By Claire Swedberg
Jan. 15, 2008—The state of Florida, as part of a project to acquire and utilize fuel-cell vehicles, has been employing
ZigBee-based wireless
sensor tags in the city of Orlando, to ensure the state's 14 hydrogen-powered vehicles do not leak. Users can log onto a Web site and watch the sensor results in real time. The system was designed and developed by the
University of Florida's department of chemical engineering.
This inexpensive system, says John Painter, manager of the state's hydrogen-powered fleet and project, could be utilized by dealerships throughout the country, as fuel-cell vehicles proliferate, in order to ensure that those vehicles can be safely stored and maintained. Such vehicles are powered by fuel cells that use hydrogen gas, in conjunction with oxygen from the air, to produce electricity. Because the nodes consist of off-the-shelf components, they cost very little. What's more, the nodes, a
base station, a laptop and software would be all that would be required for a user to set up a remote sensing system.
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Fan Ren
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Painter first began investigating fuel-cell vehicles as a researcher at
Ford Motor Co.. In about 2006, he was hired by the state of Florida to acquire and maintain fuel-cell vehicles. The state operates 14 Ford Focuses powered by a fuel-cell battery that consumes hydrogen gas. Some of the cars are used by the
Florida State Department of Environmental Protection, and others by utility company
Progress Energy, which operates two major utilities serving 3.1 million customers in the Carolinas and Florida.
Hydrogen is a highly explosive gas, and although Painter says the safety precautions engineered into the vehicles make them safer than gas-fueled vehicles, the state sought an added layer of protection to ensure that no hydrogen leaks would go undetected. Initially, the vehicles were stored and serviced in a covered outdoor area at Progress Energy, because of the storms that often blow into the region, at times while the cars were being serviced. The state chose to move the cars to a covered work site, which better protects them but makes hydrogen leaks a greater hazard since any gas leak would collect in the enclosed space. The covered site is part of a garage at auto dealership
Greenway Ford, located in Orlando.
Painter says he began speaking with local universities and companies about the problem two years ago, upon meeting University of Florida professors who had already developed a hydrogen sensor. One of those professors, chemical engineer Fan Ren, had worked on a system known as AlGaN/GaN High Electron Mobility Transistors (HEMTs), four years ago for
NASA—a project funded by a grant from that agency. The HEMT sensors for that project measured the presence of hydrogen around the space shuttle, but did not use any wireless transmission technology.
In August 2006, Ren says, the researchers installed six wireless sensor nodes at Greenway. A wired solution, such as that which had been installed for NASA, would have been unrealistic, he explains, noting, "It's a huge garage. It would be very difficult to put wires through there."