Like hospitals throughout the world, Virtua Health, a nonprofit southern New Jersey health care provider, depends on its huge battery bank to insure that generators will start up in the event of an outside power problems. The multi-hospital system has 7,100 clinical and administrative personnel and 1,800 physicians caring for thousands of patients. Keeping the power on is critical to their care. But using batteries, as a backup brings a whole list of issues that made alternatives look inviting.

“Batteries tend to swell,” says Nelson Vasquez, network technology specialist with Virtua Health. “The swollen batteries cost us $18,000 to replace. We require 80 batteries of them and they all needed to be shipped and installed within 24 hours.”

Chas Thawley, Virtua Health’s network services manager, says that with batteries there is always a certain amount of risk involved because there is a chance that they may not work. Plus, each time the batteries are tested—a monthly requirement—the batteries’ lives are shortened. “Hospitals are now required to do a monthly generator test with load by the Joint Commission on Accreditation of Health Organizations, (JCAHO). While this is a sound practice that Virtua endorses, it requires us to employ a generator and a battery. Every cycle on a battery lessons its lifespan; therefore, what’s stamped on a battery—10 years, for instance—is most likely going to last only four to five years for us.”

Virtua Health was determined to find a technology that was more reliable, less hazardous, less toxic to the environment, and that had fewer disposal issues. Vasquez contacted Oliver Ulibas, Program Manager with Vycon Inc., of Cerritos, CA, to check out that company’s technology.

“Batteries are notorious for requiring a lot of maintenance and testing,” says Ulibas. “When you place as many as forty batteries—each at least the size of the one in your car—maintenance and replacement is a real issue to deal with. It’s a bear.”

All UPS systems use batteries to provide the ride-through when utilities have disturbances, according to Ulibas, and the two types of battery technology generally used in the UPS industry include the sealed or maintenance-free lead acid battery and flooded lead acid batteries. The flooded lead acid batteries are contained in polycarbonate jars in order to see the lead plates and sulfuric acid within the battery. They can also leak and require a great deal of maintenance according to Ulibas. “Whether sealed or flooded, when you have 40 of them in a series and one fails to open, that basically breaks the link,” says Ulibas. “You are relying on the quality of those batteries to provide you with uninterrupted power. One major problem with batteries is that it is very difficult to determine when a battery cell is open.

“In the worst case, a customer will only find out that there is a problem with the battery when there is a disturbance with the utility and they do not have the back-up or ride-through. Also, the service life of a battery is not the same as its design life. A 10-year battery typically lasts only three to five years depending on how often it is discharged, quality of maintenance, and operating environment.”

In December 2005, Virtua Health moved ahead to the Vycon VDC140 bearingless flywheel energy storage system to be better able to protect its services during utility power disturbances. “So far everything from setup to service on the flywheel system has been great,” says Vasquez.

“This technology will save Virtua money by providing clean, reliable power for 15 to 20 years compared to the typical battery-driven technology life cycle of five to seven years,” says Thawley.

Vasquez feels that right now is a good time to be involved with the flywheel technology. “We spend a lot of money on battery maintenance lately,” says Vasquez. “And we just added another string of batteries to our system. The great thing about Vycon’s flywheel is that it picks up all the surges and everything else before it hits the batteries. Now, before anything happens, the flywheel maintains power until our generator turns on; this in turn shuts off the flywheel.”

“We are definitely eliminating at least one string of batteries to cut both our battery replacement and our maintenance in half. We are also considering the purchase of two flywheels to back each other up through a daisy chain arrangement,” says Vasquez.”

The only problem Vasquez experienced with the flywheel system has been an oil leak. He says that VYCON responded quickly to fix this situation. He also noted that the system continued to operate with no problems whatsoever even during the leak. “An oil leak is nothing compared to some of the situations we’ve experienced with the batteries.”

The power system at Virtua Health’s Gibbsboro, NJ, facility uses UPSs that protect the servers from utility power disturbances. Automatic Transfer Switches (ATS), detect utility power loss, and command the generator to automatically start during outages. Vycon’s VDC140 is in operation with a UPS, providing ride-through power while the generator starts in such a power loss or disturbance so servers are kept online. The VDC140 operates in tandem with lead acid batteries. The VDC140 remains the first line of defense. It’s designed to be discharged before the batteries, thus providing power to the UPS during most power disturbances.

Discharged only if the generator does not start, the battery DC source reduces the cycles the batteries are subjected to, extending battery life. Initial tests and actual power outages at the site have shown that during transfers to the generator, the VDC140 performed as expected providing ride-through power.

“We’re extremely pleased at having achieved this key milestone,” says Tony Aoun, Vycon president. “Installation was simple—performance flawless—during commissioning, startup, and through several real power outages. We’re confident Vycon products will perform as expected and look forward to many future installations.”

Virtua Health sees the need to be ahead in all aspects of the medical services it’s involved with today, including backup power. Vice President and CIO John Bloomer even classified such uninterrupted power as being as vital as the air they breathe. He also considers Vycon’s new generation bearingless flywheel technology important for how it has reduced Virtua’s operating costs and maintenance schedules.

“We’ve been able to reinvest in other critical areas,” says Bloomer. “We’ll be relying more on this technology as we consolidate and build new battery-free data centers.”

Virtua Health is building a new facility in Voorhees Township, NJ, and plans to use Vycon’s flywheel technology in that facility too. The coming center will feature the latest healthcare technology and host a paper-light environment. In addition to clinical services, the new facility will also include a new data center. “We definitely want to bring this new technology that has worked so well for us, to our new facility,” says Vasquez.

Thawley describes the facility as a state-of-the-art “digital hospital.” And, Virtua will be a state-of-the-art facility built on a greenfield area adjacent to a golf course. Virtua will be doing everything from generating its own power to supplying chilled water and steam. All these systems will be designed to use the new flywheel technology, according to Thawley. “This is our first experience with flywheel technology and it has proved to be very beneficial to us.”

Because Virtua recently installed two sets of battery strings, they are able to compare their flywheel system and their associated batteries to the batteries that don’t have flywheel associated to them, whenever their system takes a power hit. “We are getting side by side real-time comparisons in all sorts of power situations,” says Thawley. “At the end of this study we’re going to have excellent data to publish in order to reveal some findings on the benefits of the flywheel technology.”

With their new data system, Virtua expects to have two UPSs with three flywheels. “The flywheel, in a nutshell, is a safer alternative to the battery power,” says Thawley. “We don’t have to worry about leaks or adding to the country’s growing industrial pollution problems with the flywheel technology as we do with batteries. The Vycon system is basically a rotor or flywheel with an active magnetic bearing system, spinning continuously at 36,000 rpm in a vacuum—that controls the power.

Even with the lifespan of the flywheels being 15-20 years, this technology is still more expensive up front than batteries, according to Thawley. But a bigger plus is the fact that the technology is so much cleaner and environmentally friendly, fitting with Virtua’s mission of protecting everyone’s health in the first place.

Low-Cycle Flywheel
Vycon has a low-cycle flywheel and a high-cycle flywheel. Despite a similarity in size, the functionality of the two are different, as well as the power ratings. The low-cycle product is primarily marketable in the uninterruptible power supply sector. Essentially, the reason these are characterized in this way is that the number of outages that happen in the US per year breaks down to approximately one or two outages per month. Outage time is typically less than a few seconds.

Vycon sets its system with a genset (generator set) upstream, a transfer switch, a UPS and then the flywheel, which is tied to the UPS. Therefore, whenever there is an interruption of power, if it is long enough, the transfer switch would signal the generator to start up and synchronize. While synchronization is occurring with the power being provided from the flywheel, the flywheel is actually the source bridging that gap until the generator set can come online and take over to provide the power.

The flywheels have onboard real-time monitoring systems, so it is possible to see whether the flywheel is operational or not. If there are no faults or problems with the flywheel, it will operate. “Instead of being a reactive way of looking at your solution, which is somewhat how battery systems operate (you don’t know until you actually need them that they’re out because of one battery being out), in the case of the flywheel you know at all times whether or not your system is OK.

“A significant portion of the market out there is looking for solutions to the problems associated with batteries, and one of those solutions is the flywheel technology,” says Solis. Solis asserts that though there are other flywheel technologies on the market, the way they differentiate themselves is the fact that they have a very low maintenance flywheel. Vycon’s flywheel system is 100% reliant on magnetic bearings. That means when their flywheel is operating under normal operations they do not rely on the traditional type of ball-bearing system for rotation. Essentially theirs is a no-contact rotating assembly.

“We have a 20-year life flywheel that requires zero maintenance,” say Solis. “The problem with traditional ball-bearing flywheels is that they require significant maintenance, as the ball bearings need to be replaced a multitude of times during the 20-year life, versus ours where the flywheel is 100% levitated on magnetic bearings and there is no necessity for ball bearings under normal operations.”

High-Cycle Flywheel
Solis is focused mainly on the high-cycle applications Vycon produces, particularly those uses in the crane industry, such as rubber-tired gantry cranes or the large quay side cranes. “Every time a container is hoisted there’s a peak power, either from the rubber-tired gantry crane or from the large quay side or ship-to-shore cranes,” says Solis. “Where our product comes into action is with cranes that have AC hoist motors and there is regenerative breaking energy that can be captured and reused. At the moment, this regenerative braking energy is being wasted and dumped into resistor banks. Instead of getting rid of that energy into the resistors, it can be taken into one of our flywheels. I will then use that to recharge my flywheel and upon the next lift cycle I will discharge my energy, effectively reducing the peak power.”

In the case of rubber-tired gantry cranes, both fuel consumption and emission may be reduced. Containers typically have a duty cycle that includes lifting and handling approximately once every minute. During unloading operations the cycle can run one to two minutes per duty cycle. The current systems contain an oversized generator set to handle the peak power.

“Now the cranes can go to a much smaller generator set and save an additional amount of fuel,” says Solis. “Simply by adding our flywheel system we can show a 20–25% fuel reduction. For the crane industry we are taking advantage of the regenerative braking energy available at such sites. Instead of simply wasting that good energy into the resistor bank, we’re absorbing the energy and then discharging it during every lift cycle.”

This presents a clear opportunity for utility savings, as the port operators are no longer being charged for peak power consumption. From a grid standpoint this is significant. The large cranes are using a megawatt’s worth of peak power each minute. The charges come because this is a big issue for the utilities, according to Solis. “The reduction on the grid side is one plus and the other comes on the mobile side where we can effectively reduce the fuel consumption as well as emissions associated with these cranes—which has become a growing environmental concern,” says Solis. “There is a big push going on now to make the ports green.”

Vycon is the sole high-cycle provider for flywheels at the present time, according to Solis. They are preparing to launch their beta stage. This features the supplying of flywheels to three different sites worldwide to test and evaluate the flywheels in order to begin production in the third quarter of this year.

Vycon was established in January 2003, a spin-off from their parent company, Calnetix. Calnetix is an R&D house with a specialty in developing motor generator designs along with the magnetic bearing technologies and associated software controls. “They saw an opportunity to enter the flywheel niche, so they spun-off Vycon,” say Solis. “All the intellectual property associated with that technology was transferred over from Calnetix to Vycon.”

Ulibas says though this is an innovative product, it is not really new from a technology standpoint. “But our approach to this technology allows us to have a product that we feel is more reliable than other flywheel technologies out there.”

The flywheel is assembled in the company’s Cerritos factory in California. While Vycon has used a lot of proven materials to develop its own controls and flywheel, the company’s core expertise remains in the flywheel and magnetic bearings. But they also must have a vacuum pump, magnetic bearing controllers, circuit breakers and power switches. “The nice thing about our product is that we are using these components from well-established companies that have been in the industry a long time,” says Ulibas.

“A company can purchase single components for a bidirectional power switch, design their own gate drives, take Insulated Gate Bipolar Transistors, (IGBTs), mount them on a heat sink and basically design the whole thing. But we’ve left it up to the experts to do that for us.”

Vycon buys products from Semikron International, a Nuremberg, Germany-based company that not only designs power semiconductors, but also designs power bridges. Because that’s Semikron’s expertise, Ulibas feels it is much more reliable than something they could put together themselves. “This way, we put our effort into our core expertise which is the flywheel design, the controls behind it and the magnetic bearings,” says Ulibas.

Differences in Vycon’s flywheel products may be seen through the applications involved. Within the UPS industry the requirement is for Vycon to be able to discharge and have enough backup time for a generator to come up, run, get up to speed, stabilize and be able to take on the load. “In the power quality industry you don’t expect that to happen as often as you may in something such as unloading a container ship in port,” says Ulibas. “In that case you are making the product work continuously, or in high cycle mode at all times. In the UPS industry we don’t expect a complete cycle more than once every 15 minutes because of the quality of the power.”

Multiple power disturbances may occur, but they are typically very short in duration. A complete discharge, therefore, is not always needed. When a complete discharge is needed it is generally for a complete outage rather than a simple glitch or brownout. The low-cycle flywheel product line that Vycon produces does not require the providing of power and being able to recharge in a very short period of time, as in the case of the high-cycle crane product line. The crane product line requirement is for that flywheel to cycle power every minute.

In the UPS industry, from a quality standpoint, the low-cycle flywheel product is not required to work as hard. In the wake of Hurricane Katrina, Ulibas heard a lot of talk about the possibilities of backup redundant power being able to be available immediately for disaster recovery. “But we actually don’t have anything up in the region where the hurricanes hit,” says Ulibas. “There have been a lot of discussions, though, on the need for products like ours, as well as UPS systems, generators—and being able to bridge the gap.”

PETER HILDERBRANDT is a writer specializing in science and engineering topics.

DE - September/October 2006