It’s important to understand the limits of batteries and hydrogen fuel cells, as well as how they can complement each other.
The historic Paris Agreement of December 2015 set out to reach net carbon neutrality by 2050. Confirmed by the members of the United Nations Framework Convention on Climate Change (UNFCCC), the agreement aims to keep global warming below 2ºC by the year 2100. But the world needs more than just renewable energy to decarbonize all sectors of the economy and to meet climate and sustainability goals.
This article will discuss two clean energy sources—batteries and hydrogen—as important decarbonization tools for different sectors, especially transportation. Both technologies convert electricity into chemical energy and vice versa, and thus they can be used as compact energy storage systems and portable energy sources. Since these technologies have a similar purpose, two main questions arise: are these technologies competitive, and is there enough room for both?
Comparing Batteries and Hydrogen Fuel Cells
Although both batteries and hydrogen fuel cells are electrochemical devices used as power sources, comparing them is challenging, because they provide power in different ways. Batteries in electric vehicles (EVs) store energy and directly provide power to the propulsion engine. Fuel cells in EVs generate electricity from hydrogen and then deliver it to the vehicle’s engine, or use it to charge batteries. Fuel cells have limited performance when it comes to responding to dynamic changes of powertrain energy demand.
Electrolyzers are devices that produce hydrogen from water by splitting it into hydrogen and oxygen via electrical energy. This can be a green solution when electricity is derived from renewable sources. So-called green hydrogen can be an effective tool for sectors where reducing emissions is a challenge, such as shipping (marine or truck), aviation, and the steel or chemical industries.
The Current Market and Future Expectations
Both batteries and hydrogen fuel cells are well-suited for mass manufacturing. Currently, battery technology is developing faster than electrolyzers, and battery prices are decreasing due to higher production volumes. However, experience in battery production can be used in the future development of electrolyzers because both technologies share common parts such as an electrolyte and membrane.
The world´s current battery production capacity is around 320 GWh per year for use in EVs, and it is expanding rapidly. Sufficient production capacity is a key factor in decarbonizing the road transport sector. However, to comply with targets for electric vehicle production through 2025, manufacturing capacity must be increased to 1000 GWh per year. This is approximately equivalent to 50 Tesla Gigafactories. Once that target is reached, 1500 GWh of capacity per year will be needed until 2030. The biggest battery manufacturing companies (CATL, Panasonic, LG Chem, BYD, Northvolt, etc.) have set their capacity targets to around 2100 GWh per year until 2030.
Batteries have the greatest potential to be a key player in the energy market. With government stimulus, massive manufacturing of stationary battery systems can also lead to the rapid deployment of wind and solar technologies as primary clean energy sources. Generally supporting battery production will decrease the costs of all battery-supported technologies, making them competitive to equivalent fossil fuel technologies. This will speed up the transition to clean energy. The importance of decreasing the cost of batteries is underlined by the fact that in EVs, the battery system is around 40 percent of the total vehicle cost.
Electrolyzer production technology is still in its early stages. Europe is currently leading electrolyzer production with a capacity of 1.2 GW per year. To get a sense of the amount, this is enough to power 500,000 fuel cell passenger cars. The production capacity is rapidly growing. The United Kingdom’s ITM Power is building the world’s largest electrolyzer plant with a planned capacity of 1 GW per year.
There are two main ways to produce hydrogen. Green hydrogen is produced using 100 percent renewable electrical energy to convert water to hydrogen. It can also be done locally at a tank station. In contrast, blue hydrogen is produced from natural gas and is not accepted as a decarbonization tool.
To make an effective stimulus package, governments must focus on green hydrogen and its potential in sectors such as transportation, iron and steel production, and the chemical industry. Developing and building the supply infrastructure for hydrogen is a crucial factor.
Pros and Cons of Hydrogen Fuel Cells
If produced in an environmentally friendly way, hydrogen could play an important role in decarbonization. Hydrogen fuel cell vehicles could provide a good transition from fossil fuels to fully electric cars. Filling the tank does not take much time and is quite similar to fossil fuel cars, so drivers can get more distance than they would with an EV. Hydrogen fuel cells are much more robust than batteries and have a longer operating life. Current gas station infrastructure could be adapted for hydrogen.
Still, there are many challenges and limitations with hydrogen, especially when compared with batteries. Hydrogen requires much more electricity to power a vehicle than batteries do. There are significant energy losses in the production, distribution, and conversion of hydrogen back to electricity.
Repair and maintenance must also be considered, because the expectation is that the maintenance of hydrogen vehicles will be more expensive than battery electric vehicles. After all, their systems are more complex (for example, the cooling systems). Additionally, hydrogen is a volatile gas requiring more maintenance to ensure the required safety.
Room for Both Batteries and Hydrogen
There are many reports and analyses which suggest that hydrogen should be used as a decarbonization tool, but not in passenger cars. Here, battery EVs are a much better and established solution with minimal environmental impact. Currently available hydrogen technology is not on the level of battery technology, and there are challenges with safety, efficiency and design. Elon Musk has noted that even the theoretical technology limit of hydrogen fuel cell cars is not as good as current battery EV technology.
To decarbonize the transportation sector, heavy transport vehicles must also be taken into consideration. Hydrogen can play an important role in this.
Although many think that only battery electric technology is the solution for decarbonizing the transportation sector, large vehicle manufacturers are exploring alternative fuel systems, including hydrogen fuel cells. Hydrogen can be more efficient for heavy vehicles intended for a long-distance transport. Batteries are large, expensive and heavy for this application, with recharging speed limitations.
Both battery and fuel cell technologies will complement each other in the transportation sector. Truck manufacturers such as Toyota, Honda, Scania, and Volvo have pinned hydrogen as a promising sustainable transportation solution. Last year, Volvo Group joined forces with Daimler Truck AG to develop fuel cell technology for demanding applications.
Although some may see batteries and hydrogen fuel cells as competing technologies, they can work side by side to help decarbonize the transportation and power sectors.
Conclusion
Currently, battery electric is the best-developed technology and the leader in enabling carbon-free transportation. There is no doubt that batteries are a key decarbonization tool for the transportation sector. But where they fail, such as in marine or heavy truck applications, hydrogen fuel cells can provide solutions for carbon-free transportation. Policymakers should focus on which technology is more suitable to a certain application and which best meets customer needs, rather than on which technology is better in theory.
It bears mentioning again that only green hydrogen, produced using 100 percent renewable energy, can be discussed as a decarbonization tool. Studies indicate that it is always more effective to use renewable energy directly from the grid instead of green hydrogen. Because of energy losses in converting renewable energy into hydrogen, using hydrogen requires more renewable energy than using electricity directly.
Like battery technology, hydrogen fuel cells also need government support to be able to provide cost-effective solutions. Policymakers should focus on supporting green hydrogen usage in sectors that lack feasible electric options. Green hydrogen can be used as a replacement for hydrogen massively produced in fossil fuel industries, which significantly affects the climate.
In the transportation sector, green hydrogen has potential in long-distance maritime shipping or the aviation sector, where batteries have limitations in their capacity and recharging capabilities. Hydrogen has good potential in the long-term storage of renewable electricity in the form of fuel cells, providing cost-effective storage solutions that can convert green hydrogen into electricity when needed.
