How economical is it to operate even heavy-duty trucks with a 40-ton payload over long distances using purely battery electric power? The engineers from Stuttgart have a very clear answer to this rhetorical question – and they give seven reasons. The answer is of course: No, a battery drive is not economical for heavy-duty traffic over long distances. If only because of the battery weight, long charging times, and limited ranges, the electric drive with current battery technology is not the first choice for heavy commercial vehicles, according to the Bosch experts. As an alternative, they cite the fuel cell drive, which the company plans to bring into series production by around 2022 / 2023. With regeneratively produced hydrogen – i.e. hydrogen generated with electricity from renewable sources – a climate-neutral transport of goods and commodities is possible. Initially for commercial vehicles, but as technological maturity progresses also for passenger cars, the experts are convinced of this.
According to Bosch engineers, there are seven important reasons for the fuel cell:
Climate neutrality: Hydrogen is produced by electrolysis with a high input of electrical energy. If this energy is obtained from regenerative sources such as wind and solar power, the fuel cell drive is completely climate-neutral. a CO2 balance is better, especially for large, heavy vehicles, than for purely battery electric drives, if the CO2 emissions for production, operation and disposal are added together. In addition to the hydrogen tank, a much smaller battery is sufficient in fuel cell vehicles as an intermediate buffer/storage tank. This significantly reduces the CO2 footprint created during production.
Application versatility: Hydrogen has a high energy density. One kilogram of hydrogen contains as much energy as 3.3 liters of diesel. For 100 kilometers, a good seven kilograms is sufficient for a 40-ton truck. If the tank is empty, H2 can be filled up in a few minutes, as with a combustion engine; hours of charging cycles as with a battery electric drive are unnecessary. In order to achieve the Parisian climate protection goals, Bosch believes that hydrogen should in future power not only cars and commercial vehicles, but also trains, aircraft and ships.
Efficiency: The efficiency of a drive system is crucial for its climate-friendliness and economy. This is around 25 percentage points higher for fuel cell vehicles than for vehicles with combustion engines. The possibility of recovering braking energy further increases efficiency. Battery electric drives do indeed work even more effectively. However, since energy generation and energy demand do not always coincide in time and space, electricity from wind and solar power plants often remains unused because it cannot (yet) be stored. This is where hydrogen scores. With the surplus electricity, it can be generated decentrally, stored flexibly and transported.
Costs: With the development of larger production capacities and falling prices for renewable electricity, the costs of producing green hydrogen will drop significantly. The Hydrogen Council, an association of over 90 international companies, expects the costs of many hydrogen applications to be halved in the next ten years. Bosch is currently developing the stack, the heart of the fuel cell, to market maturity together with the Powercell start-up and will then manufacture it in series. The goal is a high-performance solution that can be manufactured cost-effectively. In the medium term, the company promises that using a vehicle with a fuel cell will not be more expensive than with a conventional drive.
Infrastructure: There is currently no comprehensive network of hydrogen filling stations; just 180 hydrogen filling stations are spread throughout Europe. In order to push ahead with the expansion, companies in many countries are cooperating, often supported by government subsidies. The H2 Mobility joint venture, for example, will have built around 100 freely accessible filling stations in Germany by the end of 2020, and the EU-funded H2Haul project will not only build the trucks, but also the filling stations required on the planned routes. There are also funding programs in Japan, China and Korea.
Safety: The use of gaseous hydrogen in vehicles is no more dangerous than other car fuels or batteries, Bosch argues. Hydrogen tanks do not pose an increased risk of explosion. It is true that H2 burns in combination with oxygen and above a certain ratio a mixture is also explosive. But hydrogen is about 14 times lighter than air and therefore extremely volatile. If H2 escapes from a vehicle tank, for example, it rises faster than it can combine with the ambient oxygen. In a fire test conducted by U.S. researchers in 2003, the fuel cell car caught a flash fire, but it quickly went out again. The vehicle remained largely unharmed.
Timing: The production of hydrogen is proven and technologically controllable, says Bosch. Production can therefore be ramped up quickly if there is sufficient demand. In addition, the fuel cell has now reached technological maturity for industrialization and widespread use. Provided that there is sufficient investment and political will, the hydrogen economy can become competitive in the next ten years, according to the Hydrogen Council.
“The time to enter the hydrogen economy is now”, says Uwe Gackstatter, Chairman of the Bosch Powertrain Solutions Division. Does this mean that battery-electric propulsion is outdated or that Bosch is no longer committed to the development of such drives? No, the company makes clear: Both concepts will complement each other and coexist.