“To me, whether there's carbon or not in the energy we're using is far more important than where it comes from,” said Bill McKibben, lecturer and environmentalist author of “Eaarth: Making a Life on a Tough New Planet.”
Plug it in
Another leading candidate to replace gasoline is the electric car.
Backed by a multi-billion-dollar investment from American taxpayers, General Motors has developed the Chevy Volt, the first hybrid electric vehicle that can be plugged into a regular power outlet.
Honda, Nissan, Toyota and other manufacturers also are developing their own versions of the electric car.
“I've been concerned about the national energy solution for decades, and all the way I've had to make sacrifices,” said Chad Schwitter, president of Seattle-based Plug-In America, which promotes electric vehicles.
“It wasn't until I got into an electric car that I could do a lot for my country and not make sacrifices. I can drive a better car than the alternative. Electric cars are fun to drive. They are smooth and quiet.”
In its current form, electric vehicles are being developed mostly for passenger and commuter vehicles and are not widely available for larger applications such as trucks or buses.
Even so, passenger cars represent the majority of the country's transportation fuel usage.
“The technological improvements seem to be pretty constant,” Schwitter said. “It's like buying a computer. You know that next year's model will be faster and cheaper, but if you wait to buy the better model next year, you'll never get one.”
Schwitter said electric cars, natural gas vehicles and other options are complementary, not competitors.
“Our transportation puzzle is so large that there is certainly room for more than one fuel type,” he said.
Instead of trying to create an entirely new system, others are trying to improve the system the country already uses.
The Obama Administration in August unveiled strict Corporate Average Fuel Economy, or CAFE standards, which would require each car manufacturer's fleet of new vehicles to average 54.5 miles per gallon in 2025, up from 28.6 miles per gallon at the end of last year.
The administration estimated the changes will save families up to $7,400 on fuel over the life of a vehicle.
President Barack Obama said the regulations “represent the single most important step” his administration has taken to reduce U.S. dependence on foreign oil.
Romney and other Republicans have opposed the tougher fuel standards, saying the required technology will increase the price of new vehicles by several thousand dollars.
“The rule finalized today by the Obama Administration will hurt American consumers by forcing them to drive more expensive and less safe automobiles,” Rep. Darrell Issa, R-Calif., said in a statement after the new standards were announced. “I support the goal of higher fuel efficiency, but this rule will only add to the burdens American small businesses and middle-class families face under the heavy hand of the Obama Administration.”
Another option is the increased use of fuel made from corn or other plant-based materials.
A George W. Bush administration-era mandate requires that an increasing amount of ethanol must be produced and blended with gasoline each year. The standards call for 13 billion gallons of ethanol this year and almost 14 billion gallons next year.
Researchers at Oklahoma State University, the University of Oklahoma and the Samuel Roberts Noble Foundation in Ardmore are working to develop a plant that would allow the industry to meet the federal requirements without using corn or other plants used in food. Their research is focused on thin, tough so-called “cellulosic” plants such as switchgrass, a plant that is natural to this part of the country and that can be cultivated.
“I don't believe corn is the viable way forward for biofuels,” said Stephen McKeever, Oklahoma State University's vice president for research and technology transfer. “With cellulosic ethanol, it's quite different. You're using the rest of the plant that goes to waste.”
All of the above
The best option might just be a combination of several alternatives, said John Pinkerton, executive chairman of Fort Worth-based natural gas company Range Resources.
“Today, 96 percent of our transportation is run off crude oil. That's a bad energy policy,” Pinkerton said. “That's like putting 96 percent of your 401(k) in one stock. We have to diversify our fuel supply.”
U.S. has no refinery shortage
While the country is importing oil, it is not experiencing a shortage of refined products.
In 2011, about 29 percent of the country's total energy usage came from oil imported from outside North America. That amounts to about 5.4 million barrels of oil per day.
Over the past 15 years, the country's refinery capacity has gradually increased to 17.2 million barrels per day as refineries have expanded. The country's refinery utilization rates are cyclical, peaking in the summer and falling through the winter. Over the past year, utilization topped out at nearly 93 percent in July, up from 86 percent in February.