Ford Motor Co. Chairman and CEO Bill Ford’s remark at the company’s annual shareholders meeting last month that the auto maker was looking into ‘plug-in’ hybrid-electric vehicles (PHEVs) immediately led to industry speculation Ford was in the process of developing such technology.

“We are very keenly looking at it and working with that technology,” Bill Ford told his audience at the time.

However, a Ford spokesman says “a lot more development is needed to make (PHEV technology) commercially viable.”

Ford is not alone in its thinking.

PHEVs, like traditional hybrids, would recharge their batteries through onboard generators and friction energy recovered from braking.

However, they have the added benefit of having batteries that can be recharged by plugging them into a 120-volt household power outlet, greatly expanding the vehicle’s range in electric-only mode and saving additional fuel.

Although Ford officially declines to discuss future product plans, Sue Cischke, vice president-environmental and safety engineering, tells Ward’s there are obstacles to developing such technology.

“You read about how ideally (PHEVs) can work, but there are other issues such as added weight, the need for more battery capacity and how it works with the power grid,” she says.

“So, Mr. Ford is saying we’re looking into it. A lot of people are very much interested in (PHEV technology), and we have to confirm that it is the way to go. Everything is on the table.”

Toyota Motor Corp., considered one of the leaders in HEV technology, agrees there are inherent drawbacks to developing PHEVs.

“Plug-in HEVs won’t be commercially or technologically feasible to build until battery technology improves,” Dave Hermance, executive engineer-environmental engineering for Toyota Technical Center USA Inc., recently told Ward’s.

Currently, HEVs are equipped with nickel-metal-hydride battery packs, which supplement the power of the vehicle’s traditional internal combustion engine.

While PHEVs provide a larger electrical charge, today’s batteries are not designed for excessive use, unlike consumer electronic devices that can be fully charged and then fully discharged.

Hermance says plugging in HEV batteries causes them to “operate frequently at their minimum and maximum 20% of capacity, which is when most damage occurs.”

Felix Kramer, a former Silicon Valley entrepreneur, self-proclaimed PHEV guru and founder of CalCars.org – a non-profit group dedicated to making PHEVs a reality – disputes auto makers’ claims.

Kramer, whose Redwood City, CA-based group has modified several HEVs into PHEVs, says the technology is viable today, and past vehicles prove the argument of inadequate batteries is not true.

“The best example is the (Toyota) RAV4-EV in the late 1990s,” Kramer says of the now-defunct all-electric cross/utility vehicle. “They built those cars and sold them in California, which required the batteries to last 150,000 miles (241,402 km).

“Toyota said they would last 75,000 miles (120,701 km) and would have to be replaced halfway through the vehicle’s lifecycle. But today, there are some still on the road with no sign of degradation of the batteries.”

Kramer claims his group has approached Ford about forging a partnership to develop a demonstration fleet of plug-in Escape Hybrids. Correspondence is ongoing, he says, but nothing has been agreed upon at this point.

A Ford spokesman says he has “no knowledge of any correspondence,” with the group but doesn’t rule out the possibility, saying the auto maker receives “thousands of inquiries a year.”

In addition to pressure from environmentalists, some elected officials are calling on auto makers to develop PHEVs. On his website, U.S. Rep. Rahm Emanuel, D-IL, calls for the government to “provide credits toward the installation of hybrid plug-in conversion kits.”

And in February, during a stop at a Johnson Controls Inc. facility in Milwaukee, President Bush said, “using new lithium ion batteries, engineers will be able to design the next generation of hybrid vehicles, called plug-in hybrids, that can be recharged through a standard electrical outlet.”

Dave Szczupak, Ford group vice president of manufacturing-The Americas, says PHEVs have potential, but they’re not necessarily a means to an end to innovative powertrain technology.

“I think the idea of having the ability to charge the battery overnight to get even more available energy is maybe just another way to top things off,” he says. “It’s not the answer that we’re all going to have plug-ins. It’s just another level (of HEV technology).”

bpope@wardsauto.com