Hydrogen & Transport Part One | Exploring the pros and cons of hydrogen for transport

The role of green energy in the global transport sector is undoubtedly gaining momentum, but the question remains whether the Hydrogen-fuelled revolution can deliver an efficient and sustainable solution to the fossil fuel dependency.

With 2023 seeing the publication of the UK Government’s Powering up Britain: The Net Zero Growth Plan in March 2023, the commitment towards developing a pathway for production of all alternative sources of green energy was cemented. Whether the growth plan goes far enough is a debate that will continue in the months to come, but what is clear is that the development and production of Hydrogen is a critical component of the UK’s strategy to deliver energy security, drive economic growth and support net zero. 

With over 200 companies working on hydrogen and fuel cell technologies in the UK (many being in the transport industry) and the UK consistently featuring in the top ten countries globally for hydrogen technology patent rates, many commentators believe that in some use cases Hydrogen can be a viable alternative to the dominance of battery-powered electric vehicles in the race to Net Zero. 

As the British Energy Security Strategy effectively doubled the UK’s Hydrogen production ambition (to now deliver up to 10GW of low carbon Hydrogen production capacity by 2030), the purpose of this article is to shed some light on the benefits and drawbacks of this technology in its unquestionably inevitable role in decarbonising the transport sector.

The UK’s Net Zero Mission Statement

Reducing emissions across transportation will play a critical role in achieving Net Zero by 2050. As of 2020, the transport sector accounted for almost a quarter (24%) of the UK’s greenhouse gas emissions, with evidence indicating that this figure will rise as the UK exits the Covid lockdown era.

Since the UK government’s announcement of its ‘Net Zero Strategy’ in 2021, there has been no doubt the decarbonisation of the transport sector would require a hydrogen solution in conjunction with electrification to deliver its promises. The popularity of electrification across various modes of transport is undisputed, particularly in the private car industry. However, with typical EVs being powered by lithium-ion batteries there are unseen challenges that the consumer would generally not be privy to. Taking 2.2 million litres of water to mine one tonne of lithium (along with the controversial conditions for the miners themselves), these finite batteries start their life laden with a significant environmental footprint. Combine this with the extensive difficulties in safely recycling lithium-ion batteries (with only approximately 5% being recycled), the rush to ‘go electric’ comes with a hidden toll. Therefore, in conjunction with electric-based pathways to Net Zero, the UK government is committed to the design and implementation of a hydrogen-based business model across the transportation sector, as evidenced by its ongoing (as of November 2022) industry consultation[1] on hydrogen’s specific role.

In order for this to happen, a clear understanding of the advantages and disadvantages is required to shape policy, target investment and direct activity.

Hydrogen: Assessing the Technology 

In addition to the natural resources challenges alluded to above and the cost implications inherent in delivering an electrification solution, the debate between hydrogen and electrification is often a balance between the associated weight versus range (distance of travel) and charge times. There are several advantages and disadvantages to hydrogen technology: 

The advantages of hydrogen fuel cells over electrification: 

• Each kilogram of battery weight to increase EV range requires extra structural support, increased torque, heavier brakes, and in turn more batteries to carry the extra mass. Ironically, all this extra weight in turn limits the vehicle range. With hydrogen, due to its energy density, weight compounding is not an issue: it is able to deliver an extended range without adding significant load;
• Hydrogen fuel cells can continue to generate electricity as long as there is a continuous supply of hydrogen, without the need to be ‘re-charged’. This means that refilling a depleted hydrogen fuel cell is broadly analogous to petrol/diesel and is therefore a far quicker process than charging an EV;
• Fuel cells can be “stacked” to form larger systems capable of producing more power, thereby allowing scalability; and 
• Because there are no moving parts, fuel cells emit very little noise and are highly reliable.

The disadvantages of hydrogen fuel cells

• Although hydrogen can be stored in different states (i.e most commonly in liquid and gas), there are challenges with both options. The main problem in the storage of gaseous hydrogen is the low storage density which is related to storage pressure. High storage pressures require significant investment and incur increased operating costs. As the amount of hydrogen to be stored increases, so will the cost. The difficulty with liquid hydrogen is the evaporation losses in the production and storage of liquid hydrogen. Total losses from liquefication to final use are between 30 and 70%.
• Despite numerous fail-safes, there is no hiding from the fact that hydrogen is extremely flammable. A simple spark or a minor increase in temperature has been known to cause major explosions. 
   

It’s clear that there’s much to be gained by adding hydrogen to the low carbon transportation mix as the UK pushes towards Net Zero, but there are several challenges along the way that must be addressed. 

In the next part of this series of articles, we’ll explore some of the key market drivers that are shaping the adoption of hydrogen or present future opportunities in different transport sectors. And we’ll investigate some of the critical challenges that apply to the low carbon hydrogen transportation market as a whole.