This article was contributed by:
Stephen Learney
SME Hydrogen Refueling
Consultant
Neil McPherson
Filtration Alternative Energy Manager
Parker Hannifin
Let's Talk Hydrogen - The Future of Refuelling Stations
April 15, 2024 by Stephen Learney and Neil McPherson
How to operate a hydrogen refuelling station efficiently and reliably?
It’s fair to say that there’ve been efficiency and reliability issues with all the early stations deployed into the public domain.
The main reasons being that the available hydrogen process technology was not originally designed for a refuelling station environment, in combination with some unique properties of hydrogen gas itself.
To start with, hydrogen’s energy density is lower than that of petrol or diesel. This means that if you filled the fuel tank of your petrol car with hydrogen, you’d have less energy stored than with petrol. To get the same energy and therefore the same driving range, hydrogen needs to be compressed and stored under high pressure, much like CNG, but higher pressure.
Pressurising, storing, and moving hydrogen under high pressure, requires a range of technology that, while it’s been around for a long time, has never been manufactured in high volumes or had the high frequency 24/7 365 days a year operational demands required for a refuelling station.
That said, available technology is continuously evolving, and to date, while on this learning curve, incidents have been thankfully very rare – indeed much rarer than when petrol stations began to appear in public (for example, the National Fire Protection Association, reported as recently as 2018 over 5,000 petrol station fires recorded in the USA alone).
Also, we are slowly seeing standardisation of station design. This is a critical step towards performance and reliability improvement as well as cost reduction – just as we’ve seen in every other new technology – and standardisation is absolutely needed to enable infrastructure roll-out across the world and to meet the net zero emissions targets for transportation.
Already capable of supplying almost 1/5th of the components on a hydrogen refuelling station, Parker is uniquely placed with its range of technology and depth of product development resources to design and supply almost half of the total equipment – equipment which is then purpose engineered and where needed, parts designed to communicate with each other.
Add this to Parker’s global manufacturing and product support capability, and you have a situation where performance and reliability will improve exponentially, and cost will be driven down through standardisation.
How does hydrogen gas quality impact the operation?
You need to start thinking about this from the position of the vehicle. Hydrogen cars are electric vehicles, with a fuel cell replacing the battery of a standard EV. The fuel cell converts Hydrogen into electricity plus water. The electricity powers the vehicle, and water is exhausted. The fuel cell needs very high purity hydrogen.
In the context of a refuelling station, hydrogen with a purity 99.999%, also known as ‘5 nines’ purity is delivered to the station. The hydrogen then passes through 10’s of meters of pipework and valves, through a chiller system, through a compressor, then more meters of pipework and valves into storage, then more meters of pipework until it reaches the head of the dispensing nozzle – all of which must be done without picking up any impurities or moisture.
The task of maintaining the gas quality throughout the total refuelling system is vital to the ultimate performance and durability of the fuel cell and therefore the vehicle.
Maintaining hydrogen gas quality throughout the system is a challenge. Dispensing hydrogen containing impurities has the potential to reduce fuel cell efficiency and longevity – something that we want to avoid at all costs.
Fortunately, the Filtration Group within Parker has an extremely broad range of technologies and products which can be applied to the hydrogen market. We protect and purify gases in some of the most critical and demanding applications – for example in the food and beverage and life science markets.
We are leveraging our technology and know-how to assist hydrogen refuelling station manufacturers with their gas purification needs.
How cooling can impact the vehicle dispensing?
Where most gases cool down when pushed through an orifice such as the refuelling dispenser nozzle or gun, hydrogen heats up, because of a thermodynamic property known as the Joule-Thomson effect. If not controlled, this could overheat the composite material used in the construction of the on-vehicle fuel tank, which needs to be kept below 85C.
To achieve this, while at the same time filling a vehicle at the same speed as you fill with petrol or diesel, you need to pre-chill the hydrogen so that it reaches the dispensing nozzle at no more than - 40C before it gets heated up while passing from the refuelling nozzle into the fuel tank.
How fast is the hydrogen refuelling?
The aim is to make both the refuelling and driving experience of a hydrogen vehicle identical to that with petrol or diesel. Today’s technology already achieves this goal with the refuelling of a Toyota Mirai taking only 3 minutes and delivering a driving range of over 600km.
Refuelling larger vehicles today takes longer at around 10-15 minutes, however high-speed filling technology, including Parker’s purpose engineered high flow 1000 bar rated refuelling hose is now commercially available and being introduced.
Hydrogen refuelling station market in the coming years, share experiences.
While California was one of early adopters of hydrogen refuelling for cars in the early 2000’s, development never really expanded into the rest of the USA. Instead, Europe swiftly became the hub of product development and infrastructure roll out, the earliest stations being manufactured for demonstration and test, and slow introduction to the public. Now there are approximately 270 public stations in Europe, 100 in N. America – almost all in California, and in the last 5 years its Japan, South Korea and China that have really pushed ahead rapidly with around 550 now operational in the region; and last year and this year China will open more stations than the rest of the world combined, with a stated aim to have 1200 stations by 2025 – almost half of the world’s stations.
Europe will continue to grow steadily through the decade, aiming to have a Europe-wide joined up network between 2030-2035. The USA, kick-started by the Inflation Reduction Act, s predicted to have rapid growth through the rest of the decade. The Hydrogen Council forecasts a total global capacity of 10,000 stations by 2030, meaning 9,000 stations need to be manufactured and opened. The reality is that investment in the supply chain in combination with government dithering over the release of funding, will result in missing the forecast by as much as 25%, though this still means around 7,000 stations will be built in the remainder of the decade, representing a very attractive CAGR for the industry of over 20%.
How Parker can be part of the market and meet the customer challenges?
As mentioned during this discussion, Parker Hannifin is very well positioned for the technology transition. We have a broad product offering across multiple core technologies. Today, we can supply about 20% of the components required to build a refuelling station.
Parker engineering colleagues strive to develop technology aligned to the market needs. To stay up to date, we listen carefully to our customers and participate on industry standardization committees.
To serve new and emerging “hydrogen” customers better, we’ve realigned our engineering and commercial teams. We have Parker colleagues across the globe dedicated to the hydrogen market, who can help customers with their needs.
In this dynamic space, we partner with our customers to support the energy transition.
By supplying innovative products and solutions, Parker Hannifin can help refuelling station manufacturers improve their system design, maximising uptime, and reliability.
Two key goals that must be achieved to support the widespread adoption of hydrogen refuelling station technology across the globe... technology that will reduce emissions from transportation and ultimately lead to a better tomorrow.