in less than 15 seconds; the units can also be linked in parallel for larger kilowatt demands or run time. This may not seem like a useful amount of coverage, but 98% of all power anomalies last less than ten seconds, according to the Electric Power Research Institute.