WEST LAFAYETTE, IN - A Purdue University economist has released two separate studies -- one on electricity costs for California electric vehicle owners, another on infrastructure requirements for the federal Renewable Fuel Standard. The studies, both overseen by Wally Tyner, underscore issues that could hinder plans to expand use of these alternative fuels for vehicles.

Tyner is an energy economist with the department of agricultural economics at Purdue University.

The California EV study concludes that policies aimed at reducing electricity use and curbing greenhouse gas emissions have the unintended consequence of making new plug-in hybrid vehicles uneconomical in the state. The other study concludes the U.S. lacks the infrastructure to meet the federal mandate for renewable fuel use with ethanol, but could meet the standard with significant increases in cellulosic and next-generation biofuels.

Tyner said California's tiered electricity pricing system means Californians will pay some of the highest electricity rates in the country to recharge plug-in hybrid vehicles. States with flat electricity rates or those that vary price based on the time of use are more economical, according to Tyner's study.

In tiered systems, consumers pay a higher rate for electricity they use beyond a certain amount. California has three rate tiers. It also has a time-of-use system, which reduces the rate during periods of low demand. In addition, Californians pay some of the highest electricity rates -- an average of 14.42 cents per kilowatt hour, which is about 35 percent higher than the national average.

"The objective of a tiered pricing system is to discourage consumption. It's meant to get you to think about turning off your lights and conserving electricity. In California, the unintended consequence is that plug-in hybrid cars won't be economical under this system," said Tyner, whose findings were published in the early online version of the journal Energy Policy. "Almost everyone in California reaches the third pricing tier each month. If they add a plug-in hybrid, they are charged the highest rate."

Tyner worked with other Purdue researchers to develop a model that would simulate energy use by Californians. They analyzed U.S. Census data to determine types of appliances each household would use. The model closely aligned with actual energy use in California. Adding a plug-in hybrid would increase the average use of electricity nearly 60 percent per household, according to the findings. In California, most of that increase would be charged at the highest rate.

Tyner said states such as Indiana, which charges a flat rate of about 8 cents per kilowatt hour, would be more economical. Those that employ time-of-use rates would be the most economical because the lower nightly rates would coincide with when people are most likely to charge their cars.

"If you have time-of-use pricing, you have the opportunity to charge the car at the lowest available price," Tyner said.

Tyner said California could change its rate system or issue extra electricity meters for charging cars on flat rates.

California was chosen to study because, given the fact that it is often at the leading edge of energy conservation policy and practices, plug-in hybrids are expected to be popular there. For the simulations, researchers compared the Chevrolet Volt with the Toyota Prius and Chevy Cobalt to estimate relative economics of the alternatives.

The researchers determined the plug-in hybrid would be less economical than the Toyota Prius, a hybrid that does not charge its battery through a plug, or the Chevrolet Cobalt, which uses only an internal combustion engine. When oil prices are high, the Prius would be the most economical, with the advantage going to the Cobalt when oil prices are low.

Tyner said to make the Volt more economical in California than either the Prius or the Cobalt, oil prices would have to rise to between $171 and $254 per barrel, depending on which electricity pricing system is being used. That's because the Volt has a higher purchase price and will cost more in electricity than gasoline over the life of the vehicle.

The simulations accounted for a $7,500 federal rebate to consumers for purchasing plug-in hybrids. Tyner said electricity costs would have to decrease to allow the plug-in hybrids to compete.

"People who view the Volt as green will pay $10,000 more over the lifetime of the car because it's green," Tyner said. "Most consumers will look at the numbers and won't pay that."

Purdue's Center for Research on Energy Systems and Policy funded this research.


In the study on infrastructure requirements for the federal Renewable Fuel Standard, Tyner worked with co-authors Frank Dooley, a Purdue professor of agricultural economics, and Daniela Viteri, a former Purdue graduate student. They used U.S. Department of Energy and Environmental Protection Agency data to conclude that the United States is at the "blending wall," the saturation point for ethanol use. Without new technology or a significant increase in infrastructure, Tyner predicts that the country will not be able to consume more ethanol than is being currently produced.

The federal Renewable Fuel Standard requires an increase of renewable fuel production to 36 billion gallons per year by 2022. About 13 billion gallons of renewable fuel was required for 2010, the same amount Tyner predicts is the threshold for U.S. infrastructure and consumption ability.

"You can't get there with ethanol," said Tyner, whose findings were published in the December issue of the American Journal of Agricultural Economics.

Tyner said there simply aren't enough flex-fuel vehicles, which use an 85 percent ethanol blend, or E85 stations to distribute more biofuels. According to EPA estimates, flex-fuel vehicles make up 7.3 million of the 240 million vehicles on the nation's roads. Of those, about 3 million of flex-fuel vehicle owners aren't even aware they can use E85 fuel.

There are only about 2,000 E85 fuel pumps in the United States, and it took more than 20 years to install them.

"Even if you could produce a whole bunch of E85, there is no way to distribute it," Tyner said. "We would need to install about 2,000 pumps per year through 2022 to do it. You're not going to go from 100 per year to 2,000 per year overnight. It's just not going to happen."

And even if the fuel could be distributed, E85 would have to be substantially cheaper than gasoline to entice consumers to use it because E85 gets lower mileage, Tyner said. If gasoline were $3 per gallon, E85 would have to be $2.34 per gallon to break even on mileage.

There is talk of increasing the maximum amount of ethanol that can be blended with gasoline for regular vehicles from 10 percent to 15 percent. But Tyner said that even if the EPA does allow it, the blending wall would be reached again in about four years.

Tyner said advances in the production of thermo-chemical biofuels, which are created by using heat to chemically alter biomass and create fuels, would be necessary to meet the Renewable Fuel Standard. He said those fuels would be similar enough to gasoline to allow unlimited blending and would increase the amount of biofuel that could be used.

"Producing the hydrocarbons directly doesn't have the infrastructure problems of ethanol, and there is no blend wall because you're producing gasoline," Tyner said. "If that comes on and works, then we get there. There is significant potential to produce drop-in hydrocarbons from cellulosic feedstocks."

The U.S. Department of Agriculture funded this research.