Test systems using alternative fuel source
June 7, 2012
Test systems on White Sands Missile Range are using new alternative fuel options for better, cleaner, long term power.
Utilizing fuel cell systems provided under an Operational Test Command, Army Test and Evaluation Command program test systems on WSMR have already been equipped with clean burning methanol fuel cell systems. Fuel cells, ranging in size from that of a small lunch box up to larger units about the size of a foot locker can be used to power things like communications relays, instrumentation, and data collection packages required for test operations.
The cells convert methanol, a type of alchohol, into electricity. "A direct methanol fuel cell directly converts methanol fuel into electrical energy with very high efficiency," said Henry Merhoff with Operational Test Command's Test Technology Directorate. The actual process produces very little noise, only a slight hum, a small amount of heat, and produces a small amount of waste water, all while generating electricity at a cost lower then more common technologies. "It's cost is approximately one tenth the cost of using batteries, and without the noise, thermal emissions, and carbon monoxide risks that you have with generators," said Merhoff. This allows the cells to be extremely flexible, in their deployment, as they can be used in confined spaces safely.
The two primary designs are ruggedized for military use and have an output of 250 watts for the larger unit, and 100 watts for the smaller unit. The larger unit runs at a selectable 12 or 24 volts just like a vehicle power supply, and the smaller one runs at 28 volts.
The endurance varies for each design, with the smaller cells needing to be refueled more often than the larger cells simply because the smaller cells have smaller fuel tanks. "The fuel cells runs for about a week between refills for the smaller ones. If we use the large fuel cell it has a larger tank so it runs about three weeks between refueling," said Merhoff.
To keep refueling simple, the cells fuel tanks are actually removable bottles, allowing the operator to simply replace the entire tank. Empty tanks can then be disposed of or recycled, though tanks that haven't been emptied may require some hazmat disposal regulations be followed.
Developed over the last eight years the cells have gone from a laboratory concept to production units ready for use. "These units we have here are at technology readiness level nine, which means they are production units that have been deployed and used in an operational environment," said Merhoff. Currently OTC has about 90 production units that can be deployed in support of operational testing or other appropriate ATEC activities.
At this time the power cells use is somewhat limited to supporting testing and other similar functions, due to the logistical limitations of the fuel they use. While a clean and efficient fuel source, the Army doesn't yet classify methanol as a tactical fuel source, so the Army doesn't have the acquisition and logistical requirement to get the fuel to deployed units. Stateside this isn't as big an issue, and it's possible the cells could see more use in programs requiring high endurance power supplies.
On WSMR the cells are already seeing use powering test operations in support of programs like Patriot Missile testing and the Network Integration Evaluations.