Fuel Cells Power Military Bases

July 2010
By Rita Boland, SIGNAL Magazine

 

Three 5-kilowatt Plug Power Proton Exchange Membrane (PEM) fuel cells provide power at Brooks City-Base, San Antonio, Texas. The U.S. Army Corps of Engineers Engineer Research and Development Center Construction Engineering Research Laboratory (ERDC-CERL) is working to supply more fuel cells to military bases and federal facilities to reduce costs and fossil-fuel usage.

Facilities benefit from reduced cost, improved efficiency and enhanced security by trading fossil fuels for newer technologies.

Hydrogen-powered cars may be the rage in the commercial sector, but the U.S. military is employing the first element of the periodic table to provide energy beyond transportation. The U.S. Army Corps of Engineers is powering stateside installations as well as bases in forward operating locations with fuel cells—electrochemical cells that convert fuel sources into electric currents. The efforts result in money savings, a reduction of the dependence on foreign oil, essentially unlimited power generation and a cleaner environment.

The Corps of Engineers Engineer Research and Development Center Construction Engineering Research Laboratory (ERDC-CERL) includes an energy branch that installs, deploys and identifies new power technologies for fixed installations. The branch began its fuel cell research in the mid 1990s, and it focuses primarily on stationary fuel cells, which have two main uses: prime power and backup power. For prime power use, installations employ the tools to provide electricity for buildings. Some fuel cells also can pull double duty. In addition to providing heating through electrochemical reactions, they can be combined with an absorption chiller that uses the excess heat from the fuel cell to cool the building. The result is a single fuel cell that can supply electricity, heat and cooling to a building.

For backup power, installations can connect fuel cells to a grid so the energy sources will kick in during an emergency without a disruption in electrical services. This ensures the continued operation of mission critical resources such as computer rooms, telephone switching equipment, command centers, hospitals and emergency centers.

Nick Josefik, a mechanical engineer at the ERDC-CERL, says that over the years the laboratory has installed more than 200 fuel cells in various sizes. These range from 500-watt models that back up a few computers to 250- to 500-megawatt systems that can power entire subdivisions, hospitals or industrial buildings. The fuel cell installations are split almost evenly between prime power and backup power use. Through this work, CERL is helping the military meet its goal to reduce energy usage 25 percent by 2015.

Josefik explains that two of CERL’s main goals are to meet the power needs of installations and to enhance the renewable technology industry. “If they have a need we want to fix it or solve it,” he states. The overall mission at CERL is to push toward sustainable installations.

In addition to putting the fuel cells in place on Army posts, CERL personnel have installed them on other military branch bases as well as federal buildings and in national parks. At YosemiteNational Park in California, power generation has to be balanced against pollution limits. Thousands of people drive their cars in the area each year, so the park had to find ways to reduce its carbon footprint. Fuel cells generate few to no greenhouse gases and produce no carbon monoxide, making them cleaner than combustion technologies. They also lose less heat during the electricity-generating process, which helps to make them more efficient than combustion generators.

Josefik explains that when fuel cells use hydrogen as the power source, the only emission is water. However, not all fuel cells use hydrogen, though he states that it is the popular belief. “It’s a marketing problem with the fuel cell industry,” Josefik states. All proton exchange membrane fuel cells need hydrogen, but others can use different substances as the charge carrier.

All CERL-installed fuel cells are powered by hydrogen, but not necessarily in its pure form. Other power sources include natural gas and propane. “We’ve looked into ethanol, but haven’t been successful there yet,” he shares. Scientists also have conducted methanol research as well as some projects that use methane from wastewater treatment plants. The fuel cells running on natural gas or propane pull out the hydrogen component and feed that into the fuel cell stack—several fuel cells grouped together to produce more power—that requires hydrogen flow.

In terms of civilian use, propane and natural gas are more accessible for the general public than pure hydrogen. For example, many houses in the United States already have a natural gas pipeline, and propane is easy to acquire and transport.

Hydrogen also is relatively easy to obtain, but generally must be procured through compressed gas dealers. To provide a continuous source of fuel, it has to be delivered in bottles regularly. Josefik says researchers are working on ways to make hydrogen more available. Because CERL is a research organization, it tests different fuel types, but Josefik says most units installed on military bases use straight hydrogen. Natural gas is the second-most common fuel source, with fewer units employing propane.

Using fuel cells connected to a natural gas line as backup generators for installations offers the benefit of continuous power. As long as the line continues to provide the fuel, the generator will continue to run. Fuel cells trump battery banks as a power source because batteries decline over time even when not in use. “If you connect to a natural gas line, it could be unlimited time of operation,” Josefik explains. Even choosing bottled hydrogen as the fuel source offers benefits over batteries because users know exactly how long the fuel cells will operate based on the amount of hydrogen stored.

 

The inside workings of a 5-kilowatt Plug Power PEM fuel cell at a Champaign, Illinois, facility are shown here.

In addition to installing fuel cells on military facilities stateside, CERL also is conducting experiments to power bases overseas. SilentCamp is a system concept in which a diesel generator is coupled with an electrolyzer, hydrogen storage system and fuel cell to power forward base camps silently. By feeding excess power from generators to electrolyzers, the generators run at higher efficiency. Electrolyzers are devices that turn water into hydrogen and oxygen, and the resulting hydrogen can be stored and used by fuel cells. The project could improve traditional generators; reduce noise, heat and chemical pollution; lessen maintenance costs; and fuel hydrogen vehicles. “That’s really an exciting, ongoing project,” Josefik says.

The work involves examining the combination of generators with fuel cells, helping generators run at their most efficient point. Users also could turn the generators off at times and only use the fuel cell. For example, when soldiers need to sleep, they could turn off the generator so power flows silently. Fuel cells create no noise and generate little heat. However, before technologies deploy to forward operating locations, they have to be proven. Josefik says that deployed technologies must meet the highest standards to ensure the protection of warfighters. He explains that one reason some of these renewable technologies slowly make their way to forward operating bases is because they lack the robustness of technologies that have been in existence for long periods of time.

Another CERL project, currently in its final stages, is the Advanced Power and Energy Program conducted in conjunction with the University of California-Irvine. Military goals of the work include advancing the fuel flexibility of solid oxide fuel cell systems for Defense Department applications as well as investigating the performance and durability of hybrid fuel cell gas turbine systems for military applications. Another focus is on technology transfer from the U.S. Department of Energy (DOE) to Defense Department deployment.

A project just starting involves a partnership between the laboratory and the DOE. A broad agency announcement has gone out for installing backup power fuel cells for emergency operation of critical applications at federal facilities. CERL has identified 15 host sites at military locations and DOE laboratories. The partners still are reviewing applications and will begin installing the fuel cells over the next year. So far, about 75 have been identified for installation.

CERL has worked with the host sites to have them determine the electrical loads they want to power during emergency situations. Josefik describes this as the “spear point” of rolling out more fuel cell technology. After those locations become familiar with the technology, he hopes to see a snowball effect in which CERL and its partners will install the power sources in many more locations.

Though CERL focuses on installations, Josefik says the military and civilian sectors have many applications that could benefit from fuel cell use. Because they can produce energy ranging from microwatts to megawatts, fuel cells can apply to a variety of technologies. “The possibilities are limitless,” he states. One area of research involves making fuel cells portable enough so they could replace electrical batteries in almost any device, including laptops. Scientists also are studying the use of fuel cells in forklifts. “Research is showing that dollar for dollar, they can compete against a battery-powered forklift,” Josefik says.

During an eight-hour shift, forklifts powered by battery lose speed and lifting capacity. Fuel-cell forklifts, on the other hand, maintain those capabilities. Locations that have multiple forklifts generally need twice as many batteries as machines so they can use one and charge another at the same time. Fuel cells could reduce that need. Another more common application for fuel cells is in motor vehicles. “The research [question] is how do we get more of those in the field,” Josefik explains. Researchers are debating a chicken-and-egg scenario, trying to determine whether to create the fueling stations or the vehicles first.

Looking toward the future, Josefik says fuel-cell costs are decreasing thanks in part to continuous improvement in material durability. The materials also are becoming less expensive. “There’s been a lot of incremental progress,” he explains. “There hasn’t been that whiz-bang iPod phenomenon with mass market presentation in the last year or couple of years.” Rather, he adds, that time has been a period of continuous growth. 

In addition to fuel cells, CERL’s energy branch is researching other renewable technologies such as solar panels, wind turbines and a technology called a flow battery, which is an energy storage device. “Fuel cells can be one part of an energy solution,” Josefik says. Some of the research focuses on combining technologies to create better power systems. For example, solar power is intermittent, but if people use the sun to create hydrogen and then they store it, they can run a fuel cell during the night to supply continuous energy.

One of the focuses of CERL is to publish as much data about its experiments as possible. The laboratory makes information about renewable energy products available to the public so civilians can use the technologies. Josefik explains that when laboratory personnel deploy and test technologies, they monitor how well they work, how much they cost and how durable they are so they can feed the answers back to industry.

Combining technologies also can serve as protection efforts. Josefik explains that laboratory personnel always examine security both of people on installations and of energy sources. By installing what is called distributed generation, experts can put electrical sources right at locations, eliminating power lines that are vulnerable to accident or attack. Generating power on site at stateside and forward operating locations also dispenses with the need to deliver fuel.

Web Resources:
ERDC-CERL Fuel Cell Team Guiding Documents: http://dodfuelcell.cecer.army.mil/references.php
ERDC-CERL Fuel Cell Programs Overview: http://dodfuelcell.cecer.army.mil/rd/index.php
Yosemite Air Quality Information: www.nps.gov/yose/naturescience/airquality.htm
Department of Energy Fuel Cells: www.hydrogen.energy.gov/fuel_cells.html