LONG BEACH, Calif. --- The National Hydrogen Association's conference this week highlighted progress in hydrogen fuel cell and internal combustion vehicles, but also explored the many challenges that remain -- such as building a widespread refueling network and increasing on-board hydrogen storage for greater driving range. This latter challenge is being addressed by a hydrogen vehicle from Energy Conversion Devices Inc. , which has now started fleet testing at the South Coast Air Quality Management District (AQMD) in Diamond Bar, Calif. A project of Ovonic Hydrogen Systems LLC, the advanced vehicle is a high-profile test bed designed to prove that hydrogen hybrids can be practical in daily life. The high-tech vehicle also serves to showcase Ovonic solid metal hydrogen storage technology. Based on a production gasoline-electric hybrid model, it is part of a five year, $7 million multi-vehicle hydrogen hybrid demonstration at AQMD. Additional ECD Ovonics hydrogen hybrids are expected to join the fleet in the coming months, and one is already in service at ECD Ovonics' headquarters in Rochester Hill, Mich. "The ECD Ovonics hydrogen hybrid will help demonstrate this emerging technology and address current storage and range limitations," said Chung Liu, D.Env., deputy executive officer of technology advancement for the South Coast AQMD. "This technology will help us expand our region's hydrogen infrastructure and serve as a stepping stone to longer-term future technologies including fuel cell vehicles." ECD Ovonics' hydrogen hybrid has been equipped with hydrogen storage tanks using the company's proprietary solid metal hydride technology, which enables hydrogen to bond at the atomic level with a powdered metal alloy inside the tanks. This technology allows storing hydrogen at much lower pressures than the 5,000 to 10,000 psi storage tanks typically used in other hydrogen vehicle applications, the company said. The result is the ability to carry a greater volume of hydrogen on-board to provide increased driving range -- in this case just under 200 miles. "That's substantially greater range than most hydrogen vehicles today, and an important milestone toward making hydrogen vehicles a practical alternative for the highway," said Robert Stempel, chairman and CEO of ECD Ovonics. "Our goal is to apply the diverse technologies based on ECD Ovonics' proprietary work to make advanced hybrid, hydrogen, and fuel cell vehicles competitive in the marketplace." ECD Ovonics' hydrogen hybrid has been turbocharged to compensate for hydrogen's lower energy density and enhance overall performance and drivability. Refueling during fleet testing is taking place at a hydrogen station at the South Coast AQMD headquarters, which has been specially modified to refuel the vehicle at a low 1,500 psi.