Powering Uninterrupted Growth
New UPS systems are another example of the ability of the latest tech tools to increase efficiency while lowering expenses.
By David Engle
Cloud computing, blade servers, virtualization, co-location: They’re among the hottest information technology (IT) trends, and like previous ones, they’re reaffirming Moore’s law: Whatever the task in view, the latest tech tools do it better and at less expense, often taking a quantum leap over whatever came before.
Meanwhile, data centers have begun reversing a notorious decade-long energy binge, and this is also transforming equipment dynamics. This industrywide campaign followed an alarming report by the US Department of Energy—published several years ago—showing that energy consumption at data centers was unsustainable.
|Photo courtesy of Active Power
Active Power’s CleanSource 300-kVa UPS
Along with the logistical challenge of doing makeovers at hundreds of IT sites, there’s the perennial pressure to control soaring site expenses. Because a UPS regulates both alternating current (AC) power usage and direct current (DC) power storage, it (and its associated resources) runs virtually non-stop. Hence, the latest UPS systems are at the center of efforts to innovate and conserve. Gaining even a few points in efficiency can return a surprisingly quick payback (more, below).
All these factors have spurred re-engineering of new UPS and energy storage solutions, especially lately, notes Chris Loeffler, Eaton’s data center applications manager.
“They’re driving us to build smaller, yet more highly powered, products, shrinking the footprint more and more,” says Loeffler.
In the broader energy-saving crash program that has ensued, several themes have emerged. Two of them are centralization and streamlining, according to a recent white paper titled “The Four Trends Driving the Future of Data Center Infrastructure Design and Management,” from UPS market-leader Emerson Liebert. A third, mentioned by several vendors, is a trend toward higher power density in backup systems. This is pushing UPS makers to offer products with ever-greater capacity. On this, Emerson Liebert’s Network Power manager Gary Anderson points out that recent years have seen a steady push far past the earliest 100-kW threshold, and on to UPS systems capacities greater than 1 MW.
|Photo courtesy of BHP Energy Solutions and Capstone
Syracuse expects its green-energy EDC to operate with just half the power consumption of a conventional data center.
Another capacity-related UPS innovation has been “intelligent paralleling,” says Anderson, and it’s done, as always, for better economies and power management. He explains: “If we have more than one UPS in parallel—and typically we want to have at least three—if a UPS is very lightly loaded at any point, we can actually turn one off altogether. We’ll put it into a sleep state so that the other two UPSs are working more efficiently.”
Another trend he notes: “Everything’s moving to IGBTs” [insulated gate bipolar transistors], power semiconductors giving higher efficiency, and faster switching. Faster IGBT switching enables greater efficiency at lower loads. A UPS is typically not efficient here, Anderson points out, so product engineers have been redesigning systems to reshape this dropoff.
“We are moving up that curve into much higher efficiency at [say], 50% load, to save end users money as well as protect the UPS from overcycling or running at very low loads.” Output variability is also enhanced with this technology, the better to match the load.
UPS power quality has also become a selectable option. Anderson, again: “We have what we call ‘intelligent eco mode’ and ‘intelligent paralleling.’ In ‘intelligent eco mode’, we run our UPS on the bypass with power protection through the inverter, because the inverter is active while we’re running it through the bypass so that we can not only protect some of the power, but we can also switch quickly to the inverter to try to isolate any issues as quickly as possible.”
To sum up, Eaton’s Loeffler surveys the recent tech scene and sees, “a lot of pieces fitting together. It’s sort of a gumbo soup—there’s everything from high-voltage DC and distribution into the data center, to very high-efficiency UPS systems.”
Further discussion on advancements in electronics follows below, but first, here are three of the more exceptional innovations that are now driving UPS capabilities.
A Prototype Hybrid UPS/CHP Plant
Alluding to data centers’ notorious energy consumption, UPS innovator David Blair points out that per square foot they’re “thirty times higher in energy consumption than a typical commercial building.” As head of a distributed energy development firm called BHP Energy, a subsidiary of GEM Incorporated (Toledo, OH), Blair and his company were spurred by this challenge when, in late 2009, they introduced to the market a potentially far-reaching single solution to data center energy needs: the first-ever hybrid UPS/combined cooling, heating, and power (CCHP) plant, at Syracuse University. The site is billed by Syracuse’s facility staff as the most sophisticated implementation of microturbine technology in the world.
The building-integrated mission-critical power system, which uses 12 hybrid UPS turbines manufactured by Capstone Turbine Corporation, is positioned at the campus Education Data Center. Installation took place in 2009, in collaboration with IBM, and with financial assistance from the New York State Energy Research and Development Authority (NYSERDA). Both organizations are keenly interested in tracking how the hybrid concept matures. As of mid-2010, the several hybrid UPS-protected loads at the school’s data center were in the process of slowly ramping up to capacity.
From Blair’s description of the system’s tasks, the “hybrid” term fits aptly. This packaged plant is built around a small 65-kW Capstone microturbine engine, fitted with hardware and controls for fully optimized CCHP. It’s also pre-equipped with rectifiers and inverters—the same elements found in any UPS that isolates critical loads or does power-conditioning of the utility line. As Capstone’s vice president of business development Steve Gillette recounts, it is this obvious similarity in electronics that suggested how the rectifiers could morph the unit into “a UPS-type solution” for data centers.
Basically, he says, the upgrade was accomplished rather easily by just adding another AC-to-DC box atop the existing ones, for a connection to the utility. With it, says Gillette, “we now have three ways to deliver power” to UPS-equipped customer sites, as follows.
First, “through our generator when it’s on,” he says. “With the generator itself, you can use it to back up the AC power [of the utility],” in the same way a diesel engine might. “You can do a UPS-style DC output—or you can switch back and forth as needed”—again, by using the already integrated electronics.
Second, “in what might be called ‘UPS mode,’ it’s taking power from the utility line, when available.” The turbine itself rests silently. But the onboard circuits continue taking the grid line power and putting it through conventional double conversion, like any UPS.
Lastly, when the line fails, the integrated switchgear shifts seamlessly to an EnerSys battery bank, storing about 17 minutes of backup power.
BHP Energy, which is a Capstone distributor and onsite power developer in the Eastern US, was the one who actually took the hybrid concept and put it into economically viable action by adding the CCHP and the building design and construction elements. The firm has now branded its whirring, multitasking hybrid the “Reliaflex” Power System—though it is not an entirely new item built from scratch. Rather, it extends an existing microturbine cooling-heating-and-power package, of which, to date, more than 30 have been installed, at sites like the Toledo Museum of Art and Seagate Convention Center. Worldwide, about 5,000 Capstones in 65-kW and 200-kW sizes have been shipped from the firm’s Chatsworth, CA, plant, during a dozen years of operation. The microturbines are also pre-certified for compliance with tough California Air Resources Board (CARB) air-quality compliance, and Underwriters Laboratories (UL) certification is pending, Blair points out.
Blair poses the question, “When was the last time you looked at a UPS and said it had a payback?” He gives a quick sketch on how such cost recovery might work out:
First, the turbine already comes equipped with high-voltage AC-DC-AC conversion and other power electronics, so a customer would not need to buy another conventional one. Second, the diesel generator that usually sits around a site, doing virtually nothing but collect dust and standby for backup emergencies, could also be eliminated—because the Capstone is capable of doing that role too. Third, the CHP plant could pay its way by occasionally eliminating even the utility bills, “depending on local rates and heating and cooling needs,” he says. Whenever grid power surpasses eight cents per kilowatt-hour, onsite generation will likely save money. The curve becomes aggressive when topping 12 cents a kilowatt-hour. This is possible because the fuel-conversion efficiency of CCHP more than doubles that of the average utility power.
In the CCHP value proposition, capturing exhaust heat is always critical. Blair points out that the Capstone turbines’ ability to serve the integrated 150-ton exhaust-fired ReliaFlex chillers means that even in summertime the exhaust heat will be of high value. Blair also envisions exporting the thermal value produced by the ReliaFlex to adjacent buildings, as is being done at Syracuse—a concept he calls being “District Energy Ready.” Year-round, heat utilization would be assured.
|Photo courtesy of BHP Energy Solutions and Capstone
CCHP turns chiller exhaust into a valuable energy source.
A second key UPS innovation these days: packing a power supply together with integral hardware and storage energy and putting it all inside a standard ISO container. It’s not unlike a carefully stocked lunch pail, and the benefits are also similar: easy portability, a good balance of compatible items, and compactness.
Active Power (Austin, TX) is one of several vendors now doing this; vice president for global channels and business development Martin Olsen explains his company’s approach:
“We take all the components that you as a customer would go out and procure if you were to build your own mission-critical infrastructure, and we put all of that together in a pre-engineered, pre-tested fashion.” A flywheel UPS, diesel generator, fuel tank, automatic switch gear, input and output distribution controls, and a monitoring overlay are positioned snugly inside.
Olsen uses the analogy of buying a car at the showroom, rather than collecting parts to assemble them yourself. Holistic integration makes the sum perform even better—more efficiently, in terms of energy, space, and cost—than if cobbled together piecemeal. Designs can be easily replicated from one container to the next. Repeatability enhances quality control; nevertheless, flexible options are also selectable, such as four sizes on power capacity. Assembly occurs in a factory, where labor is cheaper, enabling customers to gains savings of reportedly 20% to 25%, compared to buying and installing piecemeal.
Data centers also favor the box, says Olsen, to conserve interior office space; relocating the UPS furniture from inside the building to the exterior makes the box, in effect, an outdoor utility shed addition. Flywheel-equipped, the array can survive a temperature range of 0 to 104°F, he notes, compared to batteries which need a narrow climate within 68 to 77°F.
Containerizing also makes an easy way to expand existing capacity. In one recent application, a large telecom was obligated to build a 1-MW disaster recovery facility in just five months’ time. Normally that would take a year or more, but instead, two containers, “with chillers and everything, were packaged and shipped out,” says Olsen. “We had the site up and running in two months on rental equipment and a permanent one two months later.”
Wheels: Catching Up with Batteries?
Though not exactly new—having been introduced (again, by Active Power) about 10 years ago for energy storage—flywheels have been steadily evolving since. What is new, perhaps, is the claim that flywheels are closing in on the longstanding market-dominance of lead acid batteries.
Dann McKeraghan, vice president of sales for Vycon (Yorba Linda, CA) reported in autumn 2010 that “In the US over the last 12 months, demand for flywheel technology has accelerated. We’ve seen an increasing demand for our flywheel DC energy storage or ‘battery-free’ UPS systems. Year-over-year sales of VYCON DC energy storage flywheels have soared 300%, he adds. “It’s a growth industry, fueled by the need for high reliability combined with lower life cycle maintained cost, high efficiency, and ease of deployment, when compared to the alternate lead acid battery option.” Active markets for power reliability include healthcare, broadcast, telecommunications, insurance/finance, and educational institutions.
As for data centers: A mere five years ago, selling to that perpetually busy industry required educating buyers up a learning curve; flywheels had to be carefully explained or demonstrated, and years of allegiance to batteries overcome. Now though, he says, “We see specification after specification coming out as a battery-free design utilizing flywheels instead of lead acid batteries,” indicating that buyers seem to accept flywheels with confidence.
For those still uninitiated, a flywheel works by storing a very brief burst of power in its rotational momentum. That is basically all it does. Conventional utility energy keeps the wheel rolling continuously, and the attached, protected loads (data center servers or whatever) actually get their power through the whirring intermediary. If the utility fails, inertial spin keeps the wheel going another 20 seconds or so, and loads are not harmed. Meanwhile, an integrated backup generator quickly kicks on and takes over. Only five to eight seconds are needed for this; the remaining 12 “are a cushion,” says Olsen. After the backup generator is engaged, the flywheel power is restored and reverts to its normal mode of operation. All is well again, and when the utility is restored, the switch gear re-engages it and lets the generator rest.
As for wheel varieties, Vycon, together with Active Power, “are really the two players in the flywheel business,” notes Olsen, following the recent departure of Pentadyne.
Technologically, Vycon’s and Active Power’s wheels differ mainly in their respective sizes and resulting power characteristics.
Olsen explains that his product still uses essentially the same flywheel revolving on mechanical bearings in a vacuum, as in the original 1990s prototype. “Magnetic pulses from the armature spin it up, so there’s no shaft on it, though there is some [magnetic] levitation on the bottom and top,” he says. By virtue of this latter force, the wheel’s 600-pound mass lifts aerodynamically, “and that, essentially, makes it a 150-pound weight, all electronically operated” for balance and turning, at 7,700 revolutions per minute (rpm).
Vycon’s rival wheel, in contrast, employs full maglev, without a support bearing, for virtually frictionless spinning. This design yields much less wear, but different output dynamics. The floating levitated design was actually pioneered in mid-decade by Pentadyne, but proved to be somewhat exotic and perhaps vulnerable. Vycon thus adapted some characteristics of that lighter wheel, then substituted more practical elements like air cooling, a more reliable permanent magnet, and a more conventional composite material. Power-wise, to compensate for its lower energy resulting from its much lighter weight, it turns nearly 10 times faster, at 50,000 to 70,000 rpm. Vycon’s Web site lists the resulting varied runtimes produced by assorted wheel sizes, the latest of which, called the XE, bumps up the time another 20% to 30%, notes McKeraghan.
For both wheels, the chief selling points are not against each other so much as against their rival battery banks. On that score, wheels are reportedly much easier to maintain; they enjoy a much longer lifespan; and they claim greater reliability. McKeraghan suggests that his frictionless flywheel should last 20 years; by contrast, “valve-regulated batteries typically need replacement every four,” he says. This recurs, and the cost of often buying more batteries really adds up: Normally, he reports, after the first battery change-out at four years, the original cost of the flywheel is fully recouped. One estimate of the comparative life cycle savings pegs the flywheel advantage over batteries at $100,000 to $200,000 per wheel.
In batteries’ defense, though, is this: If you think you need 10 or 20 minutes’ power, as opposed to a mere 20 seconds of spinning momentum—batteries are still your only option.
In addition to measures noted above, this press for improvement is also taking place in the UPS control system for handling the efficiency curves as loads decline (as so typically happens). At 100% load, attaining high efficiency is easy, says Dean Datre, general manager of the UPS division for Mitsubishi electric power products. “But nobody runs on 100% power—more like 50% or 75%”—at which points, efficiency drops. As noted above, all UPS makers are striving to keep it high.
Eaton’s Loeffler also cites the shift to transformerless UPSes as a key innovation, dating back a bit. Eaton’s UPS also, like Emerson’s has an “Eco-mode,” for highest efficiency, and a scaled-back mode that makes the UPS less demanding on that measure but more protective against faults. Eaton’s 9395 “BladeUPS” product, released in 2007 runs at “98% or 99% efficiency, and is even pushing higher, as it is protecting loads,” says Loeffler. In 2010, the 9395 was recognized as the first UPS to attain SMaRT Gold Certification, qualifying it under the Leadership in Energy & Environmental Design (LEED) program.
Going Too Far?
On a final, cautionary note, Anderson and others point out that, while efficiency has yielded prized gains, there are cases of going overboard. Costly outages have resulted from pushing too hard. The Uptime Institute, which reports on such failures, noted six major data center crash incidents in 2008; but this figure—amidst the energy conservation blitz—then soared to 17 incidents in the first eight months of 2009. In August 2009, one high-profile financial processing center suffered a one-hour outage, followed by hours of “aftershocks.” An independent damage assessment pegged the loss at between $7 million and $32 million.
In a June 2010 survey of more than 170 data center and IT managers done by Emerson, 24% of respondents reported that they had suffered at least one power outage in the previous 12 months. (Typical causes are weather, human error, and equipment failure.) The loss impact per incident is variously estimated as high as $2 million.
Too, managers are now more worried about power failure than a few years ago: In this survey, outages were ranked as a major concern for 56% of the respondents, compared with 41% six months earlier.
Some outages “are probably caused by not having enough redundancy in place,” he suggests, or from a lack of familiarity and experience with all the newer gadgetry.
Eaton’s Jeff Ames observes that, in chasing peak efficiency, “if you’re not paying attention to how you’re shutting down and controlling loads in the event of an extended power loss, you can really put your entire operation in jeopardy.”
He concludes with a sound caution—echoing a very conservative power reliability industry mantra: “If you save money with efficiency, that’s great. But if you lose a lot of money with unplanned downtime, you could wipe out a lot of savings in a matter of minutes.”
Though, to protect against this, Ames says, “more intelligent, automated power management is being integrated into the newest UPSs to enable seamless shutdown and control of applications that we are protecting.”
UPS and power backup are also being linked directly to, and controlled by, a data center’s overall management software. Incremental load management and capacity utilization are also automated and enhanced this way, he says.
Collectively, these and other UPS improvements have raised average performance perhaps half a dozen percentage points (i.e., into the mid-90% range), compared to benchmarks a decade ago. Modest, yes. But remembering the 24/7 operation, that’s enough of an increment to give “a very quick payback on the entire cost of unit,” notes Mitsubishi’s Datre. To underscore this, in mid-2010, Mitsubishi introduced a UPS energy efficiency calculator to help customers project a repayment timeframe. Several vendors offer similar tools.
In dollar terms, gaining a few points might work out as follows: A 500-kVa UPS, powered at 13 cents per kilowatt-hour, would shave off perhaps $100 per month. “That’s $12,000 over 10 years,” multiplied by the number of UPS systems, points out Datre. And UPSs often run in banks of parallel sets.
Active Power’s marketing and sales vice president Lisa Brown also launched an online efficiency calculator in 2010, and at the time she remarked: “CIOs [chief information officers] and data center operators in particular have to manage escalating business and IT demands. And these changes almost always require delivering more power for a growing data center, at a reduced expense.”
Author's bio: Writer David Engle specializes in energy-related topics.