The oceans make up 71 percent of Earth’s surface and absorb about 30 percent of the carbon dioxide (CO2) that is released into the atmosphere. For the past 2.6 billion years, the oceans have been converting CO2 to ocean fish food (phytoplankton) through the process of photosynthesis. Now, a technology developed by Ocean-Based Climate Solutions, a startup located in Santa Fe, NM, is converting CO2 to phytoplankton using wave energy.
CEO Philip Kithil initially investigated ocean upwelling — technologies transporting deep, nutrient-rich ocean water from the twilight zone (200 to 1,000 meters deep) to the sunlit surface zone — to bring the cool deep water of the ocean to the surface with a goal to reduce the intensity of hurricanes. After multiple iterations, however, Ocean-Based decided to develop a technology that mimics nature’s upwelling and use it to stimulate life in the portions of the ocean where life is minimal.
In the oceans, nutrients needed to grow fish at the surface are trapped hundreds of meters deep. Upwelling of these nutrients is a natural process, but it only happens randomly, meaning fish growth is limited — often too little to replace the fish being caught. When too many fish are caught, their populations plummet, and natural reproduction is not enough to restore health to the ocean. Ocean-Based upwelling technology corrects this by enabling the growth of more fish.
Explaining how their technology works, Chief Engineer Philip Fullam said: “We have a buoy floating on the surface of the ocean. The buoy is attached to a long tube about 200-600m long and at the bottom of that tube is a one-way valve.”
The endless wave energy of the ocean pushes the buoy up and down. “As the wave lifts the buoy, the valve is closed, and water is pushed upward. As the wave lowers the buoy, the valve opens and refills the tube with water. It’s basically a very simple device and we are utilizing the incredible energy of the waves to generate the force necessary to charge this tube with deep ocean water,” added Fullam.
To design the device, Fullam used SolidWorks software, which allowed an iterative design process to move quickly. “If you build your model reasonably you can make a change that ripples through the model intelligently. You can do experiments that way.”
One of the key challenges, according to Fullam, is the size of the unit and getting it into the water. “A 600-m-long tube that’s 2m in diameter and weighs 5,000-6,000 lbs. — you have to figure out a way of handling that and getting it onto the boat from the shore and into the middle of the ocean and then into the ocean,” he said. “We came up with a simple spool concept. Make the buoy cylindrical and then just spool the tube onto it and then when you drop the heavy bottom weight into the water the buoy just rotates and unrolls the tube.”
The company began in 2005 and has completed over 100 days of ocean testing in the U.S., Bermuda, Peru, and Newfoundland. Recently, the team completed a deployment in the Canary Islands. “We got some really good data off that and learned a lot. We have a pretty-high confidence factor in the design, so we are working toward doing another deployment this year,” said Fullam.
The Ocean-Based team is working toward improving the MRV (measure, report, and verification) methodology for directly measuring the carbon sequestration, which, according to current science, ranges from 150 to 346 tons of CO2 per pump annually. With technology advances, the company can now estimate the new fish grown each year by each of their upwelling pumps.
According to the company, considering the high range, 100 upwelling pumps could potentially generate about 79 million lbs. of phytoplankton annually. Over time, it goes up the trophic food web, generating more plankton, small fish, which feed bigger fish, etc. At scale, the Ocean-Based technology would be a strong contributor to food security, which is already threatened by climate change owing to the migration of phytoplankton toward the poles, seeking cooler waters.
This article was written by Chitra Sethi, Director, Editorial and Digital Content Strategy at SAE Media Group. For more information, visit www.ocean-based.com .