Supplying electricity to military bases in austere combat zones can present huge logistics and transportation challenges. During a recent deployment to Iraq, Army Lt. Col. Rich O’Connor, who commanded the support squadron for the 3rd Armored Cavalry Regiment, required many large generators to supply electricity to the unit’s base camp there.
“To power a grid is astronomic,” he told an industry conference. “We need to start moving towards alternative fuel capability.”
Developers of fuel cell technologies are confident that they can answer the call.
One company currently trying to garner attention from military energy planners says that molten carbonate fuel cells could produce enough electricity at highly efficient rates and with low emissions, which would make them suitable for powering military bases in remote locations.
Molten carbonate fuel cells have been developed for natural gas and coal-based power plants for electrical utility, industrial and military applications.
Ansaldo Fuel Cells, based in Genoa, Italy, has produced a molten carbonate fuel cell that fits on a flatbed truck and can generate one megawatt of electricity on natural gas. A 1-megawatt capacity power plant produces enough electricity to power 750 households. Work is in progress to increase that generating capacity to 4 megawatts and above by using fuels rich in hydrogen and carbon monoxide, said Ansaldo officials during a recent briefing.
The technology has a 50 percent electrical efficiency rate, they said. If the waste heat is also utilized by the system, the efficiency can reach 85 percent.
Fuel cells, on a basic level, produce electricity through a chemical reaction that takes place at two electrodes — the positively charged cathode and the negatively charged anode. Hydrogen atoms enter the anode and are stripped of their electrons, becoming ionized hydrogen atoms. The electrons are routed through wires to provide electrical current as the hydrogen ions pass through an electrolyte to the cathode, where the ions and the electrons combine with oxygen to form water — the emission that makes such power generators “greener” than conventional electricity plants.
There are several types of fuel cells. Molten carbonate fuel cells, as the name implies, use compounds of lithium-potassium carbonate salts as the electrolyte. When heated to approximately 1,200 degrees Fahrenheit, the salts melt into a liquid state. Though the nickel catalyst that these systems use are less expensive than others, the fuel cells require additional carbon dioxide to replenish the carbonate ions that are used up in the reactions.
Ansaldo officials said what sets their fuel cell design apart from the competition is the company’s “twin stack configuration.” Such an arrangement separates critical components and cuts down on costs, they said.
To derive pure hydrogen from fuel requires a reformer. The reforming process can occur within or outside the fuel cell stack. Internal reformers benefit from the heat generated from inside the stack while external reformers give operators the flexibility to change catalysts without altering the stack design to accommodate different types of fuels.
Ansaldo claims that its “modular integrated reformer” combines the advantages of both designs. Because it is internal to the vessel that contains the stack, the reformer uses the fuel cell’s generated heat to sustain the reforming process so external heat is unnecessary. But it still permits catalysts to be exchanged without impacting the stack design.
“We can easily replace the reforming catalyst, so that we can reconstitute the power plant to be able to run on different fuel,” said Bartolomeo Marcenaro, business development manager for Ansaldo.
“This is one of the major technical issues that allow us to say we can run on many, many different types of fuels.”
The fuel cell can operate on the hydrogen and carbon monoxide obtained from natural gas. The company plans to test reforming ethanol, diesel and other fuels in the near future.
When coupled with a micro turbine, the fuel cell can generate extra electrical power. “This means it can be started during a blackout or at a remote base where there’s no connection” to a power grid, said Marcenaro.
Molten carbonate fuel cells, however, produce carbon dioxide exhaust. While supporters of this technology say the carbon dioxide can be harvested and recycled, this remains a controversial issue in the industry.
Ansaldo contends that its fuel cell can take readily available military fuels, such as JP-8, and convert it into power at an efficiency of 30 to 50 percent more than conventional generating equipment. The military “can increase the amount of kilowatt hours they’re able to take out of source fuel,” said Marcenaro. That would reduce the amount of fuel services would need to haul to bases.
For Navy ships, the fuel cell could provide silent propulsion, said company officials.
“This is an advantage that we think will give the Navy the ability to operate quietly and stealthily when they need to,” said Stephen Bryen, president of Finmeccanica Inc., the U.S. branch of Italy’s largest industrial corporation. Ansaldo is a Finmeccanica company.
Though U.S. Navy analysts are calling for a switch to nuclear power and other alternative fuels on ships to wean the service off its fossil fuel dependency, proponents of Ansaldo’s technology say the fuel cell offers a safer alternative that could be ready within the next four years.
“The hydrogen unit is not going to provide 100 percent of the power of the ship. But it’s going to provide a lot of power that you can use very efficiently for your auxiliary power, for operating the ship and for cruising,” said Bryen.
Rough estimates of the 1-megawatt fuel cell stand at $2.5 million, but the price tag likely will decrease as the technology improves and moves into production, said company officials.
Ansaldo has established three prototype power plants — two in Italy and one in Spain — that run on natural gas. It is installing another plant in Turkey that will run on F-76 diesel — the fuel commonly used by NATO and U.S. Navy ships — to demonstrate the capabilities of the technology on naval fuel. The project is being co-sponsored by the Turkish and Italian navies. Marcenaro said the next step will be to put the fuel cell aboard a ship.
Ansaldo has signed an agreement with Italy’s pulp and paper manufacturing industry to bring online three molten carbonate fuel cell power plants that turn factory waste byproducts into heat and electricity. The first demonstration will be a one-megawatt plant. The company plans to develop two additional plants that each would run at 4 megawatts.
By 2008, Ansaldo plans to have one of its fuel cells installed on a passenger and cargo ferry running between Turkey and Greece. The unit will provide auxiliary power by generating a half-megawatt of electricity using diesel fuel.
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