The backhoe dug deep into the ground, all part of the routine work involved with building a new runway extension at Concord Regional Airport. Unfortunately, the machine's blade cut into a power line feeding a major part of Charlotte, NC, the busy city located about 15 minutes northeast of the airport.

The accident, which took place in mid-2003, shut off power to a good chunk of the city, turning off traffic signals, streetlamps, and the living room and office lights of countless homes and businesses.

Yet the instrument landing system at Concord Regional Airport didn't miss a beat. Its runway lights never flickered. Its terminal building stayed bright even as much of Charlotte did not.

The reason? Three backup power generators supplied by Waukesha, WI­based Generac Power Systems and installed at strategic locations in the airport back in 1999. The power outage provided the first real test of the generators' effectiveness, and officials at the airport were thrilled with the results.

"It is extremely important for us to stay open at all times," says Richard Lewis, aviation director at Concord Regional. "Without the backup power we would be at the mercy of other places and of the elements. If the power goes out in other places, it could knock out the power here. Having the backup generators is a major part of our ability to provide services to our customers at all times."

Concord Regional is not unusual in relying on a backup source of power. Regional airports are steadily playing a larger role in the air transportation plans of the United States. By the fall of 2001, regional jets served 192 cities and towns across the country, say officials with the Regional Air Service Initiative. By the same year, more than one out of every eight passengers on airliners flying across the United States flew on regional aircraft, the group says. As these regional facilities take on increased responsibility for serving the nation's travelers, officials at them have become more concerned with being able to offer reliable service. A major component of this service, of course, is being able to keep the lights on, the control tower functioning, and the message boards working.

It's no surprise, then, that such power providers as Generac are finding that regional airports have become steady customers. And with officials at the Regional Air Service Initiative predicting that even more cities will soon house regional airports, it's a good bet that power firms will generate even greater amounts of business from them. These providers of power, though, also understand that airport jobs come with their own set of challenges. Fortunately, officials with both Generac and Concord Regional Airport spoke with Distributed Energy about these challenges and how they met them. Their story provides a valuable lesson to other power providers hoping to do business with regional airports.

The Project

Before contracting with Generac, the Concord Regional Airport did not have a source of backup power. So what did airport officials rely on should a massive ice storm hit the region, topple tower lines, and shut off the power?

Not much, as it turns out.

"We depended on luck," Lewis says. "And we hoped that the power company would come out as quickly as possible. Needless to say, this didn't provide us with much confidence."

Obviously, this wouldn't do. Besides serving business and vacation travelers, Concord Regional is also the home airport for the members of several NASCAR auto-racing teams. During racing season, team members fly from the airport every Thursday afternoon for weekend races held across the country. Before flying out, team members spend hours working on their cars, tinkering with them often until the very last minute before their flight is scheduled.

"They cut their times very thin," Lewis says. "They don't want to leave their shops any earlier than they have to. We need to be able to provide an airport that has what they need. Everything must be operational at all times so that they can take off on time. That's just another reason why backup power is so important to us."

To handle the task of providing this power, airport officials called on Generac. The Wisconsin company is one of the country's largest independent providers of engine-driven generator systems, providing engines producing from 3 to 6,000 kilowatts of power for industrial, commercial, and residential clients. The company has been designing power-generation equipment for more than 42 years.

Airports, though, are specialized clients. Concord Regional was no exception, and officials at Generac had to consider some very specific questions before deciding which generators to install at which locations at the sprawling airport located along busy Interstate 85.

Don Vanderbrook, director of application engineering and inside sales with Generac, says that airport officials first considered what key elements of the airport absolutely had to remain up and running should the power go out and what other areas could be dark in an outage without causing major inconvenience to travelers or, even more importantly, endangering their safety.

The airport staff, in conjunction with the local Generac dealer, came up with the answer: The guidance systems, airport lighting, and security features were critical. They must stay on-line should a power outage sweep through the airport.

After analyzing the airport and its needs, the Generac dealer developed an appropriate plan to provide the facility with backup power. Generac officials next had to decide which generator models would best serve each of the airport's key areas. To do this, they looked at the kind of power load each generator would need to handle.

"We have to consider the load. Is the generator going to have to handle a basic building load, or is it going to have to handle a lot of heavy starting or in-rush current needs?" Vanderbrook says. "We have to size the generator properly to make sure it can handle its job."

Officials with the company also had to consider the job that each generator needed to do.

"What does the customer want that specific generator to do?" Vanderbrook says. "Can the load withstand the voltage dip? Are there critical items that would go off-line if there happens to be a big voltage dip?"

After analyzing the airport and its needs, Generac officials developed an appropriate plan to provide the facility with backup power. The plan included the use of three separate standby generators.

The Plan

Cabarrus County, NC, home to the Concord Regional Airport, is growing at a rapid pace. Residents are attracted to the rolling hills northeast of Charlotte and the new businesses that have steadily sprouted here. The county is known as a center of stock car racing and is home to almost a dozen NASCAR racing teams. It is also the site of the Lowe's Motor Speedway, one of the best-known racetracks in the country.

The Concord Regional Airport has also grown, which is not surprising considering that it sits in the heart of the highest-impact growth corridor in North Carolina. The facility averages more than 5,500 arrivals and departures every month, peaking at more than 7,000 during May as major events take place at the Lowe's Motor Speedway. Open since 1994, the airport serves as the home to 170 aircraft.

The airport grounds cover 750 acres and include a main terminal building, 11 hangars, a fueling facility, a City of Concord fire station, and a business park.

To keep all these separate parts running, airport officials now rely on three standby generators provided by Generac.

The 18,000 - square foot terminal building has, since being built in 1994, served as the nerve center of the airport. It includes a concourse for arriving and departing passengers, an operations center, and offices. Generac officials selected a 250-kilowatt diesel generator set with a 405-gallon fuel tank and an automatic transfer switch. The generator has enough fuel to run for more than 20 hours at full load if necessary.

Generac's second onsite generator is a 100-kilowatt diesel genset that provides backup power for the airport's instrument landing system, navigational equipment, and runway lights. This generator guarantees that the airport can continue to guide incoming flights even if normal power is interrupted.

The third Generac unit is a 45-kilowatt LP gas-fueled genset that provides standby power for the airport's fuel farm. This unit, if the power does go out, will keep the fueling facility fully operational until utility power is restored.

Premium Power Systems of Concord, in conjunction with a local electrical contractor, installed the units. And officials at Concord report that they've had no problems with backup power ever since.

"The main thing is to have something available in case the power does go out. It's one of those things that you hope you don't have to use, but if you do need to, it's nice to know that it's here," Lewis says. "It's funny. We usually think of something like tornadoes or hurricanes or ice storms as what will cause power service to be disrupted. But in our case, the time we did have to rely on backup power it was due to the error of a contractor working on a project. It can be something as simple, then, as a car going off the road, hitting a pole, and knocking out the circuits. It's a nice feeling to know that we are protected."

Because the airport needs a continuous flow of power without even a short interruption, officials with Generac made certain that their generators would provide a seamless supply of energy to Concord Regional's facilities.

The way it works is simple. Take the control tower, for instance. When the electricity goes off, an uninterruptible power supply (UPS) emergency system immediately kicks on to keep the tower running for a brief period of time. Generac's backup generator then starts and begins supplying power to the tower. Once this happens, the UPS system shuts off and its batteries are recharged, ready for the next power shutoff.

"It is a seamless transition," Vanderbrook says. "No one on-site would even have to know that the power ever went off. That's the kind of service you need for a facility like this."

Installing the right equipment in the right places is an important step in providing a plan for backup power. But even doing this right doesn't guarantee that a system will work. The final component to ensure that backup generators work properly

Airport maintenance crews regularly examine the three Generac standby generators to make sure they are all working properly and each has enough fuel. The generators themselves are programmed to exercise weekly to make sure that they are always in working order.

"You can't just put them in and ignore them," Lewis says. "And unfortunately, that's what happens at a lot of facilities. We want to make sure that our generators are running properly. Any power source has to be taken care of. If you don't take care of an emergency generator, you can bet it won't work in an emergency."

Every airport requires different plans for backup power. These plans vary, mostly, depending on a facility's size and scope. An airport the size of Concord Regional, for example, can be completely covered by backup generators. Larger airports, though, such as O'Hare International Airport in Chicago and Hartsfield-Jackson Atlanta International Airport, require a more selective approach from power providers.

It's sometimes impractical for backup power systems to provide emergency power for an entire airport the size of O'Hare. In such a case, Vanderbrook says, power providers must carefully decide which parts of an airport can do without power and which cannot.

"When you're dealing with a large airport that's almost the size of a city, you have to be somewhat selective unless you are willing to put in a whole power plant," he explains. "Some of these large airports are almost cities unto themselves."

Anticipating an Even Greater Need

It is rare today for regional airports, especially those the size of Concord Regional, to lack a backup power system. Those airports that don't have backup plans generally are smaller, private airports, often run as a hobby by their owners. But Vanderbrook even sees these airports as potential clients of power providers such as Generac, especially as security concerns continue to loom large in the mind of government officials.

After all, these tiny airports could serve as feeders for smaller planes. And they conceivably could be needed to provide emergency landings for these same planes.

While the Concord Airport project focused on customer service, power suppliers working with airports in the future will probably need to focus more than ever before on security, Vanderbrook says.

The reasons for this are obvious. Since the 9/11 terrorist attacks, officials at airports and other municipal facilities are more aware of how important it is to protect the country's transportation centers. Terrorism, once an afterthought in this country, is now a focus.

Airport officials, then, might want to place their emergency generators inside buildings to provide an extra level of security. They might also seek backup power for security devices, such as scanning devices and X-ray machines.

"As we go into the new age with security issues becoming more of a dominant driver, meeting the challenges inherent in helping provide security is going to be the key in working with municipal airports and private airports," Vanderbrook says.

If airport officials, for example, want to place a generator inside a hardened building, power providers will need to work with engineering firms to make sure that the generator still cools properly and that the building provides enough ventilation.

"The major hurdle, I think, in the early part of this century is in working with folks to make sure that security products are complementary to the generators they have," Vanderbrook says. "We have to make sure that the generators work, that they don't overheat, and that they're not located in buildings with inadequate ventilation."

That, though, is the future. For now, Lewis is happy with his airport's current backup power plan. He's also not been shy about advertising to potential clients and travelers that the airport actually can provide service even during a major electrical outage.

"We actively promote our backup power systems in terms of customer service," he says. "We want our customers to know that we will always be here. Whatever happens in the community, we will be here and available."

DAN RAFTER is a technical writer based in Chesterton, IN.

DE - July/August 2004