(about the defense, March 10)

You could call it a colorful journey – the past few years PhD candidate Catarina Simões has spent mastering harvesting energy from waters. Not only for her discoveries that made blue energy even greener but also for her experiences outside the research. Joining the personnel committee and magazine while getting her hands dirty in the lab. “I never planned to do a PhD, but the ambiance at Wetsus was the reason for me to do a PhD here.”

The person behind the science, and the science behind the person.

“I think my grandmother really awakened my curiosity about the sciences. Being a biology teacher, she would love to tell and teach me about the world. And one of these moments stuck with me was when she once showed me the working of the rabbit’s lungs. Picking up a straw and blowing air into the little lungs fascinated me,” Catarina says. And with good grades in school for the natural sciences, ending up in chemical and biochemical engineering was a logical career path.

Final destination: finishing her master’s degree in that same field with a thesis on a water-based battery. But it didn’t quite stop there. “I never planned to do a PhD, but my master thesis at Wetsus was really the reason for me to continue my studies.” And with a PhD position opening in the blue energy theme, Catarina quickly found a new challenge to work on: electrochemistry.

“After working with the water-based battery, I wanted to learn more. Understanding other electrochemical processes was the way.” So Blue energy – mixing fresh and saltwater to generate electricity – was a great fit. But a challenging one. Blue energy is one of the furthest developed techniques in Wetsus.

Catarina’s studies aimed to find the trade-off between power density and energy efficiency and enhance process sustainability. “Trying to become an expert on a topic with all other experts on the general topic around – it’s an odd start. But my mindset is to get things done today, not wait until someone else does it tomorrow.”

So that is where she started – reading up, exploring what was known, and just go for it. “But of course, you soon discover that theory and practice are not always alike.” Thus, to explore the actual value of her research, the scientist had to travel to the Afsluitdijk.

You could call it ambitious. But Catarina humbly refers to her work as ambitious but with limits. “One of the things I learned in my PhD that I’m most proud of is to keep a balance. Wetsus works nicely for that. I just couldn’t spend all evening in the lab. The technical team would only be around again at eight in the morning, so you quickly learn your effective working hours. It makes your PhD your job, not your life. And to add to that, I think the most important thing in a PhD might just be a good night’s sleep.”

Especially during COVID, as it made the research a bit more challenging. “In the end, I did get the chance to do all my experiments and take samples at the blue energy plant at the Afsluitdijk. I had a nice summer, and I could witness the real process. The more complex, differently charged salt particles, microorganisms, everything is in there. There we could figure out how swapping the fresh and saltwater streams could benefit energy generation and how we can sustainably use the expensive membranes that allow a flow of current.”

But that’s not all. Sustainability in blue energy can be improved even still. “To get electrons flowing, on a lab scale, you would use iron hexacyanide. Not the safest and most ideal compound. So, I investigated using different types of carbon to do the same job. Making black slurries that caused a mess everywhere, you’d go with them. But given the right combination, it seems a viable alternative.”

With these findings, blue energy can grow to be even greener, an even better supplement to wind and solar power. And Catarina herself? “Well, I’ve developed a bit of a love-hate relationship with electrochemistry by now. One thing is for sure, I want to make the world a cleaner place. I want to keep contributing for sustainable innovations in water, chemical and energy technologies. So water technology or sustainable technology at least seems like a place to look for.”