Are electric cars coming too soon?

Greening of the grid, manufacturing more hybrids is chicken-and-egg situation



If you’re in the market for a new car in the next few years, you’re likely to have an impressive array of options, and not just in style and trim, but in the most fundamental aspect of the car—what makes it go.

Several car manufacturers already sell hybrid electric vehicles, which combine standard combustion engines with electric motors. California-based Tesla Motors sells a completely electric sports car, and G.M., Nissan and Ford have all promised to introduce electric vehicles in 2010. Toyota says it will offer a plug-in version of its popular hybrid, the Prius, in 2012.

By shifting the fuel source from gasoline to electricity, plug-in hybrids and electric vehicles promise to reduce tailpipe emissions of carbon dioxide and other pollutants and lower the demand for imported petroleum.

But producing electricity causes pollution, too, and the prospect of using electricity for transportation on a large scale has caused some to question whether the new technology will really clean the air as much as proponents say.

So, do electric cars need a green grid?

A new kind of car

To answer the question, it’s important to understand a bit about the vehicles themselves.

Hybrids, which have been around for more than a decade, use electric motors and battery storage to improve efficiency. Electric components allow hybrids to use smaller combustion engines, shut off their engines at traffic stops and capture energy otherwise lost during braking.

Plug-in hybrids rely fully on battery power at first and then operate like conventional hybrids once the battery is depleted.

Electric cars rely completely on battery power.

G.M. is calling its Chevy Volt an “extended range” electric vehicle, although it can also be considered a plug-in hybrid. The car will have a small gasoline engine, but only to generate power for the electric motor and not to power the car directly.

Hybrids improve efficiency without changing how cars are fueled or how drivers can use them. Plug-in hybrids and electric cars get part or all of their power from the electric grid instead of gasoline and require, to varying degrees, that owners plug them in.

Cutting greenhouse gases

It’s easy to see how hybrids pollute less than conventional gasoline-powered cars of a similar style. They simply burn less gas.

Comparing electric cars to gasoline-powered cars is a little harder. Instead of looking at miles per gallon, researchers consider how much pollution is created for each mile driven. (Gasoline is made from crude oil.)

Researchers at the U.S. Department of Energy’s Argonne National Laboratory have developed a model for “well-to-wheel” energy use and emissions for various types of vehicles. They estimate that electric vehicles would reduce greenhouse gas emissions by 26 percent over gasoline-powered vehicles despite the fact that most electricity in the United States is generated with fossil fuels.

(Coal, which produces more carbon dioxide than natural gas and oil per unit of energy, accounts for about half of domestic electricity production.)

A similar assessment by the Electric Power Research Institute and the Natural Resources Defense Council found that plug-in hybrids would significantly reduce greenhouse gas emissions over the next four decades even if electricity production continued to produce large amounts of carbon dioxide.

Because of regional differences in how electricity is produced, electric cars would have a greater or lesser impact in different locations. A 2007 report prepared for the California Energy Commission found that in California, plug-in hybrids would reduce greenhouse gas emissions by 44 percent and electric cars would reduce them by 68 percent.

Tracking other pollutants

The numbers for other pollutants are mixed. Argonne estimates that electric cars would dramatically reduce emissions of carbon monoxide and volatile organic compounds in urban areas, where they are most harmful to humans, but increase overall emissions of sulfur oxides and particulate matter.

The National Research Council has issued a study examining the costs and benefits of plug-in hybrid electric vehicles and concluded that it will likely be decades before such vehicles yield benefits to overcome their higher initial costs.

The study, titled “Transitions to Alternative Transportation Technologies—Plug-in Hybrid Electric Vehicles,” concluded that costs to manufacture plug-in hybrid electric vehicles in 2010 are estimated to be as much as $18,000 more than for an equivalent conventional vehicle.

“Although a mile driven on electricity is cheaper than one driven on gasoline, it will likely take several decades before the upfront costs decline enough to be offset by lifetime fuel savings,” the council said in its Dec. 14 press release when the study was released. “Subsidies in the tens to hundreds of billions of dollars over that period will be needed if plug-ins are to achieve rapid penetration of the U.S. automotive market. Even with these efforts, plug-in hybrid electric vehicles are not expected to significantly impact oil consumption or carbon emissions before 2030.”

Assuming consumer acceptance, after 2030 plug-in hybrid electric vehicles could account for “significant reductions in U.S. carbon dioxide emissions, if electricity generation plants fired by fossil fuels were equipped with carbon capture and storage systems or replaced with renewable energy or nuclear-powered plants,” the study said.

Another National Research Council study, “Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use,” was released in November. It warned that producing electric cars—and their batteries, which are very energy-intensive to manufacture—would likely bring its own health and environmental impacts.

Paul Scott, vice president and co-founder of the group Plug In America, points out that electric cars already produce less carbon dioxide than gasoline cars and will only get greener as the country’s electric grid becomes greener.

The greening of the grid and the coming of electric cars may actually present a chicken-and-egg situation. Government studies have found that electric cars, if charged at night, wouldn’t require the construction of new power plants and could even encourage the development of variable renewable energy sources like wind by absorbing excess energy when it is available.

In the future, allowing cars to both take energy from the grid and give energy back—the “vehicle-to-grid” concept—could increase the overall efficiency of electricity production by reducing the need for spinning reserves.

One million plug-ins

The first step is getting the cars on the road.

Hybrids currently account for about 2 percent of all vehicle sales in the United States, while electric cars and plug-ins—most of them converted from stock vehicles—make up less than one tenth of one percent of cars on the road.

Those numbers are almost certain to grow, but for now, it’s unclear which new technology will prove the most successful.

Toyota, whose Prius is the best-selling hybrid in the United States, isn’t putting all its eggs in one basket. In addition to the plug-in hybrid, the company plans to introduce an electric car in 2012 and a hydrogen fuel-cell vehicle in 2015.

Company spokesman John Hanson said he doesn’t know what kind of market penetration is likely in the future. “It’s a big huge question mark,” he said.

“We think there’s a lot of opportunity with plug-in hybrids,” Hanson added, “but the market will decide.”

President Obama has stated a goal of putting 1 million plug-in hybrids on the road by 2015, but his administration is also betting heavily on electric vehicles. In August, Obama announced $2.4 billion in federal stimulus grants supporting the production of electric vehicles and a network of charging stations aimed at making them more practical.

One grant, worth $99.8 million, was awarded to the electric Transportation Engineering Corp. (eTec) for a three-year project to install more than 10,000 electric car charging stations in five states and deploy 4,700 Nissan LEAF electric cars. (Electric cars and plug-ins can be charged at home, but special charging stations will increase range and can speed up the charging process.)

The importance of batteries

Ultimately, the success of plug-in hybrids and electric vehicles will depend largely on battery technology. Batteries are important because they determine how far an electric car can go on a charge and how long it takes to recharge. A battery’s efficiency determines how big and heavy it is, and its cost affects how attractive electric cars are to consumers. (The Department of Energy’s Vehicle Technologies Program, working with car manufacturers, has identified cost, performance, lifespan and abuse tolerance as the main technical barriers relating to energy storage.)

Batteries are so important that $1.5 billion of the DOE’s $2.4 billion in grants went to companies that make batteries and parts for them. The government grants are meant to

jumpstart U.S. production of the high-tech batteries and allow the kind of mass production that could make them cheaper.

Hybrid vehicles currently rely on nickel-metal hydride batteries, while all-electric vehicles use lithium-ion batteries like those found in laptop computers. The two types of vehicles are fundamentally different in that hybrids generally sustain their batteries’ charges while electric cars and plug-ins deplete and recharge their batteries.

Toyota, for instance, hasn’t announced any plans for putting lithium-ion batteries in its regular hybrids, but does plan to use them in 2010 in a demonstration fleet of plug-in hybrid Priuses.

That said, some observers say the more powerful lithium-ion batteries will become the battery of choice for conventional hybrids as the batteries become cheaper. Ultracapacitors, another kind of energy storage device, are also considered a promising technology for electric vehicles.

Making better batteries

In addition to the $2.4 billion in grants to battery makers, the DOE is supporting research projects with the potential to revolutionize battery technology. The department’s Advanced Research Projects Agency-Energy, inspired by a similar program for defense technology, supports high-risk projects with the potential for high payoffs.

In October, the ARPA-E announced $151 million in funding for dozens of projects, including several that could improve batteries for electric vehicles.

One project, led by a spin-off company of Arizona State University called Fluidic Energy, involves using ionic liquids to make a metal-air battery the company says could provide 11 times the energy density of top lithium-ion batteries at a fraction of the cost.

Another project, by the Argonne National Laboratory’s Envia Systems, seeks to triple the energy density of lithium-ion batteries through the use of nano silicon-carbon composite anodes and manganese composite cathodes discovered at the lab.

A third project, by Inoranic Specialists, explores the possibility of using silicon-coated carbon nanofiber paper as the anode in lithium-ion batteries.

The ARPA-E also funded a project by a spin-off of the Massachusetts Institute of Technology involving ultracapacitors. The spin-off, FastCAP Systems, is seeking to develop ultracapacitors that are similar to batteries in their energy density but can provide more power in short bursts and withstand millions of charge-discharge cycles.

The ARPA-E is currently seeking proposals for another $100 million in grants, including those relating to electrical storage for transportation. In a news release announcing the grant money, DOE wrote that technologies developed under the program, if successful, would overcome the major hurdles to widespread deployment of electric vehicles.

“The development of high energy, low cost batteries represents the critical barrier to wide-spread deployment of EVs,” they wrote, “which if achieved would have a profound impact on U.S. oil security, greenhouse gas emissions, and economic growth.”

Links of interest

Hybrid electric vehicles

Plug-in hybrid vehicles

Electric vehicles

DOE’s Argonne National Laboratory model for well-to-wheel energy use and emissions for various types of vehicles

EPRI and NRDC study

Hidden Costs of Energy

Plug In America

The EV Project (with eTec)

List of stimulus grants for hybrid and electric vehicles

List of hybrid and electric vehicles

ARPA-E grants for new technology

ARPA-E Web site

Story on Fluidic Energy

Story on FastCAP Systems

FastCAP Systems Web site


Contact Stefan Milkowski at