Opel is planning to launch a series of electric-powered cars under Chevrolet Volt program. The recently announced $1 billion investment will include the development of various electric-powered vehicles based on the E-Flex architecture.

First up will be the production version of last year’s Flextreme Concept that is expected to arrive in the European market one year after the Chevy Volt, in 2011.

The Flextreme combines an electric propulsion motor and a 1.3-liter CDTI diesel. The diesel engine is onboard solely to power the generator and charge the battery.

The Flextreme can be charged in around three hours via a standard 220 V electrical socket. A fully charged lithium-ion battery gives the concept car a range of around 55 km or 35 miles in purely electric operating mode. When the battery is run down and no electrical socket available, the Flextreme’s common-rail diesel engine kicks in to provide electricity and recharge it.