Client corner: 6 questions about hydrogen as fuel

As a zero-carbon fuel, hydrogen represents a key solution for shipowners looking to reduce their emissions. But questions remain surrounding the development of this zero-carbon fuel, and how it will be sustainably produced, safely stored and used onboard.

1. What are the challenges of using hydrogen as fuel?

The key challenges for hydrogen as fuel are managing safety and storage. Hydrogen is both explosive and flammable, so safety concepts for ship system designs must be developed. Operational safety needs to be addressed for crew, who must receive specific training on how to handle hydrogen systems onboard. Hydrogen also has much lower volumetric energy density as compared to other fuels, meaning that greater volumes of it must be stored onboard. As a gas, hydrogen must be compressed and stored under extremely high pressure; as a liquid, it must be stored using cryogenic technology at temperatures of -253° C.

2. What technologies are being developed to enable ships to use hydrogen as fuel?

Technology providers are looking into ways to store hydrogen in liquid form onboard ships, building on existing Type C tanks by improving insulation performance. It is possible that other tank solutions may emerge from research and innovation. Fuel cell power systems, which are already common on land, are being reworked for use onboard ships. Meanwhile, engine manufacturers are in the preliminary stages of developing internal combustion engines that use hydrogen as fuel, with some companies having already built prototypes.

3. What is the difference between black, grey, blue and green hydrogen?

When hydrogen is produced using coal as an energy source, it is known as black hydrogen; when produced using natural gas, it is referred to as grey hydrogen. About 95% of hydrogen produced today falls into these two categories.

Decarbonized hydrogen comes in two forms. Producers using fossil fuels can apply carbon capture, use and storage during the production process, developing what is known as blue hydrogen. Alternatively, they can produce hydrogen from renewable electricity via electrolysis: this is known as green hydrogen, and is the most sustainable solution.

4. How can the development of green hydrogen be assured?

While there are many possibilities for procuring the renewable energy required to produce green hydrogen, the marine and offshore industries are home to two key options. Stakeholders are looking to offshore wind farms to provide renewable electricity for use in green hydrogen production. Offshore installations can also be used to store hydrogen, sending it to shore as a gas, or using it onsite to create green electricity. Projects like these are largely in the planning and pilot stages, and are mostly underway in European countries.

5. What legislation exists to regulate hydrogen as fuel?

The existing international regulatory framework states that hydrogen-fueled ships must comply with the International Convention for the Safety of Life at Sea (SOLAS) and Part A of the IGF Code. Shipowners must be able to prove the safety of their alternative designs for hydrogen-powered vessels to the relevant flag administration, and should work closely with a classification society during the design phase.

6. What is Bureau Veritas doing to advance hydrogen as fuel?

Our experts are working on a variety of innovative projects using hydrogen as fuel or in fuel cells. We are supporting French shipbuilder Piriou in developing a hydrogen-fueled dredger for the Occitanie region of France, and will help French owner Sogestran integrate hydrogen onboard a deck cargo vessel following construction, and supporting a fuel cell project for a shuttle passenger vessel.

In July, Bureau Veritas published a class notation for fuel cells, and in late 2021 we will update our guidance note for fuel cells based on IMO’s latest updates. We are also currently developing classification rules for hydrogen-fueled vessels, to be published in 2022.