Is the Toyota Prius going hydrogen?

This is Toyota's Fuel Cell Vehicle, an eco-saloon set to be unveiled at the Tokyo show later this month. It previews a potential successor to the Prius, but rather than a petrol-electric hybrid powertrain, this concept is powered by hydrogen. And air.

The FCV is, as its name implies, a fuel-cell vehicle to rival the Honda FCX Clarity; the car, don't forget, that James May declared to be the most important car to come along for 100 years.

This isn't mere concept fodder either, with Toyota claiming the FCV is headed for production sometime around 2015. How does it work? Well, it's powered by electricity generated through the reaction between the hydrogen onboard and air from, erm, outside. This drives an electric motor to move the car forward, with water the only emission.

There's a compact fuel cell stack and a pair of high pressure hydrogen tanks on board. Toyota tells us it has a power output density of 4bhp per litre; more than twice the output of the company's previous fuel cell stack used in the FCHV-adv concept.

All in, we're promised a driving range of at least 300 miles, and a refueling time - at a designated hydrogen station, obviously - of just three minutes. Size-wise, it's on the same wheelbase as a Prius+, though is slightly wider and a bit longer.

No word on potential price, but the lack of a refueling infrastructure could see the FCV cost a little more than even the £33k plug-in hybrid Prius. We'll wait and see...

Alongside this future hydrogen motor, Toyota is also showcasing a few other concepts, including the JPN Taxi Concept (it's an LPG hybrid designed to be a Japanese minicab), the Voxy and Noah concepts (seven-seat MPVs for the Japanese domestic market) and the rather delightful FV2. It's Toyota's Segway, and incorporates voice and image recognition to determine the driver's mood, a driving history to suggest destinations (steady), and even provides information on better driving habits to make you a better human.

Back in the real(ish) world, is Toyota heading the right way with hydrogen, or is the future all-electric? Or diesel? Or...