As Hydrogen’s potential as a clean, renewable and scalable energy source is becoming clear, there are differing opinions in the market over the optimal way to store the large volumes of H2 needed for various power applications.
Hydrogen is the lightest, and arguably the most powerful, element of all. Considering these two facts, the challenge of providing a significant amount of hydrogen to a fuel cell or combustion engine starts. Therefore, it needs to be stored at high density in order to contain enough fuel within a feasible space to drive a fuel cell in a mobile application like a truck or a train. The two most accessible ways of achieving this are: storing the H2 as a highly compressed gas; or as a cryogenic liquid.
There are pros and cons of both approaches. Due to its significantly reduced volume, liquid storage can work better when vast quantities are being transported. For example, cryogenics is often considered for the transportation of large volumes of hydrogen, as we see with distributing natural gas from the Middle East in giant tanker ships.
However, this option does not offer an adaptable solution for the modern variety of ways in which hydrogen can be used. At NPROXX, we believe that the battle over everyday hydrogen storage already is, and will continue to be, won by high-pressure gas, stored in strong, light carbon fibre type IV pressure vessels.
Why store hydrogen as gas?
- Issues with cryogenic storage
As with any cryogenic liquid, hydrogen stored in this way comes with a lot of problematic considerations. One of the major drawbacks is the cost; liquid hydrogen requires well-insulated cryogenic storage vessels that maintain its required temperature of -252.8°C.
- The cost of conversion
In cryogenics, the gas-to-liquid transformation process consumes up to 30% of the energy content of the stored hydrogen. There are also hazards associated with converting liquid hydrogen back into a gas, which this makes this a particularly unappealing option.
- Speed and simplicity of delivery
The main advantage of employing a compressed hydrogen gas storage system is that it allows individuals to rapidly refuel their vehicles. With a high-pressure gas storage system, refuelling can be achieved in minutes, while liquid storage refuelling protocols and processes are not yet available.
- Storage footprint
The storage of cryogenic solutions is even more inefficient and costly. Liquid storage requires excessively large footprints – about three times the size of industry-standard gasoline tanks, for example – to cope with both housing the chemicals and performing onsite conversion.
For these reasons, NPROXX believes that pressurised gas storage is the best way forward. If you would like to find out more about high-pressure hydrogen gas solutions from NPROXX, visit our transport & storage page to learn about how our products are revolutionising the hydrogen storage industry for both stationary and mobile applications.