May 21 - McClatchy-Tribune Regional News - Jim Downing The Sacramento Bee, Calif.

Move over, Prius, the plug-in hybrid is coming.

With a recent mandate that effectively requires major automakers to put at least 58,000 gas-electric vehicles on California roads by 2014, the state is prodding new technology forward.

After years in the prototype stage, auto industry giants and startup companies are investing, researching and building prototype vehicles that can be fueled either with gas or electricity from a wall socket.

General Motors and Toyota plan to launch versions by late 2010, while Honda and some smaller manufacturers are expected to follow.

"Plug-in hybrids are going to be the vehicle story of the next few years," said Joseph Romm, an energy policy expert with the Center for American Progress, a think tank in Washington, D.C.

Before they become as prevalent as a Prius, however, plug-ins must clear a few hurdles, mainly involving battery technology.

"The largest issues are battery cost, life and reliability," said Menahem Anderman, a Yuba County-based consultant who specializes in automotive battery technologies.

The 300-pound battery pack General Motors is building into its Chevrolet Volt plug-in, for instance, can't yet deliver its promised 40-mile range and the long-term durability needed for a mass-market car, according to a report by a hybrid technology research team at the University of California, Davis.

GM says the batteries are progressing, but many experts doubt they'll be road-ready in time for a scheduled 2010 launch.

The problem: Batteries tend to perform best, and last longest, when discharged gently. But ordinary driving -- accelerating up a freeway onramp, say -- demands big bursts of power. While a huge battery pack -- several times what GM wants -- can handle that load, smaller ones wear out quickly under the strain and have problems with overheating. Big battery packs also are more expensive.

That has battery manufacturers and entrepreneurs hustling to find a fix.

One of those is AFS Trinity, an energy technology company staffed primarily by former Lawrence Livermore Lab engineers who've developed the XH-150, a plug-in prototype.

Backed by $50 million in venture capital, AFS Trinity believes its patented design resolves some battery problems. The company claims it has created the only functioning plug-in hybrid with a 40-mile all-electric range.

AFS Trinity founder and CEO Ed Furia, an organizer of the first Earth Day in 1971 and former federal EPA administrator, is in Sacramento this week, meeting with state officials and showing off his prototypes -- a pair of modified Saturn Vue Green Line hybrids.

They're designed to get around the battery problem by using ultracapacitors -- a scaled-up version of the devices that allow a small camera battery to provide the burst of electricity needed to power a flash.

The car's instrument panel looks ordinary, save for two analog gauges on the dashboard. One shows the battery level, the other the capacitor charge.

While Furia's Vue is driving at a steady speed, the batteries charge up the capacitors. On a hard acceleration, the capacitor acts as a booster, giving the electric motor the juice it wants, and taking much of the load off the battery.

During a recent test drive, Furia pulled over to the shoulder of Interstate 5 just north of downtown to show how the capacitors work. What came next is clearly his favorite part of a test-drive.

"Anybody have any health problems?" he said, jokingly.

Then Furia stomped on the accelerator, and the car rocketed to 65 mph.

Conventional hybrids have a reputation for being gutless, yet Furia takes pride in his vehicle's power. "There's the perception that if you get an electric car, you give something up," he said.

Furia has filed a number of patents on the capacitor design and hopes to sell the idea to a major automaker. If mass produced, he estimates, the XH-150 would cost $8,700 more than the standard Saturn Vue Green Line.

Based on prototypes like the XH-150 now being tested on California roads, plug-ins promise to put the fuel economy of today's hybrids to shame.

Comparing dollars per mile, internal-combustion engines are not as efficient as electric motors. It costs around $1 for enough energy to drive the XH-150 40 miles on battery power. Since most drivers are on the road less than 40 miles most days, the potential savings are huge, especially with $4-a-gallon gas.

What's more, a vehicle running on electricity has no smog-forming tailpipe emissions, and, even when pollution from electricity generation is taken into account, emits less greenhouse gases than a similarly sized vehicle burning fossil fuel.

Dan Sperling, director of the Institute for Transportation Studies at UC Davis, said the next few years will likely see companies large and small producing different riffs on plug-in hybrids, seeking the combination of sticker price, electric range and overall fuel efficiency consumers want.

"The industry is going to be experimenting for many years trying to figure out how best to design the tech in a way that consumers will value it," Sperling said. "They have to figure out what people are really willing to pay a premium for."