Uncrewed Systems Technology 043 l Auve Tech Iseauto taxi l Charging focus l Advanced Navigation Hydrus l UGVs insight l MVVS 116 l Windracers ULTRA l CES 2022 show report l ECUs focus I Distant Imagery

34 Dossier | Auve Tech Iseauto “We’ve also found now that we get up to 10 hours of hydrogen with the tanks we’ve installed, using some of the volume previously allocated to the battery pack below the middle of the vehicle,” Mossov adds. “The pack shrinks by about 80%, from 16 kWh down to 3 kWh, just to stabilise the current output, provide some back-up power and absorb energy recouped through regenerative braking. “And the volume of space freed up by switching from lithium-ion batteries to hydrogen tanks now contains 30% more energy than before. That’s 60 litres of hydrogen tanks, which weighs 30% less, plus refuelling or replacing them takes less than 2 minutes. “While there are understandable misgivings about efficiency losses when producing hydrogen gas as an energy carrier, when you consider the efficiency you regain from how much further vehicles can travel and how much lighter they get, mathematically it really becomes worthwhile. So going the hydrogen way really does open up the possibility for 24/7 operations, even if it does entail a higher initial investment.” The second reason Auve Tech has pursued hydrogen-electric propulsion is that it has noticed the growing support for hydrogen as an energy carrier in large vehicles such as buses and coaches, which it is argued cannot run on batteries alone. This complementary demand for hydrogen increases the viability of a future hydrogen energy economy and infrastructure that its taxis could use alongside hydrogen-electric buses and coaches without competing directly with either. One potential technological drawback lies in the slow start-up time of hydrogen fuel cells. Once powered on, it is not unusual for standard, high-temperature PEM fuel cells (PEMFCs) to need 15-20 minutes to warm up before the optimal internal temperature (often ranging between 100 and 180 C) for maintaining an appropriately humid environment for their electrochemical reaction and hence current output. While that is nowhere near the 6 hour charge time of the battery-electric version, Auve Tech’s engineers feel this ‘waiting time’ could still prohibit the convenience and service quality of this transport solution. The Iseauto therefore has a unique workaround for this: a low-temperature PEMFC. It can operate with an internal environment below 100 C without needing to warm up to the temperatures of conventional PEMFCs. “A team at the University of Tartu developed special materials with a proprietary design for this new kind of fuel cell,” Mossov says. “We are collaborating with them to offer the possibility of trialling and using their technology on a large scale and in a commercial context, and iterate their materials to bring their manufacturing costs down, before they go public with what they’ve invented. “We might continue using it in April/May 2022 | Unmanned Systems Technology In addition to its all-electric powertrain, Auve Tech has tested hydrogen power in the Iseauto as a more climate-stable alternative to batteries