High Speed Trains like the Bullet Train in Japan, the Frech TGV or Germany's ICE don't produce any fumes when running, but they eat a ton of electricity. Because this power doesn't always come from the best renewable sources, some scientists at Tohoku University in Japan are trying to reduce the energy these machines need to run.
They have come up with an interesting idea: using ground effect to raise the train a few inches from the ground and hece reduce all losses of power from ground friction. The train becomes then a ground version of the USSR's ekranoplan which used the same principle over water.
So far, the prototype weighs 400 kg (about 900 pounds) but reaches 150 km/h (90 mph). The ground effect is produced when a vehicle, at certain speeds, creates a difference of pressure between the air that flows underneath and over the vehicle.
The scientists claim that energy use with this floating style is dramatically lower than maglev trains, where a lot of power is needed to maintain the magnetic fields that sustains the train.
What's even more interesting is that this prototype uses power from windmills and photovoltaic panels installed along the same track where it hovers to make it a sustainable transport method.