Volkswagen has introduced the Golf Twin Drive Concept, which takes a step toward a holy grail of sorts for the automotive industry: a diesel plug-in hybrid. Jalopnik reports that the concept car can be run in electric-only mode for a range of up to 30 miles using an electric motor that makes 82 hp. In addition, there's a 2.0 liter turbodiesel that makes 122 hp, which takes over once the batteries are run down.

The two engines in tandem combine to produce 174 hp. There's also a regenerative braking system and start-stop technology that temporarily powers off the whole shebang when sitting in traffic. According to the report, Volkswagen will work with the German government in experimenting with a fleet of 20 Twin Drive Golfs in 2010. The company also plans to generate the electricity necessary to recharge the things by use of green resources, including windmills and hydro-electric dams.