Waiting for patents to file before public disclosure of the tech, but I can give you a basic overview. We use mass instead of speed to store energy. This is slightly less efficient but way less expensive; speed requires magnetic bearings and operating in a vacuum and many other expensive design constraints. Other flywheels operate in the 7500 - 100k RPM range, and we spin at 2000.
Bearing and windage losses scale down drastically with lower speeds, so only slightly worse than other flywheel systems. They are best for daily cycles or multiple-daily cycles. Things like load shifting, peak shaving, frequency regulation, etc. They are not well suited for storage beyond a few days.
