Storing Hydrogen for Cars: Methods, Technologies, and Prospects

While electric vehicles (EVs) have seen a significant increase in popularity, the challenge of storing hydrogen for cars remains an important topic for future transportation technologies. This article explores the methodologies and technologies involved in storing hydrogen for automotive use, along with the current status and future prospects of hydrogen-powered vehicles.

Introduction: The Current Standstill in Hydrogen Vehicle Adoption

Despite advances in hydrogen technology, the adoption of hydrogen vehicles (HVs) has not matched the rapid growth of electric vehicles (EVs). Currently, there are approximately 18,000 hydrogen vehicles in operation worldwide, with California leading the way. In comparison, over 2.5 million EVs have been sold globally, resulting in a ratio of EVs to hydrogen vehicles of 138:1. This stark contrast highlights the current challenges in the widespread adoption of hydrogen vehicles.

Storage Methods for Hydrogen in Cars

The storage of hydrogen is a critical aspect of hydrogen-powered vehicles, as it directly impacts the vehicle's range, performance, and overall usability. One common method involves storing hydrogen in cylinders or gas tubes with pressures ranging from 200 to 500 bar. This approach is particularly favored by composite overwrapped pressure vessels (COPVs), which are lightweight and suitable for large-scale transportation and storage. COPVs provide a viable solution for long-term storage and transport, making them ideal for both passenger cars and commercial vehicles.

Tank Technologies and Methods

Hydrogen can be stored in several ways, including compression and liquefaction, each with its own advantages and challenges.

Compression: Hydrogen can be stored by compressing it into lightweight carbon fiber tanks. This method is widely used and has become the standard. The hydrogen tanks are known as H70 tanks, following ICCT standards. These tanks are typically self-serve and located on gas station plazas, offering a familiar and user-friendly experience. The H70 dispensers are strategically placed beside gasoline and diesel pumps, providing a seamless transition for drivers looking to refuel their hydrogen vehicles.

Liquefaction: While compression is a popular method, hydrogen can also be stored through liquefaction. This involves cooling hydrogen to extremely low temperatures to convert it into a liquid state. The process requires insulation and an overpressure vent, ideally coupled with a small, continuous cooling unit. Liquefaction offers higher density storage but is more complex and expensive to implement compared to compression.

Current Status and Future Prospects

On the ground, hydrogen storage technologies for cars are making progress, but significant hurdles remain. The California Fuel Cell Partnership, for instance, is one of the key players in this field, actively promoting hydrogen vehicle infrastructure and technology development.

The global scenario is seeing efforts to overcome the challenges associated with hydrogen storage. Advances in material sciences, specifically in the development of advanced composite materials, are addressing issues like weight and durability. Furthermore, ongoing research into more efficient compression technologies and the potential for large-scale hydrogen storage are promising areas that could lead to increased adoption of hydrogen vehicles in the future.

While the future of hydrogen vehicles may seem uncertain, the technological advances and sustained efforts of organizations like the California Fuel Cell Partnership are ensuring that hydrogen remains a viable option for the transportation sector. The ongoing research and development in hydrogen storage and infrastructure will play a crucial role in determining the future landscape of clean and sustainable transportation.

Keywords: hydrogen storage, cars, fuel cells, EVs, hydrogen tanks