Despite being one of the great green hopes for the future, electric cars still have a long road to travel before they can hope to replace their internally-combusted brethren.

To illustrate this, AFP is today reporting that agreement has been reached on a ‘common plug’ for recharging the vehicles. In a few years drivers may find themselves pulling into filling stations and saying, “Fill her up with 400-volt three-pin premium.”

That’s right; despite multiple cars being available or in development and some governments already considering thousand pound subsidies of the vehicles it has only just been decided how drivers will actually juice them up.

According to AFP, who are themselves referencing German paper Die Welt, the German energy company RWE has announced an agreement between car makers including Volkswagen, BMW, Ford, General Motors, Fiat, Toyota and Mitsubishi and energy companies including Eon, Vattenfall, EDF, Npower, Endesa and Enel.

This has settled on a three-point, 400-volt plug that will be unveiled today (Monday) at a technology fair in Hanover, says the newswire.

It’s not entirely clear how this fits with General Motors’ announcement last week of its own SAE J1772 standard for recharging cars such as the forthcoming Chevy Volt. “You’re already aware we’re working to make the Volt as efficient as possible, but we’re also helping lead the standardization of this plug and how you interact with it as well as the electrical grid,” said Gery Kissel, a GM energy storage systems engineering specialist, on the company’s Fast Lane blog.

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