Not the first to bring a FCV (Fuel Cell Vehicle) for commercial sale, but definitely the most influential. Toyota brings the Mirai, a FCV concept that was first showcased in 2013 as the Furia to consumers in Japan and the US of A. The Furia concept was initally showcased by publications as the new Corolla. However the release of the new Corolla in 2014 indicated that the changes were not that dramatic as believed earlier. What Toyota have done instead, is taken the practicality of the same platform, and made a Fuel Cell Vehicle, that puts out only water vapor as exhaust. The vehicle is dimensionally similar to the Toyota Corolla, but the similarities end about there. This is a pure Fuel cell vehicle, i.e. one that uses Hydrogen as fuel, and an electricity generator to produce electrical energy for the motor that drives the front wheels. The electric motor is rated at 153 HP and produces 334 Nm of torque. A hallmark of electric motors is that the torque is instantly available, and is uniform throughout. No gears are needed to increase or decrease the force being transferred to the wheels. Sure, you can increase the turning force by gearing, but 334 Nm is more than sufficient for a vehicle that weighs 1850 kgs roughly. Acceleration is claimed to be 9 seconds for 0-100 kmph dash, well within the market segment for such cars. Importantly, it has a range of 500+ kms (312 miles) on a single tank of (rather two tank) of Hydrogen. The Hydrogen is stored under extremely high pressure (10,000 psi + ) and there are two tanks under the rear seats that are used for storage. The tanks are made in a 3 layer structure with various composite materials. The inner layer is a polymer lined layer, inert to hydrogen, to store or contain the gas. This is re-inforced with a carbon-fiber polymer layer. The outer most layer is a glass reinforced polymer to protect it from surface scratches etc. All of this is contained outside the passenger compartment, so that in the event of any leak, the gas is dissipated outside the passenger area. There is a safety valve that shuts off the Hydrogen supply in the event of an accident. Moreover this vehicle has been tested extensively for collisions/roll-over accidents etc. Toyota have performed (in their pitch) over 10,00,000 miles of testing on these tanks/FCVs. My understanding is, CNG - Lighter than Air, LPG - heavier than Air, Hydrogen - Even lighter than air. Flammable, yes, all three. However, the hydrogen should escape quickly to the environment in the event of a tank rupture or leak. And at about 5 kgs of Hydrogen, though it is a lot, if we've allowed CNG and LPG to be used, this is as safe as any other gaseous fuel. The Mirai is an important proof of concept, that Hydrogen fueled vehicles are a possibility. However the debate still rages on whether Hydrogen vehicles are energy efficient or non polluting in the complete sense. This is one of the inherent issues that I hold against electric vehicles and hybrids. What about the pollution done in building the battery packs? What happens when the batteries die and need to be replaced? How much is re-cycled? Where is the electricity to charge the EV coming from? If it's coming from a thermal power plant, we're just moving the source of pollution from the road to an industrial unit. How much of the energy being spent in producing this electrical energy, is being used eventually? Quite a small fraction. A similar case exists for Hydrogen vehicles. If the process for extracting Hydrogen gas is not made efficient, a FVC uses only about 25% of the total energy spent on producing the Hydrogen gas. This is pretty wasteful when compared to a hydrocarbon powered engine. What is noteworthy is that the fuel cell technology has been downsized to a regular family sedan. A sedan that will cost about 58,000$ before tax exemptions and other rebates due to the environment friendly nature of the vehicle. The Mirai runs in a Battery power - Fuel cell power hybrid mode that allows it to exclusively use one power source, or the best of both when needed. For instance, if the battery pack is fully charged, or for normal ambling around, the vehicle relies exclusively on the battery for propulsion power. This is supplemented by regenerative braking, when used. To supplement this power, or under heavy acceleration or high speed cruising, the fuel cell can provide additional power by the breakdown of Hydrogen and combination with oxygen from the air, produces H20 or water. This water is collected in a storage tank, and at the press of a button, can be dumped from the car (no kidding). Water production is about 60 ml per km of running. The battery pack is a 1.6 KW-h Ni-Mh, taken from the Toyota Camry Hybrid. The electric motor is one that is used in a Lexus Hybrid model. This has also allowed them to keep production cost in check. The tanks weigh about 90 kgs. This is similar to a CNG tank in our Indian cars. All in all, I feel this is a step in the right direction. Though we need to figure out an easy way to extract/produce hydrogen gas, for this to be a complete success.