Drag from rooftop sensors makes Waymo’s self-driving minivan an energy hog. Photo: Wikimedia/Dllu
By driving smarter, autonomous cars have the potential to move people around and between cities with far greater efficiency. Estimates of their energy dividends, however, have largely ignored autonomous driving’s energy inputs, such as the electricity consumed by brawny on-board computers.
First-of-a-kind modeling published today by University of Michigan and Ford Motor researchers shows that autonomy’s energy pricetag is substantial — high enough to turn some autonomous cars into net energy losers.
Plugs are definitely vogue at this week’s Mondial de l’Automobile in Paris. So where does the hybrid vehicle fit into the picture? It may not, according to Renault. The French carmaker says that electric vehicles, not hybrids, are needed to deliver the emissions reductions that governments and customers demand.
And Renault is not the only major automaker planning to produce commuter-oriented EVs. Mitsubishi Motors and Daimler both announced plans in Paris last week to accelerate commercialization of small EVs — Mitsubishi with its i-MiEV minicar and Daimler with a battery version of its popular Smart Fortwo. Volkswagen’s promo materials in Paris confirmed it would join the EV club, producing a tiny commuter EV called the Up! in 2010 with a top speed of 130 kilometers/hour and roughly 100 kms of range.
Ok you say. EV’s are à la mode. But what of the hybrid option? The question is partly semantic. Hybrid technology is everywhere if you count the mild hybrids, which employ a small but potent electric battery to save gas by rebooting the combustion engine on a green light instead of idling through the red; some can also recuperate energy during breaking by recharging their battery. This technology is going mainstream: Renault competitor PSA Peugeot Citroën said it alone will install 1 million stop-start systems by 2011. VW spokesperson Martin Hube said his company viewed stop-start as just an evolution of internal combustion drive. “You can call it a mild hybrid but it’s just a smart technique,” says Hube. “That’s nothing new.”
No automaker questions whether full hybrids like the Prius or GM’s plug-in Chevy Volt that can drive on either electricity or gasoline are something new. But while several showed full hybrid concept cars in Paris, fewer talked up plans to build one. Perhaps they’ve made the same calculation as Renault: it’s not worth the trouble to cram high-energy motors, batteries and an engine into a vehicle when one can go straight to the full EV instead.