When Solar Ship completed its flight of a hydrogen-inflated airship prototype inside our testing lab, it freaked a few people out. People are afraid of hydrogen. But there is a difference between fear and danger. Hydrogen flights are an important milestone on the path to a full-scale airship operating commercially.
There are only two practical options for airship gas: hydrogen or helium. Hydrogen is flammable, helium is not. Hydrogen is inherently less safe than helium, but that doesn’t mean it’s inherently unsafe, or that it cannot be used safely. A key part of any product development involving flammable materials is figuring out how to make it safe.
Solar Ship is taking a step-by-step approach, at each step proving hydrogen safety to ourselves, our investors, customers and the public. The first step was testing material used to build the airship’s envelope, to ensure it wouldn’t create any static shocks that could ignite the hydrogen. The next step was destructive testing, where researchers tried different ways to ignite a balloon and observe how it burns. Our team of engineers, always eager to blow things up, described the results as “boringly safe”. Once that baseline of safety was established, we proceeded with inflating and flying a small prototype airship. Now that this has been done safely, we’re moving on to a larger scale. With each step we gain believers in hydrogen safety.
This process builds a body of evidence we can use to make others more confident in hydrogen. People are fearful of the unfamiliar. A decade ago the launch of the modern electric vehicle (EV) suffered a major blow after an EV caught fire following a routine crash test, creating concerns that EVs can unpredictably burst into flames. These days, when EVs are much more familiar to the average person, those concerns seem ridiculous. It took time to build public trust in EVs; it will take time to build trust in hydrogen fuel cell EVs. And it will take time to build trust in hydrogen aircraft.
Bit by bit we’re building that trust.
Why do we bother? Why not just use helium? For starters helium costs up to 20x more, adding millions to the cost of a large airship and potentially costing more than the airship itself. Secondly, helium is a scarce commodity that cannot be produced on site and must be transported to wherever an airship operates. Airships are often designed for remote areas, making helium transportation challenging and expensive. In many remote areas, you cannot get helium at all.. Hydrogen can be produced on site anywhere with renewable energy and an electrolyzer. Finally, helium is heavier than hydrogen and takes up payload capacity. An airship inflated with hydrogen might have 10 tonnes available for cargo or passengers, while that same airship inflated with helium might have 9 tonnes available. For these reasons safely-managed hydrogen is the only commercially feasible option.
Hydrogen also has a broader role to play in aviation, replacing fuel and engines with hydrogen, fuel cells and electric motors as the world transitions to low carbon transportation. Unlike electric cars, which predominantly use batteries, weight is critical for aircraft and a hydrogen fuel cell system can provide 3x as much useful energy as a battery system with the same weight. Neither can match the performance of conventional engines in conventional aircraft, but hydrogen is the most promising candidate for zero emission flight. This is why companies like Solar Ship, ZeroAvia, Airbus and others are building their future designs around hydrogen propulsion systems. New innovation in unconventional aircraft opens new possibilities to far outperform conventional engines. Hydrogen has three times the energy density of fossil fuel – for innovators, hydrogen offers exciting possibilities.
Hydrogen will play a critical role in the future of aviation.
Step by step, Solar Ship is working to make that future a reality.