How Battery Energy Storage Complements UPS Performance

Credit: iStock/Kaligraf

One power outage without the benefit of a reliable backup system can cost a company millions of dollars.

An August 2016 power outage at Delta Airlines’ Atlanta hub, during which key systems failed to switch over to backup power and grounded airplanes and stranded passengers, put a public face on a challenge that commercial and industrial operations face daily. When it comes to power and backing it up, it’s a matter of hoping for the best and preparing for the worst.

The return on having a reliable power backup system outweighs the investment when an incident does occur. Aviation experts predicted that the Delta Airlines glitch would cost the company millions of dollars. That’s just one incident with one company.

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A 2013 White House report, “Economic Benefits of Increasing Electric Grid Resilience to Weather Outages,” shows the average cost to the economy is $18 billion to $33 billion a year just from weather-related outages.

Jim Gordon, national account manager for engineering consultants in the mission critical field for Enersys, points out that most facilities need some type of backup to keep running if utility power goes down, and that’s the function of an uninterruptible power supply (UPS).

“You need something to keep running until the generator kicks on to keep the inverters running and that’s why batteries are required,” he adds.

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“We have problems in the United States with our grid. It’s susceptible to failure here and there,” says Gordon, adding that infrastructure in the northeast US is particularly aged.

“That’s where microgrids and the idea of the smart grid and other green technologies is coming up. All of those need batteries in one way or another. Solar needs them to hold the power—those are usually a DC-based product and can be turned into AC. With wind, you need it to run the controls as well as doing some grid storage in peak shaving.”

Thomas Panozzo knows well the benefits of a reliable UPS backup system. He’s the chief technical officer for Data Realty in South Bend, IN. The data center serves as both a co-location facility and a data processing facility running heavy data analytics workloads for a variety of clients.

“We have hundreds of companies that house their critical infrastructure with us. That’s infrastructure that supports their global operations,” he points out. “We have to be up and running all of the time. There is no option to not be.” Data Realty uses two Mitsubishi Electric Power Products, Inc. (MEPPI) 9900B UPS systems for its growing data center operations.

There are a number of factors to consider when deciding upon the appropriate type and size of a UPS system. Consider current and future power requirements, efficiency, and total cost of ownership, says Dean Datre, general manager, UPS division, MEPPI. Other factors to consider: uptime requirements and whether a single-module or parallel (redundant plus one) system is needed, notes Greg Mack, vice president and general manager of the TIC Power Electronics Division.

The incoming electrical service, the electrical requirements of the attached critical load, customer efficiency requirements, “and more importantly whether the customer needs to add UPS capacity in the future,” are other considerations, notes Brian Kennedy, senior product marketing manager, for Vertiv.

“UPS solutions can be designed utilizing internal redundancy, system redundancy, or a combination of both and these systems can be designed for dedicated reserve, shared reserve, or distributed reserve architecture,”  he adds.

Another factor is the critical load equipment in kilowatts, he says, adding that to help determine these factors, TIC offers a mobile application on Android devices, enabling end-users to configure and plan UPS installations based on such factors as battery runtime, battery current, output current, output kW, output kVA, input current, input kW, and input kVA.

Also consider the end-use specific application, environment, load size and type, backup run time, alternating current (AC) availability, a location’s physical layout and footprint, voltage and frequency, redundancy, seismic conditions, topology, and sound requirements.

“There are typically certain requirements that will drive a project besides price,” notes Kyle P. Ellenberger, regional sales manager, Power Systems & Controls.

There are three main factors that drive the UPS selection process, he says, with the first being the need for electrical isolation. Case in point: an area with a high chance of lightning, such as Florida and Arizona.

The second: a need for redundancy, such as in the case of data storage and processing. Third is a need for an industrial solution, as in the case of environments Ellenberger calls “dirty and abusive,” such as oil rigs and manufacturing.

“The majority of UPS systems go into ideal environments like data centers, but there is still a billion-dollar market for non-data applications such as 24/7 manufacturing processes, chemicals, and oil,” he adds.

When deciding on the type and size of the UPS solution, users must consider their unique needs and which solutions will best address those needs, says Ed Spears, Eaton’s technical marketing manager.

“Eaton’s UPS solutions are categorized based on protecting the nine most common power problems present in any environment,” he says, adding that Eaton offers three levels of power protection.

Backup power is offered by Series 3 Standby UPS. “These UPSs primarily protect against three of the nine power problems including power failures, power sags, and power surges,” says Spears. “This essential, cost-effective protection is necessary in order to prevent damage such as data loss, file corruption, hardware damage, and equipment shutoff.”

For example, all work in progress can be lost if a utility fails. The Series 3 UPS offers a degree of protection against the remaining power problems and is most commonly used to protect single workstations and point-of-sale equipment.

Keeping power smooth is addressed through the Series 5 Line Interactive UPS. “These UPSs are most effective against five power problems—power failures, power sags, power surges, under-voltage, and over-voltage—and offer a degree of protection against other power problems,” says Spears.

Some of the damages risked by not using that type of UPS include premature hardware failure, data loss and corruption, data error, keyboard lockup, storage loss, and system lockup, he adds.

The Series 5 UPSs can be used in small network systems to enterprise networking environments.

Total protection is provided by the Series 9 On Line Double Conversion UPS, which protects against all nine power problems: power failures, power sags, power surges, under-voltage, over-voltage, line noise, frequency variation, switching transients, and harmonic distortion.

The comprehensive protection minimizes the opportunity for component stress, burnt circuit boards, data crashes, and program failures; and offers optimal power protection for mission-critical applications such as server farms, hospitals, and Voice Over Internet Protocol applications, says Spears.

There are several steps to follow when considering UPS sizing, says Spears. They include:

  • List all equipment to be protected by the UPS, including monitors, external hard drives, routers, and other components.
  • List the amps and volts for each device. These ratings can typically be found on the label on the back of the equipment. Multiply amps by volts to determine VoltAmps (VA). Some devices may list their power requirements in watts. To convert watts to VA, divide the watts by power factor. For servers, the power factor is often 0.9.
  • Multiply the VA by the number of pieces of equipment to get the VA subtotals.
  • Add the VA subtotals together.
  • Multiply the total by 1.2 to get the grand total. This step accounts for future expansion. Use the grand total to select a UPS. When choosing a UPS, be sure the total VA requirement of supported equipment does not exceed the VA rating of the UPS.

Credit: Fotolia
A three-dimensional rendering of a server room with black servers

Eaton also has a number of resources available to help users in the selection process, one of which is the Eaton UPS Selector tool, which walks users through a step-by-step process and displays options that fit the requirements. The company also has a white paper that weighs the considerations of choosing between a decentralized or centralized UPS.

To correctly size a battery, one must consider the size, efficiencies, and power factors of the UPS, says Gordon.

“It comes down to a price point and what the customer’s requirements and needs are,” he says. Gordon often works with engineers to help them write specs that are supplied with the systems when they go out for a bid.

The main considerations in selecting the correct battery chemistry include power and energy needs, backup time, voltage limitations, footprint, and weight, notes Nicholas Shanley, Li-ion application engineer for Saft’s industrial standby division.

“Additionally, selecting the right technology depends on how critical the application is—the reliability factor, maintenance, temperature conditions, service and predictable life, and total cost of ownership,” he adds.

Credit: Courtesy of EnerSys
DataSafe XE batteries by EnerSys are specifically designed in response to the evolving requirements of modern critical UPS applications. With the most advanced Thin Plate Pure Lead (TPPL) technology, DataSafe XE batteries support runtimes under five minutes.

Nickel-cadmium and lithium-ion batteries have a design life of more than 20 years, points out Shanley.

The market offers numerous choices for UPS units and batteries.

MEPPI provides complete UPS systems and related peripheral products from 6 to 12 kVA single-phase and 10 to 2100 kVA in both single module and multi-module configurations, including MEGAPOD, a self-contained modular solution designed to save time and labor by allowing for shorter time to deploy power to loads.

The company also provides around-the-clock direct factory service, commissioning, factory and onsite testing services, as well as engineering and system design, Datre notes.

MEPPI’s UPS systems are not only used for power backup, but also to condition power by providing clean power to the load, notes Datre.

“Mitsubishi provides true online UPS, allowing for complete availability of clean, uninterrupted power,” he adds. “Loads are not subjected to raw utility power as may be the case in economy modes of operation.”

The 9900B UPS systems used at Data Realty are a double conversion online topology design with power ratings of 300kVA/300kW, 500kVA/500kW, 750kVA/750kW, and voltage options of 480 input and output.

The UPS features a fully digital CSTBT (IGBT) inverter and converter design, low-input harmonics, internal static bypass, three-level power conversion technology, dual input, front access, 1.1:1 generator sizing, advanced circuit topology, and PWM, board level self-diagnostics, and is available for parallel redundant and capacity applications of up to eight modules.

It has 97% efficiency at 50- to 100% load, a power factor of 1.0, and is drilled for NEMA two-hole compression lugs. It is designed to be lightweight with a small footprint and OSHPD Seismic Certification is available.

Panozzo says his operation chose the Mitsubishi systems for the smaller footprint—which frees up more space for business operations—and because they put out a lot less heat.

“They require so little cooling compared to other systems that we were able to not install as much cooling as competing data centers, so our cost is less expensive to build a facility,” he says, adding that in doing his homework on systems, he found that the Mitsubishi UPS “has had zero problems.”

Vertiv offers UPS units ranging from 500-watt desktop products through multi-megawatt systems designed for data center, commercial, healthcare, banking, education, corporate, and other markets ranging from enterprise data centers to smaller data hubs, and edge-of-network applications, says Kennedy.

Credit: NAES Corp.
The new battery monitoring system allows staff to check individual cell voltages, temperatures, and other metrics at a glance, as well as collect and report data with less risk of short circuits or exposure to chemical hazards.

Among the options: enterprise-class medium and large 3-Phase AC Power UPS solutions in the 10 to 1,200 kVA range, designed with scalable capacity and redundancy. With the exception of the smallest desktop and non-critical oriented single-phase UPS products, all of Vertiv’s enterprise class UPS solutions feature double-conversion technology.

“This, by its nature, provides energy conditioning and protection against not only power outages, but all types of potential power disturbances including sags, surges, spikes, noise, transient voltages, frequency deviation, under voltage, over voltage, and harmonic distortion,” says Kennedy.

Many of the company’s UPS solutions are Energy Star qualified and employ energy savings features such as Active Eco Mode to increase energy efficiency and lessen operating costs, says Kennedy, adding that some of the solutions operate at up to 99% efficiency.

Eaton provides UPS systems designed to help organizations protect critical IT infrastructure with backup power for everything from desktop PCs to large data centers.

Some of the latest and most recently updated Eaton UPS solutions include:

  • The Eaton 93PM UPS three-phase system, engineered to offer low total cost of ownership. It is designed to offer flexible deployment options to support integrated thermal management solutions, a compact footprint, efficiency up to 99%, and simplified energy management features. The company’s 93PM UPS portfolio includes new UL 924 models developed specifically for emergency lighting and power that range from 20 to 120 kVA, as well as auxiliary lighting and power-listed models from 20 to 200 kVA. The system is designed to offer end-users the ability to tailor lighting solutions based on existing environments and requirements while reducing operating expenses.
  • The Power Xpert 9395 UPS is designed to provide efficiency and scalable battery runtimes in a small footprint. Large data centers, healthcare applications, multi-tenant data centers, light industry, and other critical systems can lower their total cost of ownership by leveraging the Energy Saver System in conjunction with the Power Xpert 9395 UPS, notes Spears. The platform is designed to offer 99% efficiency across most loads with Eaton’s Energy Saver System, double-conversion efficiency of up to 97%, and no less than 95% efficiency at loads down to 15% with the Variable Module Management System. Eaton’s 9395 platform also features inherent redundancy engineered to share the load when power capacity is below 50 to 75% for enhanced reliability. The Power Xpert 9395 UPS portfolio includes new 200 to 600 kilowatts kW/kVA models in North America, designed to provide efficiency and advanced capabilities to reduce total cost of ownership in small- to mid-sized data centers and a scalable platform engineered to meet increasing power requirements and maintain uptime of critical systems.
  • Eaton is currently developing and testing lithium battery solutions for several UPS lines, including the 93PM and 9395 products. “These storage solutions promise significant size and weight reduction in contrast to conventional VRLA batteries while offering a longer service life,” says Spears.
  • The Eaton 9PX UPS is designed to seamlessly integrate into any IT environment to keep servers, switches, voice and data networks, and storage systems online. A graphical LCD interface provides full UPS status, energy consumption analytics, enhanced configuration capabilities, and load segment control. When paired with Eaton’s Intelligent Power Manager software, end-users can monitor and manage power devices from one dashboard from any location. Eaton recently launched the Eaton 9PX UPS in 2 to 3 kVA units. The line offers new automation options designed to help IT managers remotely manage and protect critical infrastructure while saving time and money. Eaton’s PredictPulse remote monitoring and management service is designed to monitor and analyze UPS infrastructure to enable better decision-making. “When an issue arises, Eaton calls the end-user to begin the resolution process,” says Spears.

Credit: Toshiba International Corporation
The 5000 Series N3R Uninterruptible Power System is Toshiba’s first-ever UPS designed for outdoor applications and features a NEMA 3R rated enclosure.

Eaton offers UPS units that can be utilized as power conditioners to support medical and other applications. “These latest generation systems are more modular in nature, so they can be expanded easily as needed and they provide immediate sag or surge correction response while running 2% to 3% more energy efficiently,” says Spears. “They also can be set up with redundancy in the same physical footprint, reducing the cost of an additional system in case redundancy is a requirement.”

Eaton’s 9390 UPS is one example, serving as both a UPS and a double-conversion power conditioner that resolves utility power problems and supplies clean, continuous, regulated power to connected equipment, he adds.

Ellenberger points out that there are two technologies for the UPS market that the company provides according to an end-user’s application and requirements.

“Static [solid-state] technology is an electronic solution. It utilizes a double conversion process via an inverter and rectifier to recreate the power to protect the critical load and provide the highest level of power quality possible on the output,” he says.

A rotary UPS utilizes a motor generator to recreate the power via a mechanical solution as the motor is physically driving the generator through a mechanical couple to recreate the power, says Ellenberger.

A UPS system can use either batteries or a flywheel to provide the DC power needed to provide backup power and bridge the loss of utility, Ellenberger points out.

An UPS system is usually utilized for providing power backup to critical applications, but also can be used for power conditioning, providing electrical isolation to the downstream loads, Ellenberger points out.

“The intended use usually drives the selection process as power conditioning would require a true online UPS system, not offline or line-interactive models,” he says, adding that true electrical isolation applications would demand a rotary uninterruptible power supply. His company’s mechanical coupling is designed to provide a high degree of electrical isolation.

“Many national laboratories and national security sites utilize rotary UPS systems because of their need for complete electrical isolation,” adds Ellenberger.

Toshiba International Corporation (TIC) manufactures, sells, and services single-phase and three-phase uninterruptible power systems for IT, commercial, industrial, and health care applications. Single-phase model sizes range from 1 to 22 kVA and three-phase model sizes range from 10 kVA to 2 MVA, parallelable up to 8 MVA.

Toshiba’s rechargeable 20-amp-hour cell SCiB batteries are designed for a variety of applications, including grid energy storage. The batteries, made of lithium titanate, are designed to be charged in as little as 10 minutes and its thermal performance reduces or eliminates the need for battery cooling. Its LTO chemistry is not susceptible to thermal runaway or lithium metal plating.

SCiB products also offer minimal capacity degradation after an operational life of 10,000 or more charge-discharge cycles.

TIC uninterruptible power systems are capable of providing battery backup, power conditioning, and frequency regulation solutions. The company utilizes lithium-ion technology and offers the SCiB Rechargeable Battery in 1 MW containerized storage and 25 KW energy management solutions designed for energy storage applications.

Solarcraft designs double-conversion AC-UPS or DC-UPS battery-based UPS to provide power by storage batteries during a utility power outage mostly to pipeline and refinery operations.

End-users have an application or device in a remote location “and it may be a critical piece of instrumentation where they are gathering information and if they have line power coming in, they need a backup situation,” notes Bill Mantini, technical sales for Solarcraft.

“We size their load and they will tell us how long they need the instrumentation to be backed up,” he says, adding the company supplies the appropriate amount of battery power for the calculated backup needs.

“These systems usually come in an enclosure, they have batteries and they have the power supply and sometimes also what we’re backing up goes back into AC current, so it may have an inverter in it also,” says Mantini. “They’re not huge, but they’re usually contained in a stainless steel enclosure or a mainly aluminum enclosure that sits out along the pipeline and is accessible that way.”

EnerSys focuses on the lead battery market for the US UPS industry with flooded or valve-regulated batteries.

Credit: Saft
The Intensium Flex from Saft

Among the options:

  • CYCLON batteries are designed with a resealable 50 psi safety valve to let gases escape. The valve automatically reseals to avoid risk of excessive gas accumulation within the battery or “dry out” failure from repeated recharges. The thin lead batteries are designed for greater surface area and power. High-purity acid is absorbed into the Absorbed Glass Mat plate separators to provide leak-proof operation in any position.
  • The DataSafe CX-M is a multi-cell, flat-plate battery designed for high performance and short duration discharge rates. Calcium alloy grids allow for lowest water loss. Lead-plated copper posts are designed to provide high one-minute rates. The DataSafe CX-M battery has a Slide-Lock, post-seal design. Its posts and connectors are located above the cell cover, designed to simplify maintenance routines, including individual cell monitoring and intercell resistance measurements.
  • DataSafe DX/DXC flooded lead calcium flat-plate batteries are designed for UPS in large data centers. They feature a capacity range .607 to 5,446 kW per cell, Slide-Lock post-seal design, and a wrapped positive plate for long cycle life.
  • DataSafe E batteries are medium power batteries designed with calcium alloy grids for lowest water loss, a 422 to 3322 kW/Cell and high one-minute rates for switchgear applications. They also feature a Slide-Lock post seal design and a single cell jar.
  • DataSafe HX 16v batteries feature a flame-retardant UL94 case and cover to meet UL 1778, individual flame-arresting cell vents, and brass-threaded receptacle, bolt terminal, and faston terminals. Front terminal DataSafe cabinets are designed to provide higher energy density in the cabinet. Positive and negative plate grids are made of lead-calcium-tin alloy. DataSafe HX has 100% initial battery capacity. Front terminal HX scales to larger kVA systems 550, 800, and 925 WPC.
  • DataSafe NPX batteries are designed for high-discharge applications where high wattage is required for a short duration. They feature a leak-proof operation in any position except inverted. The batteries comply with non-spillable battery regulation, per IATA special provision A67 and 49 CFR and are UL recognized with a standby-expected life of three to five years.
  • Genesis EP thin plate pure lead batteries are designed for lower corrosion rates and consistency and a wide range of applications, such as offices and hospitals. They offer a two-year shelf life and are designed with a small footprint. They also are designed to offer deep cycling capabilities, fast recharge abilities, and a non-spillable design allowing mounting in any position except inverted.
  • EnerSys also manufactures FlexSure outdoor enclosures using pre-engineered interchangeable components to enable outside plant support solutions for most equipment and power deployment configurations. It is designed with modularity for expandable architecture that can be upgraded in the field without service interruption. Common deployment applications include DSL, Broadband Loop Carrier, Digital Loop Carrier, Line Power, Wi-Fi, WiMAX, and Wireless Backhaul applications such as 3G, 4G, LTE, and Node B. The enclosures are tailored to meet NEC standards and are certified to Telcordia GR-487.

Credit: Toshiba International Corporation
A photovoltaic inverter with battery storage cabinet from Toshiba International Corporation

EnerSys recently introduced a new version of its pure lead battery for use in the UPS market. The battery is designed to last longer and run at higher temperatures.

In battery technology going forward, expect lithium to make greater headway into the market, notes Gordon, adding that such batteries have some operational and recycling issues, but that the technologies will catch up in the upcoming years as large-scale technical universities working on the challenges. EnerSys is considering a nickel-based product for future consideration.

Saft manufactures advanced battery technologies, supplying rechargeable vented and maintenance-free nickel-cadmium and lithium-ion for UPS applications.

“Nickel-cadmium batteries are widely used for the petro-chem, financial and industrial markets because of their ultra-high reliability even under extreme conditions,” notes Shanley.

The company’s lithium-ion battery systems complement its Ni-Cd product range and in addition offer a “smart,” more compact, lighter, and efficient solution, he adds.

Nickel-cadmium and lithium-ion battery systems are engineered to meet a wide range of end-user requirements, Shanley points out.

Saft offers Ni-Cd and Li-ion solutions for industrial and commercial grade UPS up to 860VDC. Power capability ranges from kW to MW with backup times ranging from minutes to hours with life expectancies exceeding 20 years at 68°F/20°C.

Credit: Vertiv
The Liebert EXM is a reliable and economical mid-size UPS system with an industry-leading efficiency rating and a modular design that enables scalable and redundant configurations.

Energy conditioning typically affects the cycle life of batteries, Shanley points out, adding that lithium-ion batteries are designed to offer optimal cycle capability.

“Standby batteries are on float charge most of their life and not cycling,” he says. “We can design our battery systems to cycle and power condition, similar to our batteries installed for PV and energy storage applications.”

A monitoring system is designed to ensure that the battery will continue to operate without skipping a beat. Real-time battery monitoring systems are used in UPS applications such as data centers, manufacturing operations, hospitals, and for emergency lighting, for example.

Such is the case with Eagle Eye Power Solution’s BMS-Series real-time, battery-monitoring systems. They monitor string voltage and current, jar/cell voltage, internal resistance, connection resistance, and temperature.

The systems come with battery management software enabling real-time battery monitoring systems to be remotely monitored 24 hours a day, 365 days via computer to help reduce downtime, maximize battery life, reduce maintenance and replacement costs, and enhance safety and security of critical battery backup systems.

Eagle Eye Power Solutions also offers battery training courses on battery maintenance and testing, battery data management, safety, and reliability in response to end-users’ requests for education on those matters, notes Eagle Eye Power Solutions spokesperson Jordan McGahan.

She points out that without proper battery testing and preventative maintenance, the electric system would be compromised, causing significant revenue loss and safety hazards within a facility. BE_bug_web

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