Volvo Car Corp. says it will launch a plug-in hybrid car within the next three years.

Volvo and Swedish energy-company Vattenfall AB are taking their 2007 joint venture to develop plug-in technology to a new level, with the auto maker announcing it will release the electrified V70 sedan in 2012.

Volvo says in a statement it will field-test three V70 demonstration plug-ins this summer that will be used to gather feedback on what drivers want from the new technology, determine their driving habits and establish how they want to recharge their cars.

Vattenfall will test various concepts for high-speed home charging and also for charging stations in public places.

Volvo says the final plug-in car will feature somewhat different technology, but the launch of the demonstration vehicles is a step toward series-production of PHEVs specifically tailored to market needs.

The auto maker now is launching an industrial partnership with Vattenfall to introduce the hybrids.

"We are investing in an industrial JV to series-produce plug-in hybrid cars in Sweden in 2012, cars that can be powered by both electricity and diesel,” Volvo President and CEO Stephen Odell says.

“This is an important business development for us, and our partnership with Vattenfall allows us to take a giant step toward offering our customers cars with an even smaller environmental footprint.”

Vattenfall President and CEO Lars Josefsson says his company wants to reinforce electricity's importance in society and its key role in solving climate issues.

“Through this cooperation, we hope to be able to speed up the introduction of electric cars,” he says. “Together, we are developing the next-generation technology based on plug-in cars and various charging alternatives.”

Volvo will manufacture the cars, and Vattenfall will develop charging systems and supply the cars with electricity.

The partners say in the statement they believe series production of PHEVs and the development of infrastructure can generate new jobs and help Sweden maintain its position at the cutting edge of advanced pro-environmental technology.

The two say the purchase price of the plug-in hybrids will be higher than that of cars with conventional technology, but with the car running on electricity its fuel costs will be cut to roughly one-third compared with diesel power.

Vattenfall says it will offer hybrid owners the opportunity to sign an agreement for electricity from wind power or hydropower, as an alternative to the regular mix of electricity sources.

Josefsson says he sees many benefits from chargeable plug-in hybrids, even in cases where the electricity does not come from renewable-energy sources.

"Through electric power, we avoid the emissions from each individual car,” he says. “Instead of (gasoline) or diesel, the energy is derived from a few large power sources, and Vattenfall is working hard to eliminate carbon-dioxide emissions from all electricity production. In Sweden, virtually all Vattenfall's electricity production is emissions-free.”

The plug-in hybrid cars will be driven by an electric motor powered by a lithium-ion battery, which will take about five hours to charge from a standard wall socket.

"Most car journeys are short trips, for instance to and from work,” Odell says. “We will be able to offer a product that fulfills this transportation need. To cover longer distances, as well, the car also will be equipped with one of Volvo's fuel-efficient diesel engines.”