Car assembly will never be the cleanest of processes, despite the efforts of people like Gordon Murray whose i-Stream production method for his T25 and T27 microcars is said to reduce the energy of car production by as much as 80 percent.

Still, some companies do make the effort to bring down the environmental impact of car production. Smart's "Smartville" production facility in Hambach, France is one of the world's cleanest car factories, taking up less space than many plants, and clad in panels made from the wood of a fast-growing tree, carrying the mantra of "reduce, re-use and recycle" wherever possible.

And now Ford are making steps towards cleaner production too. Their assembly plant in Wayne, Michigan is trialling new Balqon XE-20 zero-emissions yard tractors.

We're already familiar with the concept of electric fork-lift trucks, but Ford's yard tractors can be used to haul around much heavier objects on large trailers, pulling everything from chassis and tires to a few full size trucks. The factory produces vehicles like the Expedition and F-Series, and the trucks are well up to hauling them about.

Specifications? Motive power is provided by a 230 volt, 200 horsepower electric motor. The 124 kilowatt-hour battery provides a 50 mile range. Not much, you might think, until you realise that the range takes into consideration the 90,000 pound loads the truck can pull. You can thank the massive torque from the electric motor for that.

Ford are leasing the tractors through an agreement with the manufacturer and T&K Logistics. If you were thinking it's a pity the factory only makes gas-guzzlers, rest easy. The factory is being converted to make the next generation Focus, and that includes the full EV model.

Does an electric tractor make much difference to green production? It's hard to say at this point, but every little helps.

[Gas 2.0 via Reuters]