DataBank’s UPSs, power distribution units (PDUs), generators, and other power equipment must operate at their highest level. If there’s a power outage, it could mean devastating circumstances for the company’s colo customers, resulting in a loss of trust. “Weather-related power transients are not uncommon, and we require all of our power infrastructure systems to be at the ready at all times,” said Danny Allen, DataBank’s vice president of engineering.
The UPS batteries in DataBank’s 100,000-square-foot facility in Plano, Texas, as well as at its Tier III data centers in Kansas City, Pittsburgh, and Atlanta, were coming to the end of their useful life. Allen wanted to incorporate a more reliable, economical, and sustainable alternative to the lead-acid batteries they were using with their UPS systems.
While valve-regulated lead-acid (VRLA) batteries have long been the mainstay for power backup with UPSs, they have their challenges — they’re unpredictable and require frequent replacements, and they also have precise cooling requirements and a large footprint, to name a few.
A Different Approach
Today’s technology enables flywheels to charge and discharge at high rates for countless cycles without degradation over the course of their 20-year life spans.
Having previous experience with the reliability, cost, and green aspects of flywheels at DataBank’s other data center facilities, Allen was confident in his choice to deploy 36 of Vycon’s VDC XXE 300kW flywheel systems along with 12 VDC 450kW XXT models to start up in January 2020.
All of the flywheels are paired with Mitsubishi 9900B-750kVA three-phase, online, double-conversion UPS systems.
“The dependable reliability and very low maintenance costs of the Vycon flywheels, along with their green advantages, make it an easy decision to replace lead-acid batteries,” Allen said.
“When the flywheels are spinning, it’s not a guessing game if they’re going to work,” said John Jeter, director of sales for Vycon. “If there’s anything wrong, they won’t run. With batteries, one never knows if they’ll work until they are under load.”
The VDC Advantage
Certified by most major vendors of three-phase UPSs, the systems interface with the DC bus of the UPS just like a bank of batteries would, receiving charging current from the UPS and providing DC current to the UPS inverter during discharge. Upon loss of utility power to the UPS, up to 750 kW of regulated DC power per VDC unit is instantly delivered to the UPS. This provides the backup power needed to startup and transition to DataBank’s 2.5-MW generators during a prolonged utility outage. Typical VDC configurations can provide from 15 seconds to more than two minutes of backup power (depending upon load levels and number of flywheel modules). Since the average backup generator requires less than 10 seconds to come online, the flywheel provides plenty of time for a smooth power transfer to the on-site generators.
Low Cost of Ownership
The VDC flywheels are capable of hundreds of full charge and discharge cycles over the life of the system with no degradation in voltage, power, or storage. Flywheel technology is also considered the only green technology of the energy storage options.
Unlike other flywheel technologies, the VDC flywheel uses a contact-free magnetic levitation system, eliminating the need for mechanical bearings. In addition, using a flywheel versus a five-minute VRLA battery bank can provide $100,000 to $200,000 in cost savings per flywheel deployed over its 20-year lifetime.
Vycon’s flywheel systems are installed in thousands of mission critical facilities around the world. For DataBank, the VDC units have already been put to the test.
“During a recent storm, the Vycon flywheels performed as expected,” Allen said. “While system reliability is our priority, by eliminating the batteries, we’re saving at least $10,000 per year in battery maintenance and replacement.”
Flywheel energy storage has become a strategic solution for mission-critical applications that require reliable, predictable backup power while reducing carbon footprint. At DataBank, the flywheel energy storage solutions help maintain its PUE rating of 1.3.