After entering a Ph. D. program in aerospace engineering, the current of Jonathan Colby's career swept him away from aerospace and toward renewable energy. Jonathan now works to turn the flow of New York's East River into clean, renewable power. Read on to learn how blue water turns into green energy.

What is your job?

I work for a renewable energy company called Verdant Power. Our company uses the existing energy in rivers and tides to generate electricity with a machine that we developed. This machine looks like a wind turbine but it is completely submerged underwater and the movement of the water rotates the three blades to create energy. Our main project is in the East Channel of the East River in New York City. This body of water is actually a tidal strait and is full of saltwater that changes directions every six hours, so we deploy fluid turbines to generate electricity from the movement of the water. My job as a hydrodynamic engineer involves studying the water body - taking measurements from the river to understand how the water actually moves and flows in that area and helping with the design of the turbines. We also have to monitor the biology of the marine environment and the ecosystem of the river. By understanding these things we can make sure that our turbines interact with the river in a compatible way.

Why did you choose this career?

I knew I wanted to pursue engineering ever since I was in high school. I was an undeclared engineering major when I got to college and I really gravitated toward mechanical engineering for the physics and math. Within mechanical engineering I got really interested in fluid mechanics, specifically experimental fluid mechanics. I liked that with fluid mechanics the physics underlying most fluids is the same and the differences are found in their density and viscosity. I also had a major interest in astronomy and at the end of my undergraduate education I wanted to combine astronomy and engineering to do aerospace engineering. I had the opportunity to work in a lab in college doing fluid mechanics and that lead to additional work with fluid mechanics in an aerospace capacity. After obtaining a Master's degree in aerospace engineering and beginning to pursue a Ph.D. in the field, I realized that I was more interested in the field of renewable energy. When a position with Verdant Power became available I had the specific skill-set that the company was looking for. I had a pretty long background of working with fluid mechanics and Verdant happened to be looking for a hydrodynamic engineer.

Explain what an average day at work is like for you.

I have a lot of opportunities to get my hands dirty. It's almost impossible to describe an average work day because they change so much. There are some days that I spend on a barge on the water and other days I spend in a workshop physically assembling things. Some days I am in manufacturing facilities making sure that the things being built for our company are built according to our specifications, other days I am working on reports, data analysis and writing papers for publications. I also get to travel to scientific conferences and meetings to speak on behalf of Verdant. I have become personally active in the development of international standards for the marine energy industry and I do a fair amount of traveling both nationally and internationally to help develop these standards. I have been to South Korea, Australia, across a lot of Europe and across almost the entire US for work.

What do you like best about your job?

I think the best thing about my job is that I don't have an average day. I have a large amount of flexibility and I get to work from home some days as well as from different places and cities. In my years with the company I have gained a large amount of experience and insight and I feel like I am on the cutting edge of this sector of renewable energy. This work allows me to contribute positively to the world on a number of different levels.

When you were a kid, did you like science, engineering and/or math? If so, what subject did you enjoy most and why?

I have always been interested in science and engineering. I had some great teachers through middle school and high school and I was definitely convinced by the middle of high school that I wanted to pursue engineering in college. I was fortunate enough to have a trigonometry teacher/soccer coach who really encouraged me that engineering is a great outlet for the combination of math and physics. My favorite subjects were non-linear algebra, tensor mechanics and both reacting and compressible fluids.

What was the biggest challenge you faced in your journey to being a hydrodynamic engineer?

One of the biggest challenges I faced was adapting to college and learning how to live on my own during my freshman year. It was really a challenge for me to transition from living at home with my family in high school to living far away from my parents and navigating the college environment. It took me almost a year to get my feet underneath me and feel confident, engaged and successful in that environment.

Was there a person who inspired or convinced you to get involved in your field?

My soccer coach in high school was important in directing me toward engineering. Also, in my third semester at Berkley I had a wonderful connection with one of my astronomy professors. This professor actually invited me to take a follow-along course with a few other students to look at the subject in more detail. It was the first time I had been really successful in a class and really engaged with a professor, which opened up the university for me in a new way.

Do you have any suggestions for how students in elementary school can get practical experience in your field?

I think in elementary school it is important to play with things like Legos, models and other mechanical related toys. Science camps and science centers also help give an introduction to engineering. Go to science museums and try hands-on science stuff. I also really enjoyed doing science projects in school. The nice thing about pursuing mechanical engineering is that there are a lot of different fields you can work in.

Are there exciting things happening in your field that could involve children who will enter the field in 5-15 years?

Our company has huge potential for growth in the marine energy industry and I think we're not alone. We believe, and I believe, that the world is turning away from conventional fuel sources and is looking for new forms of renewable energy, such as moving water. There's going to be large growth in this industry both in the US and globally. Marine energy is a fairly new field, but the good news is that it's gaining a larger presence both domestically and internationally. There are college programs starting in the UK focusing on this discipline, so there may also be marine-energy-specific programs in the US in the future. Marine energy falls well into the larger platform of renewable energy in general.

Following my excitement and passion for doing really difficult math and science throughout my education, I've had really incredible opportunities to travel the world and engage with my counterparts from other companies and countries. These experiences have enabled me to really move into a leadership role as well. It's very satisfying to work hard and have exciting opportunities come from that hard work.

Diving Into Marine Energy:

• Hydropower has been used since ancient times to grind flour for making bread.
• Water is roughly 1000 times as dense as air.
• Approximately 40% of people on earth live within 60 mi (100 km) of water.
• The tides on earth are driven by position of the moon and sun. Differences in land formations change the length and strength of the tides at different locations on earth.
• Ocean waves are driven predominantly by wind, which itself is driven predominantly by the sun.

Green Grammar

Fluid Mechanics: The branch of physics that studies fluids (liquids, gases, and plasmas) and the forces on them.

Tidal Turbine: A device that converts kinetic energy from the tides, also called tidal energy, into mechanical energy and eventually electricity.