Bring back the airship to reduce carbon emissions from oceangoing cargo ships and help establish a sustainable hydrogen-based economy. That's the suggestion of a new study by an international research group.
The International Institute for Applied Systems Analysis, headquartered in Laxenburg, Austria, published the study last week in the journal Energy Conversion and Management: X. (The article is freely available online without a subscription.)
Here's how the airship plan would work, according to the study:
- Airships or balloons filled with hydrogen would transport some cargo now carried by maritime ships (which generate 3% of the world's carbon emissions). An airship is a lighter-than-air craft that can navigate under its own power, like the propellor-driven dirigibles that flourished between the world wars until the spectacular flaming crash of the Hindenburg in 1937 killed 36 people. A dirigible can have a rigid frame, like the Hindenburg, or maintain its shape from internal gas pressure, like the Goodyear Blimps. A balloon has no frame or propulsion, so it's lighter than an airship. It can be steered only by varying altitude to seek winds blowing in the desired direction.
- The aircraft would use the high-speed air currents known as jet streams to boost their speed. Jet streams flow 8 to 12 kilometers (5 to 7.5 miles) above the surface, average about 110 miles per hour, and can exceed 250 mph. They blow west to east, so an aircraft flying from New York to London would have to keep going east around the world to return to New York. Therefore, the study suggests, "Long-distance routes should be prioritized."
- Advances in materials and technology since the 1930s could allow a safe return to hydrogen for lift. After the Hindenburg disaster, airships switched from highly flammable hydrogen gas to helium, which is not only nonflammable but also fire-suppressing. Hydrogen is lighter and much more readily available than helium.
- Not only could such aircraft carry cargo faster than surface ships, but the hydrogen itself could be cargo. As hydrogen fuel cells increasingly power cars, trucks, and even ships themselves (emitting only water vapor and warm air), hydrogen will become a more valuable commodity. Airships could offload some of their hydrogen along with the rest of their cargo at their destination. Keeping 20% to 40% of the hydrogen could provide enough lift to get the aircraft back home without cargo.
"The development of an airship industry will reduce the costs of fast delivery cargo shipping, particularly in regions far from the coast," said Julian Hunt, a postdoctoral fellow with the institute and lead author of the study. (He was quoted in an institute news release.)
"The possibility to transport hydrogen without the need to liquefy it would reduce the costs for the development of a sustainable and hydrogen-based economy, ultimately increasing the feasibility of a 100% renewable world."