This Small Business Innovation Research (SBIR) Phase I project will explore Flywheel Energy Storage (FES) systems as an alternative to batteries for electrical energy storage in remote, cold environments. Use of renewable energy sources in wind and solar power is complicated by a lack of suitable storage. Batteries are typically heavy and expensive to transport; have limited life, require warmth for effective operation; and pose disposal problems at the end of their life. FES may offer higher energy densities, unlimited life, relative insensitivity to low temperatures, and absence of toxic compounds. Due to the high rotational speeds, flywheels require magnetic bearing support, but active magnetic bearings require power supplies and control electronics that reduce storage efficiency and present failure points and maintenance needs. Passive magnetic bearings are a better choice for stationary FES systems but have been difficult to manufacture and suffer from low damping. Phase I will develop a passive bearing system that is easier, and less expensive to manufacture. The flywheel and its damping systems would allow these new bearings to be applied to stationary FES systems. The commercial applications fall into three classes: alternative energy storage, utility load leveling, and uninterruptible power applications. Solar electric systems are thought to be a growth market in which FES has advantages over conventional batteries. Utility load leveling applications would result in cost savings in maintenance and peaking power facility costs. Uninterruptible power supplies may also be a growth market.
