As far as buses are concerned, will hydrogen or electric win?


Find new ways For a long time, powering global vehicles has been an important part of the response to the climate crisis. For small passenger cars, there is no doubt that the future depends on pure electric vehicles, not cars powered by hydrogen fuel cells-another viable alternative. However, as the size of vehicles increases, hydrogen may become an increasingly attractive option. For buses, some people believe that hydrogen power has several key advantages over battery electric vehicles. Which one of these eventually becomes the main technology of the bus may also have an impact on other modes of transportation.

Battery electric vehicles and hydrogen fuel cell vehicles have similar propulsion systems. Both store energy to drive the electric motor. However, in the latter, the energy stored in the form of hydrogen is converted to electrical energy by the fuel cell instead of being stored in a rechargeable battery.

Electric car sales Reach 3 million in 2020, An increase of 40% over 2019, and there are currently about 10 million electric vehicles on the roads of the world.The registration volume of hydrogen vehicles is still three orders of magnitude lower than this, and there are Only 26,000 On the global road, it is concentrated in three countries: South Korea, the United States (mainly California) and Japan. Although there are still several hydrogen fuel cell vehicles on the market made by companies such as Toyota and Hyundai, they are often more expensive than pure electric vehicles and are currently difficult to refuel: the purchase cost of hydrogen is high, and gas stations far away are more expensive than charging Less stations.

But when it comes to larger vehicles, the situation is less clear. As vehicles become larger, it becomes more difficult to electrify them, requiring larger and larger batteries. For energy-intensive applications, such as long-distance trucks, Some experts say Hydrogen may be the best choice.

In this range, buses are between cars and trucks. “The biggest issue is the quality of buses,” said James Dixon, a researcher in energy and transportation system modeling at Oxford University. “The energy density of a battery is relatively small: the energy density is about 1/40 of the energy density of liquid hydrocarbon fuels such as gasoline or diesel.” He added that hydrogen also has a relatively low energy density (per unit volume or area can be Stored energy)-about four to five times lower than petroleum fuels, but much higher than batteries.

China already has About 5,300 hydrogen fuel cells Buses on its roads account for the vast majority of the global fleet, but other countries are also investing in the technology. Neil Collins, managing director of Wrightbus, a bus manufacturer based in Northern Ireland, said his company has nothing to do with technology and is making battery-electric and hydrogen fuel cell buses. It inputs journey data from bus operator customers into a tool to model the different driving cycles of their vehicles to help them find the best technical solution for a specific route.

The advantages of hydrogen include a shorter refueling time and a larger tank range. Collins said, but hydrogen technology and infrastructure are more expensive, and the industry’s skills in using electric buses may also be higher than hydrogen. Dixon also pointed out that one of the concerns about hydrogen has always been its safety. “It has quite a wide range of flammability limits, and it is well known that it is difficult to store it in a pressurized container without leaking,” he said. “In terms of infrastructure, electricity is much easier because you don’t need liquid fuel trucks to drive around.”


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