"The Transformation to decarbonized aviation is essential to mitigating climate change."

Cristina Rodríguez Levia, Director of Engineering at Skydweller Aero (a solar-powered, autonomous aircraft that can fly for up to 90 days at a time), reveals the potential of innovation in the challenge of decarbonizing the aviation sector.

By Luis Meyer

It takes off, flies and lands autonomously and can stay in the air for 90 days without emitting a single gram of CO2. The Skydweller Aero aircraft, from the start-up of the same name, which has a team divided between Spain and the United States, runs on solar energy and could thus be a new step towards the decarbonization of the aviation sector, together with the development and implementation of biofuels. We spoke with Cristina Rodríguez Levia, the company's Engineering Director.

Before we get into Skydweller Aero's solar airplane project, I wanted to ask you a context question. Aviation accounts for between 2% and 3% of global CO2 emissions. However, it is making great efforts to decarbonize in order to reach zero emissions by 2050. How do you see this transformation? 

The transformation towards decarbonization in the aviation sector is a very important and necessary step to address climate change. It is encouraging to see that major efforts are being made to decarbonize aviation and reach net zero emissions by 2050. 

What measures are being taken in this regard?

There are several strategies in place to achieve this goal. One of them is the improvement of aircraft energy efficiency, through the incorporation of more efficient engines and improved aerodynamics. Sustainable biofuels are also being promoted as one of the most short-term measures for decarbonization, in addition to actions to reduce emissions on the ground, such as optimizing airspace, improving take-off and landing procedures, and promoting more sustainable airport infrastructures.

While a significant challenge, the transformation to decarbonized aviation is essential to moving towards sustainability. It requires close collaboration between industry, governments, research and regulatory agencies. That is why one of the motivations of the whole team is Skydweller's green, 100% sustainable and zero-emission character. 

Just a few years ago, the idea of a solar-powered aircraft sounded like science fiction. However, Skydweller Aero's aircraft has made fiction into reality. How did you venture into this project? Where did the idea come from, what inspired it? In short: what is the story behind it?

Skydweller took up the legacy of Solar Impulse, a proven Swiss platform with more than a decade of research, development and successful flight test operations. We are bringing a new life to this aircraft, making it unmanned, transforming it into the reality that is Skydweller. We put together a high-level team between Spain and the United States, with a lot of experience in the sector, and we are looking for funds and investors. From there, came the support of the U.S., French, Luxembourg and, of course, Spanish Defense Departments. And also the direct participation of the aeronautics giant Leonardo.

The size of Skydweller is smaller than that of a commercial aircraft, but could this be the starting point for applying its technology to larger ships? Or to put it another way: do you think solar energy can be part of the future of aviation?

The size of our aircraft is identical in wingspan to that of a Boeing 747. In terms of solar energy, size is important when it comes to obtaining a panel surface capable of providing the solar energy needed to close the 24-hour flying cycle. However, this aircraft weighs the equivalent of an SUV, very unique and disruptive. I always believe in ingenuity and many innovations are born when you think it is impossible. With our project, we open a path and one day maybe it can become something that has more to do with commercial aviation. 

The aircraft incorporates more than 250 square meters of photovoltaic cells that allow it to fly for 90 days without generating emissions. What have been the technical challenges in terms of adaptability, strength, weight, etc.?

It is 290 square meters exactly, and some 17,300 photovoltaic cells. The biggest technical challenge is weight and shape. If we were to use thin panels like those used for camping, for example, for our aircraft, they would weigh a ton. Skydweller weighs only 190 kilograms. And, even so, we think we can improve it.

There is another equally or even more surprising feature of the Skydweller: it operates autonomously. What challenges have you faced when applying this technology to an aircraft? What are the safety standards with respect to a manned aircraft?

The main challenge is safety, which translates into system redundancy and an understanding of all possible failure modes. From the beginning we have focused the development of the flight system on having safety standards equal or superior to those of a manned aircraft. This is the only way we can get clearance to fly over inhabited areas, and it is where experimental developers of systems similar to ours have traditionally failed in the past.

Does the autonomous piloting software also take into account factors such as efficiency, sustainability, etc.?

Absolutely. Flying our aircraft requires a high level of overall efficiency control. In other words, not only the on-board systems have to be highly efficient, but also any type of maneuvering must avoid wasting energy in order to have enough to fly all night long, since at night the solar panels do not allow us to charge the batteries.

You are the Engineering Manager on a sustainable project, what is your motivation to participate in a breakthrough that will contribute to the objective of decarbonization of the air transport sector? On a personal level, what is your vision of the global energy transformation process in which we are immersed?

My main motivation lies in innovation and the positive impact we can have on the environment and the fight against climate change: participating in a breakthrough that has the potential to significantly reduce emissions in aviation fills me with pride.

Climate change is a global challenge that affects us all and, as a professional in the engineering field, I understand the importance of addressing it urgently and decisively. Personally, I am concerned about the impact climate change is having on the planet. However, I also see it as an opportunity to drive a global transformation towards a more sustainable and environmentally friendly model. 

I firmly believe that, through innovation and collaboration, we can overcome the challenges we face and build a more sustainable future. I am committed to doing my part as the Engineering Director in a sustainable project, and I look forward to making a significant contribution to the decarbonization of the air transport sector and to the global transformation process in which we are immersed.

Since it is an aircraft based primarily on photovoltaic technology, what is your opinion on the capacity of solar power going forward? Do you think it will play a key role in the transition to decarbonization, both in the rest of the sectors and in the energy consumption of citizens? 

In my opinion, solar energy has enormous potential and will play a key role in the transition to decarbonization in different sectors. It is a renewable and widely available source in Spain that produces no emissions during operation. Although there are technical challenges to overcome, I firmly believe in the pivotal role it will play.