Lithium-Ion: Flywheel's Replacement

The Advantages of Lithium-Ion for High Temperature / Short Runtime Applications




by Dann McKeraghan, National Account Manager

How much consideration have you given lately to the DC energy storage options available for your Uninterruptible Power Supply (UPS)?


The good news is that you have never had as many options as you do today. DC energy storage has advanced from high maintenance wet cell batteries to options that include sealed Valve Regulated Lead Acid (VRLA), Pure Lead, flywheels and various lithium-ion chemistries – and there are many more to come.


Traditionally, when users were looking for a DC energy solution that could withstand high temperatures, provide short runtimes, and have less maintenance, they turned to flywheels. Flywheels store their energy in the form of a rotating mass paired with power electronics to provide DC energy for short (15 seconds) ride through applications when paired with a UPS.


Lithium-ion brings many benefits and advantages over flywheel energy storage, including lower CAPX and/or OPEX, increased performance, smaller footprint, reduced maintenance / downtime, longer operation life, high operational temperate range and testing to UL9540A.


The successful introduction and adoption of lithium ion brought with it an option or alternative to flywheel storage that takes advantages of the listed improvements and provides customers with more of why they purchased DC energy storage….Back up time!


As prices and availability of lithium ion batteries have significantly improved over time, the move to lithium ion where flywheels may have been previously deployed continues to grow.


Take, for example, a 300kW UPS with lithium ion batteries compared to the same sized system with flywheels. The CAPEX for both is roughly the same, but the runtime for the lithium ion solution is 10 to 20 times greater, thus making it a more attractive alternative.



Results may vary based on final configuration


Lithium-ion batteries require very little in the way of maintenance. Once a year, a noninvasive inspection is performed thereby eliminating downtime experienced for flywheel maintenance items, such as bearing changes and vacuum pump maintenance /replacement.


The lithium-ion batteries available today can safely operate up to 95ºF (35ºC), allowing for reduced cooling demand and making them suitable for applications that previously had been filled by flywheels.


Operational life for some lithium-ion batteries at elevated temperatures can be as much as 20 years. The additional runtime also provides protection from nuisance generator starts and allows for more comfortable UPS/Generation walk in times.


In summary, utilizing lithium-ion batteries for static UPS applications compared to flywheel energy storage offers lower cost of ownership, less maintenance / downtime, and most importantly, more back up runtime to allow a successful transfer to your generator. 


Edited by Nicole KristofDigital Marketing Specialist & Michael Ruhe, Product Manager, Engineered Solutions

Stay up-to-date on industry trends & insights

Follow us on social media