Rolls-Royce Successfully Tests Its First Hydrogen-Powered Jet Engine

Although it is a vital component of the global economy, aviation is a significant contributor to harmful greenhouse gas emissions. A move in the right direction could be provided by the first-ever hydrogen jet motor.

Contrary to land transportation, aircraft has strict weight restrictions, making it difficult to decarbonize using batteries. Even with great advancement, the energy density of today's most sophisticated lithium-ion cells is still significantly lower than that of traditional aircraft fuel. Energy density is a measure of how much electricity can be packed into a pound.

This presents a challenge for airplanes because it means that having more batteries won't produce enough additional power to make up for the additional weight of the batteries. Even at its potential maximal capacity, lithium-ion technology won't deliver high enough energy densities for even medium-haul flights, and novel battery chemistries are still a long way off.

Because of this, interest in hydrogen as a possible aviation fuel is increasing. Although it still lacks kerosene's energy density, it has a lot more power than batteries and emits no pollutants when consumed.

Though it's not a direct replacement for jet fuel, using hydrogen to power aircraft will necessitate major redesigns. However, the first ground demonstration of a jet engine powered by hydrogen was conducted by business airline easyJet and jet engine manufacturer Rolls-Royce.

The accomplishment of this hydrogen test, according to Grazia Vittadini, chief technology officer at Rolls-Royce, "is an exciting milestone." We are pressing the envelope to learn more about hydrogen's zero-carbon potential, which could help reshape the future of flying.

The demonstration was carried out using a modified Rolls-Royce AE 2100 engine and hydrogen generated by the European Marine Energy Centre on the Scottish Orkney Islands using sustainable tidal energy.

It's crucial to note that not all hydrogen is made identical. The fuel produced by converting water into hydrogen and oxygen while using sustainable energy is referred to as "green hydrogen." The most popular type of hydrogen today, however, is gray hydrogen, which is made from fossil fuels and produces a significant amount of greenhouse gas pollution.

The businesses praised the development as a crucial move in the aviation industry's decarbonization. But before hydrogen is likely to be used to power a sizable number of airplanes, a long distance still needs to be traveled. To begin with, starting an engine on a test device that is located on the ground is very different from using it to propel an aircraft.

Although hydrogen has a higher energy density than batteries, the BBC reports that an airplane would require almost four times as much liquid hydrogen as jet gasoline to travel the same distance.

Additionally, liquid hydrogen must be maintained under pressure and cooled to -253C. The fuel containers and systems required to transport the hydrogen to the turbines would need to be significantly bigger and more complex, necessitating a full rethink of the aircraft. However, despite these difficulties, easyJet is certain that hydrogen is the most practical choice for decarbonizing aircraft.

As easyJet's chief operating officer told the BBC, "We started looking at what might power the aircraft of the future a few years ago." "We looked at battery technology, and it was pretty obvious that it probably wouldn't work for the big business planes we operate. We've determined that hydrogen is a very thrilling idea for us.

Not only them, either. Airbus has been working on several hydrogen-fueled aircraft concepts, and last week it revealed intentions to test a plane's hydrogen fuel cell motor. Fuel cells use chemical processes to transform hydrogen into energy, which can then power an electric engine, as opposed to burning the hydrogen. By 2026, the firm hopes to conduct the first A380 aircraft test flights.

Given the meager quantity of green hydrogen presently generated, it is uncertain whether there will ever be enough fuel to sustain flight, even if these prototypes succeed in leaving the lab. Nevertheless, hydrogen might be a key component of a more environmentally friendly aircraft future, so any advancements are to be commended.

Image Credit: Rolls-Royce