General Motors has revealed its E-Flex electric Chevy Volt concept at the Shanghai Auto Show this week.

The Volt is the second incarnation to include GM’s E-Flex technology and was built by the US manufacturer as the ‘emphasis on reducing oil dependency continues to grow’.

Designed to support a range of alternative-fuel and alternative-propulsion engines, the Volt also previews what the next-generation Astra might look like.

The new concept uses GM's fifth-generation fuel cell propulsion technology and a lithium-ion battery to provide up to 300 miles of petroleum- and emissions-free electric driving. The E-Flex system can also operate on both hydrogen fuel cell-generated and grid electricity, and can drive up to 20 additional miles each time it is charged.

"The beauty of our E-Flex strategy is that it allows us to package various propulsion systems into the same space depending on what energy is available locally," said Larry Burns, GM's vice president of research, development and strategic planning.

"It also provides flexibility in the sources of energy. We can obtain hydrogen or electricity from a different renewable sources - wind, solar, geothermal, hydroelectric and biofuels - or from traditional sources such as natural gas, clean coal, nuclear or even gasoline.

"E-Flex provides flexibility in two ways: in the propulsion systems that can be used, and in the sources of energy that can be commercialized," added Burns.

GM will also unveil a biodiesel concept at the Frankfurt Motor Show in September, badged as an Opel.