Toyota Mirai

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This is a different version of an electric car, which instead of relying on batteries that are charged up before use, then must power that car until the next time it is charged up, generates its own electricity whilst on the move, using fuel cells, to run an electric motor, and also power a battery.

豐田Mirai

Fuel cells work by producing a chemical reaction between hydrogen and oxygen which forms water and in the process generates the electricity that powers the car. Instead of harmful gases and particles, all the car exhaust emits is water vapour. Fuel cells were invented in 1938, and have been used in space exploration to generate electricity since 1960. The motivation to use fuel cells in cars is to reduce air pollution and also to provide an alternative to depleting oil supplies.

The car itself, launched in December 2014, is about the size of a Camry, and has purposely been given rather stand out styling to declare itself as different, and is also very streamlined (Mirai is Japanese for future). It is very spacious inside, and has all of Toyota's electronics and driving aids. The big front grills are to both cool the motor and provide air for fuel cell oxygen use. Dimensions in mm are L 4890, W 1815, H 1535, WB 2780, similar to Camry, and kerb weight 1850 kg, about 400 more than Camry. It is front engine, front wheel drive.

Electric traction motors don't need gears, and have full torque available from start through to top speed, meaning very good acceleration and pulling power, and no loss of speed through having to change gears. The Mirai develops 113Kw of power and a very high 335Nm of torque, and range of about 550 km.

Toyota utilised its long experience with electric hybrid cars to provide tried and tested components for the Mirai, using an electric motor from a Lexus hybrid, a Prius power control unit, a hybrid nickel metal hydride battery then drove prototype cars millions of kms in testing, including more than 16,000 kms in extreme climate testing.

The car's hydrogen supply is stored in two tanks, at 700 atmospheres pressure, and so to ensure maximum possible safety, the whole car has been greatly strengthened and designed to be highly crash resistant, with the fuel tanks carbon fibre encased and high strength polymer lined with five times the crash energy absorption of steel.

The car's 1.6 kW battery is regeneratively charged from braking, and also from the fuel cells, and works with the fuel cells co-operatively to power the car.

At present, the cars are sold in the US, Japan and Europe, about 1,500 altogether so far, being popular with early adopters keen to advance the cause of electric cars, even if expensive at this early stage, without economies of large production numbers, and subsidised both by government, and also Toyota itself, which loses money on every car sold at this stage!

A network of fuelling stations is being expanded continually in California, about 14 already around Las Vegas and Santa Ana, with about 1,000 cars sold.

In Japan the government is very eager to encourage the use of fuel cells, and has built about 80 refuelling stations so far, with plans to greatly increase the number, and has big plans for fuel cell powered car adoption. The use of fuel cells in homes is also greatly being promoted, reportedly with the installation already of about 150,000 units to date.

Toyota has brought 3 cars and a purpose built refueller to use in Australia until 2020, to demonstrate and popularise their cause, and is demonstrating and talking to government and businesses about them. At first, until fuel station networks are established, Toyota says a fleet of fuel cell cars could be refuelled at business or government base locations each day.

The fuel stations compress hydrogen before then refilling cars, and the hydrogen supply can be obtained from many sources in many possible ways, being the most common element in the world, but an ideal, low pollution way would be to use solar or wind power, and sewerage can even be used as the base material.

An advantage of using fuel cells instead of plug-in recharged batteries to power electric cars is that they only take about as long as petrol cars to fill up, whereas batteries take hours to recharge. Time will tell which becomes most popular!, and also whether fuel cell powered cars are going to live up to their promise and the expectations of those developing them and trying to bring them to successful wide scale commercial adoption.