Electricity is generated in a fuel cell through a chemical reaction between the hydrogen fuel and oxygen. Though a fuel cell can use almost any hydrocarbon as its fuel, hydrogen’s advantage is its high energy efficiency. As it can produce electricity without energy-wasting combustion, it is possible to convert 83% of the energy in a hydrogen molecule¹ into electricity - more than double the energy efficiency of a petrol engine.
Hydrogen cars offer multiple benefits, such as no pollutant emissions, lower noise, and operability at low temperatures
In fuel-cell hydrogen cars² the hydrogen is stored in tanks and compressed to an extremely high pressure. It is then converted into electricity through a PEM fuel cell which powers an electrical motor. A rechargeable battery is added to provide additional power for the engine, mainly for braking and accelerating.
Hydrogen cars offer multiple benefits, such as no pollutant emissions, lower noise, and operability at low temperatures. However, as discussed above, infrastructure will be key as large-scale deployment will require refuelling infrastructure and compliance with local regulations, especially on tank safety.
Likewise, vans, buses and trucks can be equipped with the same combination of a hydrogen tank, PEM fuel cell, battery, and electric motor. The use of such technology in towns and cities by the likes of parcel delivery companies, waste disposal trucks, and buses is a particularly fascinating prospect. Because of the cyclical nature of many trips a refuelling station could be centralised and potentially shared between many different vehicles.
As such many analysts believe that heavy-duty trucks and buses could be the most obvious application for initial widespread deployment of hydrogen vehicles.
Impact on automotive industry
While some OEMs such as Tesla are focusing solely on Battery Electric Vehicles (BEVs), many OEMs are adopting a dual strategy and developing capabilities in BEVs as well as Fuel-cell Electric Vehicles (FCEVs) powered by hydrogen.
One report³ states the rapid charging of large batteries needed for trucks is an even bigger challenge than high-performance charging for cars in terms of the infrastructure, parking space and time required. With the decarbonisation of electricity generation, electricity costs 2021 are also likely to increase substantially, potentially turning the current operating cost advantage of BEVs into a disadvantage.
hydrogen has a key role to play in the zero-carbon automotive sector of the future
The rapidly growing demand for hydrogen will also drive a global green hydrogen supply economy that will be sufficient to meet both industrial and automotive needs over the long term, while pricing levels for green hydrogen will be such that its use in the automotive sector will still be relatively attractive versus other industries.
It concludes that hydrogen has a key role to play in the zero-carbon automotive sector of the future. There will be sufficient supply, pricing levels should not be prohibitive, and in many situations the real “source-to-wheel” efficiencies will be attractive versus BEVs.