Understanding Gas vs. Liquid Storage for Hydrogen: Pros and Cons

No category / October 21, 2024

As industries explore hydrogen’s potential, the best way to store this versatile fuel has become a point of debate. The choice between liquid and gaseous hydrogen can significantly impact efficiency, costs, and safety, and each method has distinct advantages and challenges that businesses must consider. With that in mind, let’s explore the key differences between liquid and gas hydrogen storage, along with their pros and cons, to help you determine the best option for your needs.

Gas vs Liquid Hydrogen: Key Differences

As the world embraces decarbonization, hydrogen stands out as a superior fuel. When consumed, hydrogen doesn’t generate harmful greenhouse gasses—it only produces water. Yet despite hydrogen being a promising energy source, it’s not without its challenges.

Like any fuel source, large quantities are needed and storage becomes a central factor. Hydrogen can either be stored in gaseous or liquid form. While liquid and gaseous hydrogen may be composed of the same element, they behave differently.

Let’s look at the properties of hydrogen in its various forms—and how these properties influence storage practices.

Physical States and Properties

In its natural state at normal temperatures, hydrogen is a gas. Like all gasses, natural hydrogen gas has a low density. As such, gaseous hydrogen at 700 bar pressure has a volumetric energy density of 5.6MJ/L (i.e., one liter of gaseous hydrogen can produce 5.6 megajoules of energy).

To become a liquid, hydrogen must cool to -253ºC (-423ºF). Since liquid is denser than gas, liquid hydrogen has a higher volumetric energy density of 8MJ/L.

Production and Storage Methods

There are several different production methods for gaseous hydrogen, including:

Electrolytic processes (splitting water into oxygen and hydrogen)
Thermochemical processes (using heat and chemical reactions to release hydrogen)
Biological processes (relying on microbes to produce hydrogen)

Once collected, hydrogen gas is compressed, enabling more gas to fit in a storage tank or hydrogen hub.

Alternatively, hydrogen gas can be liquified for storage. Liquid hydrogen is ten times denser than its gaseous counterpart, making it easier to transport and store in large quantities. However, as mentioned, liquid hydrogen must be kept at extremely low temperatures.

Advantages and Disadvantages of Gas Hydrogen Storage

When it comes to liquid vs gaseous hydrogen storage, each option has its benefits and drawbacks.

Pros of Gas Hydrogen Storage

Some of the advantages of storing hydrogen in its gaseous form include:

Simpler infrastructure – Because hydrogen gas can exist at ambient temperatures, no specialized cooling equipment is required—pressurized tanks are enough.

Lower energy input – H2 gas requires little energy to store, as there’s no need to maintain cryogenic temperatures.

Established technology – There’s industry familiarity with hydrogen gas; the fuel has long been stored and handled in gaseous form.

Cons of Gas Hydrogen Storage

Despite these advantages, hydrogen gas storage has some issues to note:

Safety concerns – The high-pressure tanks that store H2 gas can be dangerous. If not adequately maintained, the tanks may rupture, resulting in a fiery explosion.

Higher storage volume – Since hydrogen gas is low-density, more space is required to store it—even when it’s under pressure. Purchasing and maintaining additional storage facilities can steeply increase your costs.

Higher transportation costs – For the same reasons, H2 gas is expensive to transport, so it’s rarely shipped over long distances.

Advantages and Disadvantages of Liquid Hydrogen Storage

With these downsides in mind, is liquid hydrogen storage a better option? It depends. After all, liquid hydrogen has its own share of advantages and disadvantages.

Pros of Liquid Hydrogen Storage

Leaders in the energy sector are turning to liquid hydrogen because of benefits like:

Higher energy density – Liquid hydrogen is much denser than gas, so you can store more in a smaller space.

More efficient transportation – Gas can leak during transport through hydrogen pipelines, leading to significant losses. Liquid hydrogen’s storage conditions make escape far less likely. As such, liquid is the ideal form for long-distance H2 transport.

Improved cost efficiency – Liquid hydrogen infrastructure requires some upfront investments, but in the long term, storage and transportation are more affordable. These cost savings make liquid hydrogen an excellent choice for large-scale applications.

Cons of Liquid Hydrogen Storage

Some of the potential downsides of storing liquid hydrogen include:

Energy requirements – Hydrogen liquefaction is an energy-intensive process. Though the benefits of liquefying H2 are well-documented, the operation does incur additional costs.

Storage tank specifications – For hydrogen to remain a liquid, it must be stored in well-insulated tanks. These storage units can be costly.

Losses through boil-off – Although liquid hydrogen is less likely to leak in transit, some energy losses can still occur if the hydrogen climbs above –253ºC and boils off. Luckily, you can minimize these losses through transport optimization.

Choosing the Right Form of Hydrogen Storage for Your Needs

If you want to capitalize on the advantages of hydrogen fuel, you need the optimal storage method for your industry.

Applications for Gas Hydrogen

For those in the automotive or manufacturing industry, gaseous hydrogen may be the more cost-effective and practical choice. Hydrogen gas is well-suited to the following uses:

Local hydrogen refueling stations
Chemical processing
Steel production
Small-scale projects

Applications for Liquid Hydrogen

The use cases for liquid hydrogen are more expansive. Liquid H2 excels in scenarios such as:

Heavy transport and maritime shipping
Long-distance supply chains
Aviation and space exploration

Ultimately, any industry that requires enormous volumes of hydrogen will benefit from liquid hydrogen, as you can store more on-site.

Forecasts and Trends for Hydrogen Storage in the U.S.

While gas and liquid hydrogen will both contribute to decarbonization, liquid H2 will likely remain the frontrunner, especially for large-scale operations. Additionally, there are significant investments in hydrogen liquefaction technology and cryogenic tank efficiency—further contributing to the U.S. energy industry’s ability to leverage liquid hydrogen.

Industry reports estimate that the U.S. hydrogen energy storage market will experience an average growth rate of 5.3% from 2024 to 2030 (moving from USD 3.33 billion in 2024 to USD 4.53 billion in 2030).

With these sizable investments, liquid hydrogen storage will continually become more accessible and cost-effective than ever.

Embrace Hydrogen with FASTECH

Selecting the right hydrogen storage method depends on your specific applications, transportation needs, and operational scale. While gaseous hydrogen storage offers simplicity for small-scale projects, liquid hydrogen's higher energy density and cost efficiency make it ideal for larger, long-distance operations. As hydrogen infrastructure continues to evolve, businesses can look forward to more efficient and sustainable storage solutions.

You can work with FASTECH to explore how we can help implement the best hydrogen storage systems for your industry’s future needs. Reach out today!