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Toyota Mirai: Toyota's Second Pioneer

During the “Zero Emission Tour,” Toyota invited attendees to the Mainz Energy Park, one of the largest hydrogen production facilities in Europe, and revealed some background information on the fuel cell topic.

In the Mainz Energy Park, Toyota provided an insight into the production of hydrogen. | Photo: G. Soller
In the Mainz Energy Park, Toyota provided an insight into the production of hydrogen. | Photo: G. Soller
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In the meantime, the Mirai has been produced about 10,000 times, and as if Toyota Germany had foreseen it, a workshop on the topic of fuel cells was set up, which was rich in content: Because as easy as the Mirai is to drive, the overall system with fuel cell technology and hydrogen production is just as complex.

The first is extremely elaborate and is still largely done by hand, and the latter cannot really be represented without efficiency losses and truly green. Nevertheless, the topic has a future, albeit primarily in heavy vehicles where payload and unladen weights are concerned. Even here, the Mirai already has advantages: According to product manager Widger Falk, its complete drive system with tanks weighs around 250 kilograms, which is less than a combustion drive system. The car cannot explode or burn, as it is actually equipped with relevant sensors at critical points that shut down the Mirai at a hydrogen concentration of 1.6 percent (explosive would be four percent). Additionally, Toyota has conducted destruction tests by setting it on fire: The combustion engine eventually caught fire and burned out completely, while in the fuel cell test vehicle, a hydrogen flame shot out of the tank, and it was quiet. Also, the tanks, which Toyota manufactures itself using a special weaving technique with carbon and glass fiber that harks back to the company's origins in weaving looms, were shot at with caliber 50 – the tank held! After all, it has to withstand temperature differences of up to 100 degrees when refueling! Refueling takes place at minus 40 degrees, and the end temperature can reach up to plus 60 degrees. A Mirai in Germany has also survived a severe rear-end collision: The rear end no longer existed, according to Falk, but the tanks remained intact.

So, checkmark – the Mirai drives with a consumption of 0.9 to 1.1 kilograms per 100 kilometers depending on the driving style, and it is as unobtrusive as its appearance is unusual. And: Toyota is already planning the successor, which is expected to come to Germany in 2021 – again as a sedan under the name Mirai, but then in higher quantities: Instead of 3,000 units, 30,000 units per year are to be built! This means that six-figure numbers are to be expected over the lifecycle.

The production of hydrogen remains difficult, as seen by a "large" pilot plant in Mainz, which is operated jointly by the local utility company and Linde. Here, there's already a 30 percent efficiency loss just to split the heavily purified water. If the hydrogen is then filled into trailers and transported to the filling station using diesel, the fuel's efficiency drops even further. Additionally, the heavy tank trailer has to transport a large volume but only about 350 kilograms of payload! This could be handled by a cargo bike if necessary. The situation with green electricity for hydrogen production is also complex: although the Mainz plant is backed by four wind turbines, their electricity is first fed directly into the grid due to the current EEG surcharge. Instead, the three "Silyzer" electrolysis units from Siemens and the ionic compressor from Linde purchase electricity, ideally when it is extremely cheap or even when the Mainz-Wiesbaden utility company, which manages the electricity purchase, receives money for the load. This way, around 200 tons of hydrogen can be produced annually, and part of it is also fed into the natural gas network, supplying 3,000 households with a natural gas-hydrogen mixture. Nevertheless, the plant is still more of a giant pilot project than a real "large refinery." Despite this, it is one of the largest electrolysis centers worldwide!

To truly get it “green,” according to Linde plant engineer Martin Neuberger, exclusively (more expensive) green electricity would have to be used, and transportation eliminated. Ideally, this means the hydrogen filling station would be located directly next to the production plant, which in turn receives its electricity directly from alternative energy sources. Additionally, by-products such as pure oxygen and a lot of waste heat are generated, which still need to be reused. For example, through a district heating network. Therefore, hydrogen should rather be generated decentrally in a demand-appropriate and, above all, green manner because only then will its overall energy balance become better. 

But this is where the interest increases: Railway lines and bus depots are candidates for such production, and municipalities are currently also the drivers of demand, which is also rising here. Mirai Key Account Manager Frank Still always observes the same phenomenon: When a hydrogen filling station opens, it usually leads to an order – especially since Toyota can deliver the Mirai within five to six months. And yes, demand is rising – albeit on an extremely low level: 230 units have been sold in Germany so far, making the Federal Republic the third largest Mirai market after Japan and California. And what about reliability? Still just smiles. The first vehicles have now run 160,000 to 170,000 kilometers at Clever-Shuttle – without problems, and with glazed rather than worn brake pads. As mentioned, the car works – now in 10,000 units. But producing hydrogen proves to be more difficult in detail than expected!

What does this mean?

For the automotive industry, the problem of producing fuel cell vehicles may be less significant than for the energy or hydrogen producers. But when the topic spreads to commercial vehicles and rail, demand for the substance derived from water will also increase.

Translated automatically from German.
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