Measuring Energy Consumption For Electric Cars
- Feb 26, 2018 4:40 pm GMT
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With their array of sensors and sophisticated computer systems, self-driving cars are being touted as a way to reduce greenhouse gas emissions through efficient road systems.
Not all elements of self-driving car systems are efficient, however. A new study by the University of Michigan and researchers at Ford Motors has measured power consuming elements within self-driving systems and delineated power hogs within self-driving car systems. Their study measured energy consumption for self-driving car systems on conventional and all-electric Ford Focus systems.
Typically, small and medium equipment self-driving sensor systems, such as the ones used by Tesla Model s, required 2.8% to 4% more power as compared to the power requirements for standard cars. On an overall basis, however, their use reduced power by between 6 percent to 9 percent. Not surprisingly, electric vehicles racked up extra points in energy reduction because they use a renewable energy source to generate power. Alphabet Inc. subsidiary Waymo’s equipment was the most expensive in terms of energy used. According to the study, the equipment increased power consumption by 5%.
In an interview with IEEE, the study’s lead author Greg Keoleian said that their modeled packages overstate power consumption by future systems, which include the likes of street maps. These are expected to become more efficient over time. Bandwidths are also expected to become more efficient over time as 5G networks take over. Then there are the efficiencies in transportation and traffic brought about the cars due to platooning of traffic as well as less aerodynamic drag thanks to changes in their design.
Offsetting these gains, however, is the rise in energy consumption due to increased usage of self-driving vehicles. The idea of getting work done and not not sitting behind the wheel for hours on stretch might entice longer and more frequent commutes and cause more power consumption.
There is also the question of level of autonomy. Waymo’s self-driving car systems are considered the best in the industry and it is likely that the company will be a major player in the industry in the near future. It has already inked partnerships with the likes of Ford to establish industry linkages. Unless their systems become efficient in energy consumption, it is difficult to imagine a reduction in greenhouse gas emissions.
There is a large degree of uncertainty regarding the energy consumption of self-driving cars. Even the Department of Energy’s research has broad range estimates for their adoption. According to the agency, automated vehicles could reduce energy consumption in transportation by as much as 90% or increase it by 200%.
An earlier University of Leeds study found that changes in vehicle design, vehicle operations, and optimizing transport systems through automation could all contribute to energy efficiency in self-driving cars. But the study found that the biggest benefits to energy consumption from automation came in vehicles that were not fully autonomous. “Stopping short of fully self-driving cars may be more beneficial from an energy perspective,” the study’s authors wrote.