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Density, Ewan Pritchard explains, is the key factor in battery power. Compared with a tank of gasoline, which packs a lot of punch into a relatively small container, the standard lead-acid battery is a wimp, and the nickel-metal hydride battery—standard equipment in the Prius, for example—is only marginally stronger.
The challenge is to make a battery that's small enough to fit in a car but still supplies it with enough zip to go fast and enough energy to carry it for hundreds of miles. In that sense, lithium-ion batteries were a breakthrough compared to the nickel-metal hydride models, offering vast power potential that is as yet, however, only partially realized. But the labs in NCSU's FREEDM center are on the job in multiple ways, aided by major funding from the National Science Foundation, the U.S. Department of Energy, Toyota, General Motors, the utilities, Progress Energy and Duke Energy, among others.
Pritchard says N.C. State's newest batteries are testing at 4–10 times the density—and thus, the power—of the state-of-the-art batteries that Dick Dell markets and are in the ATEC car. That advance puts N.C. State labs at least even with the best in the country, he says, and probably at No. 1.
Research has dropped the cost of lithium-ion batteries by about half over the last four years. N.C. State's goal is to cut the cost by half again by 2014 while boosting density to the point that a battery the size of the one in the Prius would run for 200 miles on its own—for a cost of $5,000 or less.
In a lab that, interestingly, is part of NCSU's College of Textiles, Pritchard reveals one secret element of the density—and power—gains: nanofibers. The composition of the fibers, and the solutions used to prepare them, are closely held, and in fact, the lab is filled with containers of different solutions being tested on various fibers.
But the point, he says, is that enormous volumes of the tiny fibers can be baked and packed into a battery as conductors for electricity. Think of electricity running along the little threads instead of jumping across spaces between particles—the density is greater, and so is the power.
Is there any limit to the density that can be achieved? Pritchard pauses. Theoretically? No, he says.
Other NCSU labs are working on battery controller technology. Controllers "pulse" power from the battery to the engine. Another breakthrough technology developed on campus has improved their efficiency so that cooling—the radiator and water pump—may be unnecessary in electric vehicles.
Pritchard decided he wanted to work on electric cars as a teenager in Cary. He majored in mechanical engineering at NCSU, but by the time he graduated, EVs had taken a big hit in California. Despite the Golden State's efforts in the '90s to promote them as a "zero-emissions" technology, nobody wanted the low-power, low-range cars using then state-of-the-art nickel-metal hydride batteries.
It wasn't until hybrids came along, solving the range problem at least, that the outlook for EVs brightened again. With lithium-ion, it's shining brightly.
By 2020, Pritchard predicts, batteries should be capable of 500-600 miles on a charge, and high-volume production should further drop the price. At that point, gasoline will be on the run, unable to sustain sales even at $2 a gallon when electric sells for the equivalent price of 75 cents.
"The future is inevitably electric," he says. "The source of the electricity is up for debate. There may even be some kind of power plant within the vehicle," which would mean no plug-in needed. "But it's a foregone conclusion, the thing turning the wheels is going to be some form of electricity in the future."
Which raises the question of the impact of EVs on the electric industry. Looked at one way, it's insignificant: A study by the industry-funded Electric Power Research Institute (EPRI) determined that, even with 10 million electric vehicles on the road, the additional "load" on the grid—the extra electricity needed to run them—would be less than 1 percent.
From the standpoint of renewable energy, though, the impact could be huge. In another FREEDM center lab, Pritchard unveils a prototype of a two-way charging system—V2G, for short, meaning vehicle-to-grid.
If installed in a charging station like the ones Dell is selling and the utilities are beginning roll out, the V2G technology would allow the utilities to take power from cars as well as supply it.
In his book Carbon-Free and Nuclear-Free: A Roadmap for U.S. Energy Policy, Dr. Arjun Makhijani, president of the Maryland-based Institute for Energy and Environmental Research, calculates that 100 million cars—one-third of the U.S. fleet—equipped with 10-kwh batteries would have 100,000 megawatts of stored power, the equivalent of 100 large nuclear plants.
Makhijani is one of the scientists arguing that enough solar, wind and other renewable power sources can be captured in the United States to eliminate the need for coal plants and, eventually, nuclear plants.
Solar and wind are considered problematic by the utilities, though, due to their intermittency—the sun may not shine, the wind may not blow. A recent study by Dr. John Blackburn, an economist and former chancellor at Duke University, found that in North Carolina—his test case—the wind and sun are complementary sources: When the sun is down, the wind is up.
Combined, the two form a reasonably steady source of power, Blackburn argued, especially when backed up by a reliable standby power source, which car batteries could be.
Is that prospect a real one? "It is for real," Pritchard says. He points to yet another innovation in the FREEDM center, "intelligent nodes" for a smart-grid system to replace the current transformer technology.
Such nodes could function like a stock exchange for the grid, smoothly managing the transfer of power from transmission lines to households and from households—with their solar roof panels and their idle car batteries—back to the lines.
One reason the utilities resist receiving power from many sources, Pritchard says, is their fear of millions of random power surges adding up to a big problem of "harmonic distortion" capable of crashing the system.
Intelligent nodes could eliminate such surges almost entirely, allowing a simple "plug-and-play" system in which any household could sell to the grid as easily as buying from it.
Right now, Pritchard says, the utilities are mainly interested in selling—that is, in charging cars, especially at night when surplus power is available from their plants. EVs charging overnight would make the electric system run more smoothly, which appeals to the utilities, he adds.
On the other hand, the utilities don't want people charging cars during the day, particularly on hot days when the air conditioners are running and the grid is stressed. That's when Progress and Duke could be interested in taking some power from parked cars via the V2G chargers—not all of it, but some fraction that the car's owner, probably using a smart phone, has told the smart grid she's willing to sell.
So let's say you own an EV with a 10-kwh battery. Its range is 200 miles. You drive it five miles to work. It's parked all day in your company's parking deck, plugged into a V2G charging system. If Progress Energy needs it, you've sent the message that you're willing to sell back half of your battery's stored power.
So have millions of other EV owners.
"Is the plug-in vehicle the 'killer app' for the smart grid?" Duke Energy's Mike Rowand, the utility's director of advanced customer technology, asked an audience at an NCSU-sponsored transportation and energy conference in May.
He didn't answer the question. But others did, and their answer was, of course.
Mike Waters, Progress Energy's advanced transportation manager, says his company is committed, as is Duke Energy, to helping electric vehicles come to the market. Both companies have growing fleets of EVs of their own, including the first bucket-truck models. Both are establishing several hundred charging stations, primarily in the Triangle and the Charlotte area.
And both see the advantages to the environment, to consumers and to their own operations, from vehicles that cost less to run, don't foul the air with their emissions, and—if charged during off-peak hours—help the utilities use their coal-fired and nuclear plants more efficiently.
"Clearly we support the technology, because it's a win for everybody," Waters says.
But Progress Energy also believes, he adds, that its grid technology "will be fine for a long, long time in terms of vehicle adoption" without any need to push to vehicle-to-grid systems, which some call Smart Grid 2.0. Nationwide, the basic system could cost $100 billion, but it could also cut electric transmission costs by that amount annually, says U.S. Energy Secretary Steven Chu.
Car-battery storage as standby power is "interesting" and has great possibilities, Waters says, but it will be many years before enough EVs are on the road to justify the expense of a large-scale Smart Grid 2.0 installation.
"If you had enough vehicles out there, where it really became a large enough load source, then absolutely, I think that's an interesting idea to see that as a virtual peak power plant," he says.
For now, however, both utilities are content with basic grid improvements, which will help them to deliver more power on existing transmission lines or on smaller new ones but do little to help others transmit power to them.
Nor is the N.C. Utilities Commission pushing the utilities on smart-grid issues. The commission recently showed some interest in the subject by opening a smart-grid docket—a means of taking testimony. But the major initiative thus far, according to James McLawhorn, who heads the electric division of the commission's public staff, is to call on the utilities to make annual reports about their smart-grid progress.
Duke Energy and Progress Energy, says John Runkle, a utilities expert who is general counsel to NC WARN, "have dragged their feet for years" on the subject of net metering—which would require the utilities to pay as much for the electricity they buy (from solar, wind and other generators) as they charge for selling it.
The term refers to having electric meters run forward, as usual, when a customer is taking power from the grid, and backward when she's sending it. "It's not to their advantage to do net metering," Runkle says. "They like to sell energy. They're not anxious the other way."
That dynamic won't change, says Ivan Urlaub, executive director of the N.C. Sustainable Energy Association, until state policies change to give the utility companies an incentive to welcome outside power. As it stands, any power the utilities buy cuts into their profits.
In 2011, the association expects to lobby the General Assembly for policies that require the utilities to accept more outside power and reward them for doing so. Solar and wind, and the companies that generate them, would be the main beneficiaries. But in the not too distant future, thousands of EV owners, or tens of thousands, or hundreds of thousands, may be calling their legislators saying, we'd like to sell some power, too.
And that might change everything.
Innovative developments in battery technology and carbon nanofibers at North Carolina State University are bringing us closer to a more viable and powerful electric automobile. Ewan Pritchard, program director of the Advanced Energy Transportation Center, narrates this entertaining look into battery technology and the production of carbon nanofibers inside the College of Textiles.