Uninterruptible Power Supplies: The Case for Moving Beyond Batteries

June 27, 2016 By Carl Weinschenk

cleansourceFor something that only is used for short periods of time, companies – especially those performing mission-critical tasks – pay a lot of attention to uninterruptible power supplies (UPSes).

The main goal of a UPS is to instantaneously provide power if the main source – generally the grid – goes offline. A properly working UPS can lead to an orderly shutdown of the system it serves or, more often, bridge to backup generators or other sources.

The majority of UPSes – as high as 90 percent — are battery-based, according to Mark Ascolese, the CEO and President of Active Power. The drawbacks to this approach, he told Energy Manager Today, is they are less than completely reliable, require replacement of many elements on an ongoing basis and are comprised of environmentally unfriendly elements that are difficult to handle and dispose of.

Of course, Active Power has alternative product to sell: Flywheel-based UPSes. Ascolese says that the 10 percent non-battery slice of the UPS segment is about equally comprised of flywheel and diesel rotary uninterruptible (DRUPS) approaches.

The way in which Active Power’s CleanSource-branded approach works is relatively straight forward. It uses a flywheel, a rotating device that stores kinetic energy that can be released when needed. The only moving part is the a spinning steel rotor which continuously runs in a vacuum-based enclosure. The enclosure has a diameter of about 3 feet and a height of 14 or 15 inches. When the main power source is functioning normally, system acts as a motor and stores kinetic energy. If the source is disrupted — for instance, if the grid goes down — the motor is transformed into a generator through non-physical magnetic and electrical changes. It immediately provides power to the devices to which it is linked.

Active Power makes two main interrelated claims: It says that it is cheaper and cleaner than legacy battery-based approaches.

Battery technology, pushed by the automotive and to a lesser extent onsite power generation, has evolved during the past decade. However, the basic physics and chemistry remain. Or, as Ascolese puts it, “Batteries are batteries are batteries.” He means that batteries remain the product of a production process that is costly and not green. They require significant ongoing maintenance, contain caustic chemicals, include components that must be replaced during the device’s life and come with extensive disposal requirements. They also demand significant amounts of space and climate controlled rooms.

The flywheel approach, Ascolese said, is clean, space-efficient and has no maintenance requirements beyond replacement of the rotor bearings every five years.

Ascolese paints a picture in which all the arrows point to flywheel-based technology (and, of course, Active Power). He points to clients such as Verizon, Oracle and other big name companies. Indeed, he says that many now charge themselves a carbon tax and and, when they go over the limit, invest an equivalent amount of money into green equipment and procedures.

In many cases, he says, the drawback is legacy thinking. “If we get in front of C-level individual, a person who cares about money and environmental issues, it’s a good thing,” he said. “Things are moving along. If we start out talking to a person…whose entire career involved only battery solutions, things are not in such good shape. It takes a change in mindset to go from something deployed for decades to something that looks somewhat new.”

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