We don't hear much about the 2011 Chevrolet Volt's half-brother, the Opel/Vauxhall Ampera, here in the States.

But in the U.K., the president of GM Europe laid out that group's plans for future generations of Ampera--and they're significant for what they say about upcoming models in an expanding lineup of Volt vehicles.

Three new vehicles in 2015

Within five years, according to Nick Reilly, a group of three range-extended electric vehicles using the Voltec powertrain will replace the single five-door Ampera model, which goes on sale next year in several European countries. (The Ampera has lagged behind the Volt by several months.)

opel ampera geneva live 004

opel ampera geneva live 004

The current plan, he told Autocar, is for the Ampera (and by extension the Volt) to be built at the Detroit-Hamtramck plant from 2011 through 2014.

The following year, a second-generation vehicle will be launched--and it could be built in multiple factories around the world, including one in Europe.

Hatch, sedan, crossover

The next Volt/Ampera will actually be a family of electric vehicles with range-extending gasoline (or diesel) engines, including a compact hatchback that effectively replaces the existing five-door model. 

There will also be a four-door sedan (which might find favor in North American markets, where sedans heavily outsell hatchbacks), plus a five-seat crossover that's likely to be similar to the Volt MPV5 concept from this year's Beijing Motor Show.

2011 Chevrolet Volt MPV5 concept, Unveiled at 2010 Beijing Motor Show

2011 Chevrolet Volt MPV5 concept, Unveiled at 2010 Beijing Motor Show

Higher range, lower cost

Reilly said the next generation of Volt products will offer better electric range, and the cost of its electric components will be as much as 50 percent lower.

The U.S. EPA rates the 2011 Chevy Volt at 35 miles of electric range; Chevrolet says the range is 25 to 50 miles depending on factors including speed, temperature, and use of accessories.

In the U.S., the 2011 Volt has a base price of $41,000 before Federal and local incentives, though it can also be leased for $350 per month.The U.K. price, by comparison, is around $58,000 (£37,000), though all vehicles cost more in European markets than they do in the States.

To make the Volt a mass-market vehicle, that cost must obviously fall substantially as incentives wane over time. Reilly said that the next generation of Voltec vehicles would cost approximately $8,000 to $12,000 (£5000 to £8000) more than the best-equipped model in a comparable gasoline-engined range.

First 2011 Chevrolet Volt built on production tooling at Detroit Hamtramck plant, March 31, 2010

First 2011 Chevrolet Volt built on production tooling at Detroit Hamtramck plant, March 31, 2010

Low production in early years

Like all vehicles with new technology, production volumes for the Volt and Ampera will ramp up only gradually as the costs of the cars' specialized components come down.Those include large-capacity lithium-ion battery packs, powerful electric drive motors, and the power electronics that convert among different voltages in the vehicle.

Toyota has sold more than 2 million of its hybrid-electric vehicles, for instance, and can build now more than half a million per year. But production of the first-generation Toyota Prius was only in the tens of thousands for several years after launch.

GM says it plans to build 10,000 Volts during 2011, and up to 45,000 in 2012.