Porsche have already stunned their sports car fans during the past decade by offering diesel and hybrid versions of their Cayenne sports utility vehicle.

More recently, they've had success in racing with their 911 GT3 R Hybrid, which provides up to 160 extra horsepower via a Kinetic Energy Recovery System (KERS) to the front wheels, for short bursts of extra traction.

Now the German sports car company has confirmed they've begun trials on full electric vehicles, and testing has begun on three Boxster models with electric drivetrains.

The test cars will be used to provide data on new electric drive components and battery systems, and field tests will be carried out to look into the required EV infrastructure and the use their future electric cars might face. These tests will start next year.

The aim, according to Porsche, is to combine greater efficiency with lower fuel consumption and emissions. With an EV, of course, the ultimate goal is to reduce emissions to zero.

Porsche CEO Michael Macht has confirmed that Porsche will eventually offer an electric sports car, but only if the company feels it can "offer product qualities typical of a Porsche."

The new car would likely give Tesla a competitive rival for its 2011 Roadster 2.5, but we're not holding our breath just yet--at these early development stages, it could be a good few years until an electric Boxster hits the streets.

In the meantime, the closest you're likely to get to an electric Porsche is the 2011 Cayenne Hybrid SUV, powered by a 333-horsepower, 3.0 liter supercharged V6 with a 47-horsepower electric motor.

Its performance is hot, but the 20 miles you'll do to every gallon might leave you a little cold. Looks like you'll have to wait if you want a truly green Porsche ...

[Green Car Reports]