08/27/2009

News / Green Transport Means Fuel-Efficient Vehicles, Low-Carbon Fuels

Technology-development path promising but uncertain, scientist says

By Megan Neff
Staff Writer

Washington — Improvements to conventional cars and advanced vehicle technologies are bringing the prospects of greener transportation closer to the streets, according to a U.S. scientist.

Steve Plotkin, a staff scientist with the Argonne National Laboratory’s Center for Transportation Research, said fuel-efficient cars and other vehicles as well as low-carbon and renewable fuels are crucial components in any strategy to slow greenhouse gas and other emissions from the transport sector.

“Because vehicles are responsible for 20 [percent] to 30 percent of greenhouse emissions, and transport emissions are growing fast, it is vitally important to find ways to slow down this growth, or we will never fully address climate change,” he said. Plotkin participated in an August 19 America.gov Webchat on advanced vehicles.

There is no clear definition for what constitutes a fuel-efficient vehicle, Plotkin said, but advanced fuel-efficient technologies are generally understood as allowing at least a 10 percent reduction in fuel use compared to conventional technologies.

“That’s only for one technology. … A truly efficient car would use several technologies simultaneously,” he said. Additional technologies that improve fuel efficiency include better tires, improved aerodynamics and lightweight materials. Hybrid gasoline-electric cars have been promoted as fuel efficient.

Alternative fuels such as ethanol and biodiesel have been gaining ground in recent years. Although almost all ethanol is sold as blends, with 10 percent or less ethanol blended with gasoline, automakers are producing many new vehicles that can run on blends that have higher ethanol content.

The general public’s interest in alternative-fuel technologies and fuel-efficient vehicles has grown in recent years due to concerns about global warming and continued U.S. dependence on petroleum imports. The number of hybrids sold in the United States rose 37 times to 352,274 cars in 2007 and that of flexible-fuel vehicles by more than 50 percent to 974,095 vehicles in the same period. When U.S. petrol prices hit record levels in 2008, sales of hybrid autos spiked up. In some developed and developing countries, alternative-fuel and fuel-efficient cars are increasing their market presence at even faster rates.

The more technologically advanced options are hydrogen-based and fully electric vehicles. Both offer an alternative that is almost entirely emission-free, but they are still in development and as such are costly.

“Many technologies and fuels are expensive, especially at first,” Plotkin said. “Research must be greatly expanded to find costs savings. Otherwise, not much will happen.”

But the research and development process is fraught with unexpected difficulties and surprises, he cautioned, so some technologies may not pan out as policymakers and researchers hope they do.

“Remember that lots of promising technologies have disappeared along the path of development,” Plotkin said. “Not from conspiracy, but just lack of successes.”

Electric vehicles, for example, offer a very promising alternative to conventional autos. However, they will become a viable option only if researchers meet the challenge of developing smaller, lighter, longer-lasting and more powerful batteries. Those currently available cost at least $10,000 and must be replaced every three to five years, according to Plotkin.

In the near future, much can be done to improve the fuel efficiency, safety and performance of conventional vehicles.

“The best solution for the next 10 to 20 years will be greatly improved conventional cars,” Plotkin said. “Downsized engines, better transmissions, lighter-weight bodies, better aerodynamics, better tires.”

http://www.america.gov/st/energy-english/2009/August/20090826130627saikceinawz0.6544001.html?CP.rss=true


1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 | 157 | 158