Power generation and power backup are at the forefront of today’s business continuity plans as the nation’s power grid becomes increasingly overburdened and antiquated. Battery-based uninterruptible power supplies (UPSs), long the mainstay of corporate America when protecting sensitive IT and telecommunications systems
against power failures, must now be able to weather longer power outages and increasingly poor power quality. In more and more cases, neither batteries nor engine generators can offer practical or economical solutions for critical applications that require long runtimes. Reliability, space constraints, battery disposal and environmental concerns are significant drivers for developing and deploying a better solution. Key applications for long duration backup power include:
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- Telecommunication power markets (e.g. cell towers, repeaters);
- Strategically important Internetworking equipment and distributed network components;
- Concentrated, business-critical corporate networks;
- Financial markets involving real-time transaction processing;
- 911 and other emergency call centers;
- Sensitive industrial processes and instrumentation;
- Security systems;
- Traffic control and monitoring; and
- Any activity where business continuity is essential.
A new hybrid solution offers a promising alternative for these power requirements. By integrating proven UPS technology with the latest generation of zero-emission proton exchange membrane (PEM) fuel cell modules, users can achieve virtually unlimited backup power for their most vital systems. After several years of anticipation, these innovative systems are now here and offer a viable solution to the decaying utility infrastructure. Using an established UPS topology with a cutting-edge energy source addresses the limitations faced by incumbent technology.
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Next Generation Reliability
In developing a new generation of power protection equipment, reliability is the foremost concern. Configuring a 19-inch rack optimized Digital Quality on-line UPS with PEM fuel cells gives users the dependability of traditional UPS electronics in a backup power system that offers much needed extended backup times in a relatively compact space. These systems not only reduce the dependence on batteries – always the weakest link in any power protection scheme, they also offer an additional layer of redundancy by having two energy sources. Ballard Power Systems, long at the forefront of developing and manufacturing PEM fuel cells, has optimized its scaleable Nexa® RM Series 1kW fuel cell modules to integrate with MGE UPS SYSTEMS’ Pulsar EX 3200RT 3kVA double conversion on-line UPS. Fueled with hydrogen, the fuel cell UPS can provide virtually unlimited backup time as long as hydrogen is available. The hydrogen, which is contained in replaceable cylinders, is piped directly to the fuel cell module. (In the near future, internal hydrogen canisters may replace external cylinders.) Like a battery, the fuel cell module produces DC voltage that is then bussed to the UPS. Scaleable fuel cell modules are ideally suited to meet the needs of the UPS and telecommunications markets, where the limitations of batteries (inadequate run times, maintenance requirements, weight, floor space, etc.) have long presented difficulties for applications requiring backup times in excess of one hour. Installed in an industry standard 19-inch rack, the power modules include electrical connections, N+1 redundancy capability, and a host of safety features. Each 1kW fuel cell module has ±24VDC output, produces 40A of current and can be operated in parallel for power levels up to 50kW. Three of the 85-pound, 5U (8.7-inch) fuel cell modules are used in the UPS configuration. The on-line Pulsar EX 3200 RT UPS uses only 2U (3.5 inches) of rack space and weighs 82.7 pounds. It includes hot-swappable internal batteries to address momentary power disturbances and provide continuous power during the transition to fuel cell operation, connectors to accept DC input from the fuel cell modules, and six standard 15A NEMA receptacles for easy connection of critical equipment. Power distribution options with additional receptacles are also available. Connectivity is another advantage of using existing UPS technology. The Pulsar EX RT system incorporates standard USB and serial ports while offering SNMP/web connection options for advanced monitoring and control with sophisticated UPS power management software that would not be available with a standalone fuel cell product.
The fuel cell/UPS approach to extended runtime backup power produces no harmful emissions and can eliminate the need for expensive and noisy engine generators - which in many regions are heavily restricted due to local environmental regulations. The new system also does away with the need for large banks of high-maintenance batteries. In sharp contrast to batteries which must be stored in a climate-controlled environment, hydrogen fuel storage requires virtually no maintenance and can be located in almost any well-ventilated area, indoors or out. In addition, fuel cells do not see the same level of performance degradation as lead-acid batteries when operated below 20°C, or life degradation when operated significantly above that temperature. The higher energy density of hydrogen and high power density of fuel cells means that systems will occupy less space than equivalent battery-based configurations. In the event of prolonged or repetitive power outages in quick succession, hydrogen cylinders can be refueled or replaced in minutes while large battery banks can require hours or days to recharge. For added flexibility, the UPS fuel cell systems are easily and independently scalable for both power and energy by including additional UPS/fuel cell modules to increase power or adding hydrogen cylinders for expanded energy needs. And, because these systems are optimized for long-duration backup times, they are ideal for peak shaving applications where users intentionally switch to an alternative power source to reduce demand on the utility grid. In many areas, this can allow companies to lower utility costs by minimizing consumption of utility power during expensive peak usage times.
Telecommunication systems, small servers, financial transaction systems, call centers, security, process control and factory automation can all benefit from this new approach in emergency backup power. Telecommunication operations will especially benefit from the 4-8+ hour backup they require for ‘reliability of service.’ Integration of the fuel cell UPS, can eliminate the extensive space, environmental resources and maintenance demands required by large banks of high-maintenance VRLA battery strings.
Cost of Ownership
Until recently the cost of fuel cell-based products was prohibitive, but as the technology has matured, the cost of ownership has dropped significantly and, in some applications, becomes competitive with conventional backup strategies. Over a 10-year operating life, a UPS equipped with enough batteries to provide 4-hours of backup time requires a budget of more than $11,000 per kW. Costs include the price of the UPS, batteries, battery charger and monitor, and battery replacement – a large component of the budget. By comparison, the total cost of ownership for a comparable fuel cell-based UPS over the same period is roughly $10,000 (including fuel) with prices expected to go down as volumes increase and more systems are deployed. For critical applications, it can be easy to justify this cost against the potential revenue-loss during a prolonged blackout. A recent study by the Electric Power Research Institute (EPRI) noted that power disturbances cost U.S. industry as much as $188 billion per year in lost data, material and productivity. In order to minimize these losses, annual spending on backup power systems exceeds $5 billion worldwide, according to industry analysts at the Darnell Group.
The increasingly competitive cost structure coupled with numerous technical advantages, will lead to enhanced developments in hydrogen fuel infrastructure for telecommunication sites, computer rooms and data centers much as today’s architectural and engineering firms design for water, HVAC, AC power and cabling.
