Prime Minister Boris Johnson has announced further investment of hydrogen technologies, while new funding initiatives for energy efficiency and electric vehicles (EVs) are also in the pipeline. But how does hydrogen compare with other green energy alternatives? Here Simone Bruckner, managing director of power resistor manufacturer Cressall, investigates the pros and cons of hydrogen for the automotive industry.
Recent hydrogen vehicle developments have given hope to the idea that hydrogen will one day “dominate” the market. However, for now, it seems that competing battery electric vehicle (BEV) technologies have taken pole position as the technology that could remove fossil fuels from our roads. Why is hydrogen falling behind alternatives, like BEVs?
A clean solution?
To power vehicles, energy-dense hydrogen is stored in a fuel cell. Using hydrogen and oxygen as power, the fuel cell produces water, electricity and heat, without creating any emissions, other than water vapour.
Hydrogen fuel has many benefits, offering a slightly better range and a more promising consumer uptake than BEV alternatives. This is mainly because vehicles will only need to adjust to using a different kind of gas and they can be refueled in times comparable to fossil fuel powered cars.
As with all new technologies, there remain some barriers to hydrogen adoption. One obstacle to the widespread adoption of hydrogen fuel cells is that the technology requires an entirely new charging infrastructure.
Another issue that throws our hydrogen readiness into question is the current price point of hydrogen vehicles. Paired with the needed infrastructural developments, the future could be hydrogen, but it is certainly not the present.
Hydrogen’s water-only emissions may seem like a green alternative, but sustainability still poses problems. Currently almost all the hydrogen sold in the UK is produced by splitting it from natural gas, which is costly and emits carbon dioxide (CO2).
However, this problem can be tackled by capturing the CO2 during hydrogen production, then ‘burying it’ with carbon capture and storage. But that will drive up costs. The alternative entails using surplus renewable electricity to split hydrogen from water using a fuel cell, offering a cleaner yet more expensive solution.
An electric dream
BEVs offer their own set of benefits. Electric motors can deliver torque quickly with almost instant acceleration, making vehicles quicker to start. Charging infrastructure is also far more developed than hydrogen refuelling capabilities, with more than 18,000 charging devices currently dispersed across the UK.
As BEV uptake increases, with a robust charging infrastructure already in place, it will be wise to continue investing in EV technologies while driving forward with hydrogen technology.
In addition to battery technology, resistors also play an important role in EV efficiency. When an EV’s battery is full, the vehicle must rely on its mechanical friction braking system to slow the vehicle. When slowing the vehicle, it is beneficial to use a resistor to discharge the excess energy. Not only is the resistor useful in the event of an electrical fault, it also lowers servicing costs due to reduced wear on the friction braking system.
The energy dissipated during dynamic braking into the resistor can also heat the vehicle’s cabin, reducing the requirement for electrical heating, which places an extra load on the battery. Cressall produces the EV2 resistor, a liquid cooled modular resistor with a 25 kilowatt (kW) rating that can be mounted outside or even underneath the vehicle, making it ideal for both small electric cars and larger forms of transport.
While the UK looks forward to the benefits of hydrogen, much has still to be done to make it a commercially viable fuel. Meanwhile, competing technologies like BEVs, paired with other high-tech components like advanced resistors, can continue to drive the automotive industry’s green revolution forward.