Harvesting Renewable Energy from the Ocean

Dr. Don Resio enjoys an engineering challenge. The bigger the problem to solve, the better. So, it’s no surprise that during his 10 years at UNF as professor of ocean engineering that Resio tackled a mystery that has remained unsolved — how to efficiently harvest green, renewable energy from the ocean.

Resio and the team of professors and students that he led have secured two patented strategies — one that uses the ebb and flow of the tides and one the power of the waves. He believes that both are capable of producing predictable and sustainable power output on a large scale under almost all conditions, with minimal negative impact to the environment.

“People around the world have been trying to harness energy from the ocean for years,” Resio said. “All of the systems have been broken by the waves. We have made sure that our systems will survive. There’s always a chance it won’t work, but theory and preliminary tests all say it will.” The next step is to work with investors to create what he calls “moderate full-scale” materials for additional testing. He plans to begin with the tidal concept.

As lead researcher of a team of six, Resio drew from 25 years of experience with the U.S. Army Corps of Engineers, where he solved many of what he called “grand challenges.” He led teams that created innovative hurricane risk assessment now used along all U.S. coastlines, as well as methods for repairing levee breaches that have improved flood mitigation around the country. These and other successes have made Resio a recognized leader in the meteorology, hydrodynamics and probabilistic analysis of environmental hazards in coastal areas.

“There were many questions on my current projects that I could answer from my work with the Corps,” he said. “In reviewing and rechecking, I’ve become convinced that both wave power and tide power are economically viable and physically viable, in other words they won’t be destroyed by storm surges or hurricanes.”

The tidal operation uses two connected waterproof bladders or rubberized containers that hold water and are lasting and durable under pressure. One will be placed on the shoreline and one offshore at a water depth of about 10 meters.

“Think of it as putting a bladder that works like bellows under the water,” Resio said. “In high tide conditions, the weight of the water pushes down on the bladder and moves the water to the other bladder, which has less water.”

As the tide ebbs to low tide, the water moves back to the bladder in the water. With this back-and-forth motion, the system converges or focuses the flow to accelerate it, which then rotates the blades of a hydro-turbine to convert the kinetic energy into electrical energy.

In comparing sources of green energy, tides are more predictable than wind or sunshine, because they never stop moving. Thus with larger and more numerous bladders, Resio believes his system can be scaled up to produce a significant portion of the energy produced by even a nuclear power plant. And once the initial investment is made, the ongoing cost of producing energy from the tides is far less than current methods.

As this project gears up, Resio is stepping down from UNF and retiring into the role of Professor Emeritus. He plans to make himself available to several of his students who have gone on for doctoral degrees. At the University, he also served as director of the Taylor Engineering Research Institute (TERI). Resio said he feels very fortunate to have been invited to head TERI by Dr. Bruce Taylor and his wife June and owes them a huge debt of gratitude for having chosen him to be the first director of this institute.

Looking back at both these roles, Resio called his time rewarding. “I came to UNF to teach students and pass knowledge on,” he said. “It’s been a spectacular experience, and encouraging students to solve problems creatively is probably the most important thing that I have done at UNF.” Shared equally with the University are the two patents that Resio and his team were able to secure. Resio himself is now president of a spinoff company and will work with his team to ensure the project moves forward. And though the energy systems might someday be profitable, he said it’s not really about the money. Instead, he repeated President John F. Kennedy’s historic words: “Ask not what your country can do for you — ask what you can do for your country.”

“At my stage in life, I want to accomplish things that make a difference,” Resio said. “I want what’s best for the world. It’s time for me to give back for all the things I’ve been able to do.”