By Steve Blankinship, Associate Editor
Increasingly over-stressed infrastructure of all kinds is causing concern in the U.S., particularly within the transportation sector. That extends to airports and the crowded skies above them. Unprecedented air space crowding coupled with an aging air traffic control system means that the need for reliable operation of air traffic control installations is more critical than ever. That puts air traffic control near the top of the list for critical power needs.The Federal Aviation Administration (FAA), a part of the U.S. Department of Transportation, is responsible for civil aviation safety. The FAA encourages and develops new aviation technology and systems of air traffic control and navigation for both civil and military aircraft.
When an interruption occurs to power supply from the grid, backup power enables the FAA to route, launch and land aircraft while avoiding diversions or groundings. The economic pressures to keep air traffic moving despite primary power outages are enormous. Airlines can lose up to $3 million for every 15 minute outage at a communication facility. The key is to find reliable backup power that avoids the drawbacks of traditional technologies, including frequent and costly maintenance schedules, emissions and noise.
Fuel cell manufacturer Plug Power collaborated with its distribution partner LOGANEnergy to install a 5 kW fuel cell system for an FAA communications facility in Georgia. It was the first facility in the United States to back up remote communications air/ground (RCAG) equipment for communication between aircraft and tower. The GenCore 5T 48-volt DC system has now been in operation at the Kaolin Field Airport in Sandersville, Ga. for a year.
This fuel cell plant provides power redundancy for air traffic control communication at a Georgia airport, the first such installation of its kind. Photo courtesy of Plug Power.
Inroads in Telecom and Utility Applications
Plug Power develops and manufactures stationary proton exchange membrane (PEM) fuel cells that supply power to the wireless, telecom and utility industries. Such backup power systems are especially useful in applications such as cellular communication and power generation sites in remote locations or in developing countries.
The GenCore system at Kaolin Field Airport is connected to the RCAG equipment in parallel with the existing backup power battery system. Both the batteries and the GenCore support the loads via an uninterruptible power supply (UPS) system. In the event of an outage, the fuel cell system provides the needed power to the communications equipment, as well as maintain the existing batteries at a fully charged state. This will allow the FAA to achieve another level of redundancy because the batteries will be able to provide another layer of protection if called upon to do so.
The PEM fuel cell plant provides solutions in two areas. As a direct source of backup power, its hydrogen storage module houses six cylinders of hydrogen – enough to provide 55 kWh of backup power. As a complement to battery technology, the fuel cell system keeps batteries at full charge during outages while greatly reducing the need for battery maintenance and replacement over time.
Although batteries and backup generators generally provide traditional power for telecommunication, utility infrastructure, residential, commercial and other buildings, their inherent limitations require alternate backup power sources. That’s because batteries have limited life spans – typically three to five years for flooded lead-acid batteries and somewhat longer for other, more expensive battery technologies. In addition, battery backup systems require regular maintenance, usually on a monthly basis. They also require frequent monitoring of remaining capacity. Engine gensets are generally regarded as being more reliable than batteries, but they too may require considerable maintenance. They also typically produce emissions and noise.
Fuel cells have become an increasingly attractive alternative backup power technology and continue to get better due to constant product development and improvements in economies-of-scale manufacturing. Fuel cell purchase and installation pricing have become equivalent to other backup power sources. However, fuel cell manufacturers believe the lifetime cost of the fuel cell will be less than half that of the older backup systems, chiefly due to the fuel cell’s less costly maintenance requirements. Minimal maintenance is typically required only every three years for the most common fuel cells now in service, and remote monitoring systems allow users to supervise prescheduled self-tests that measure readiness for service.
Fuel cells may be well suited for extended run-time situations, unlike batteries whose service capacity is limited and expandable only by adding additional units. Extending the run capability for fuel cells usually means adding fuel. PEM fuel cells (which are considered to be the most common and best tested) operate on hydrogen, which is available from industrial gas suppliers.
Fuel cells also offer flexibility in installation options. They are compact and can weigh less than 100 pounds-per-square-foot. That means they can be installed in a variety of locations, including on rooftops. They produce little noise and no polluting emissions. In operation, fuel cells produce only water and heat as byproducts and both can be captured and even reused for other purposes.
Fuel cells have proven to be highly reliable in field tests and actual use, operating through extreme outdoor conditions including high and low temperatures. And they can’t produce hazardous acid leaks like some battery backup systems can. And while at the end of their service lives batteries and engine-gensets require disposal in accordance with hazardous waste disposal guidelines, fuel cells can be “recycled” in one day to be reused without ever entering the waste-stream.
LOGANEnergy installed the fuel cell plant at Kaolin Field and specializes in designing, installing and maintaining fuel cell projects. The FAA secured its GenCore system with assistance from LOGANEnergy and Construction Engineering Research Laboratory (CERL), part of the U.S. Army Engineer Research and Development Center.