Fuel Economy: The Single Most Effective Step for Cutting Oil Dependence
The following is part of a presentation given by Union of Concerned Scientists Vehicles Engineer Donald MacKenzie at the PowerShift energy alternatives event in Lawrence, Kansas April 29, 2006.
Increasing fuel economy is by far the best tool we have for cutting our oil dependence. It will deliver fast results. It has been proven to work from experience—we roughly doubled the fuel economy of our cars between the 1970s and the late 1980s. We can do this right now. The technology needed to increase the average fuel economy of our cars and trucks to 40 miles per gallon (mpg) has already been developed, but for the most part is collecting dust on automakers' shelves.
If we increased fuel economy to 40 mpg over 10 years, then within 15 years we would have saved more oil than we would ever get out of the Arctic Wildlife Refuge over its entire 40-50 year life. And the savings from better fuel economy would keep on growing indefinitely, while the oil wells would dry up.
The pink curve on this graph shows the amount of oil we could displace under an aggressive scenario for biofuels or other alternative fuels development. These results are based on work the Union of Concerned Scientists did in conjunction with Natural Resources Defense Council and several universities and national labs. They represent an optimistic case, assuming we do everything right on both the policy and technology fronts. The biofuels in this case are a combination of cellulosic ethanol and Fischer-Tropsch fuels. Cellulosic ethanol is made from cellulose, the fibrous material found in plants, rather than the starchy, edible part of the grain that is used to make ethanol currently. The long-term potential for corn grain ethanol is fairly limited—we already use about 10 percent of our corn crop to displace less than three percent of our gasoline needs—but it is a key part of transitioning to cellulosic ethanol.
As you can see, in the near term, the savings are not as big from ethanol as from fuel economy, but what happens in the longer term as we layer these savings on top of the fuel economy savings?
The top edge of the blue area on this graph indicates the total gasoline demand for our cars and light trucks under a business-as-usual scenario—with population continuing to grow, people driving more miles, and fuel economy staying the same. Without improvements in fuel economy or reduction in miles traveled, our gasoline demand would nearly double from less than 150 billion gallons to nearly 300 billion gallons by 2050. But, if we increase to 40 mpg in 10 years, continue with some modest fuel economy improvements beyond that date, and also add in some policies to help reduce miles traveled, we can save all of the oil in the blue area. Our projected demand would drop to the line between the blue and the green, i.e., it would level off at a lower level than where we are today.
Now, the green area represents the potential savings from ethanol, if everything goes well in growing that industry (i.e., we are successful in more than doubling the tons-per-acre yield of cellulosic feedstocks from our farmlands, and in more than doubling the gallons-per-ton yield of biofuels from the feedstocks, and we can expand capacity rapidly). Many other alternative fuels, such as clean hydrogen or renewable electricity, would likely follow similar trends.
Through 2025, the savings are relatively small, since we are basically trying to grow a cellulosic ethanol industry from scratch. In the later years, after 2025, that investment can pay off, as the amount of biofuels we make grows quickly. In about 40 years, it is possible that we would need almost no petroleum-based fuels for our cars and trucks due to the combination of higher fuel economy, less travel, and new fuels. However, it's important to note that between 2045 and 2050, the growth of biofuels slows dramatically—this is where we would start to expect some serious land use competition between energy crops and food crops.
The importance of fuel economy is therefore twofold. First, it delivers bigger savings in the near to medium term. Second, it makes it conceivable that biofuels could almost completely replace gasoline for our cars and trucks in the long term because we would need much less fuel.
Over the past 20 years, automakers have used advancements in technology to add more than 800 pounds to the average vehicle and nearly double horsepower, while fuel economy has been allowed to slip. Today we have ample technology to preserve or improve current size, utility, performance, and safety characteristics, while increasing fuel economy to 40 mpg within 10 years. And over the next 20 years, hybrid technology can deliver even greater gains in fuel economy. This will provide the groundwork for us to make effective use of alternative fuels in the future, and will give us time to sort out some of the challenges associated with a shift to alternative fuels.
