Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!
Seawater desalination systems are gigantic, expensive, energy-sucking beasts that take up valuable space on seaside coasts. However, they are badly needed — and more of them are needed — in an era when freshwater resources are strained to the breaking point. The challenge is to get more facilities online without putting an unsustainable burden on energy systems and natural habitats, and a California startup has come up with a unique solution.
Desalination Systems Have A Problem
The seawater desalination industry has been improving its energy efficiency profile over the years, and renewable energy is opening up new opportunities for cutting carbon emissions. Cost cutting has also been a focus of attention.
Still, energy consumption looms large in the desalination field, as does the expense of building major new facilities. Exhibit A is the 11-acre, $1.4 billion, 50 million gallons-per-day desalination facility proposed for the California city of Huntington Beach. Aimed at alleviating chronic drought conditions in the region, the proposal was on the boards for 20 years before the California Coastal Commission finally ended the discussion in March of 2022.
“The long-running fight over the proposal encompasses contentious issues such as the effects on marine life, power requirements and whether the low-lying site is vulnerable to sea-level rise, as well as the company’s heavy political lobbying for the lucrative project,” noted reporter Ian James shortly before the final vote took place.
The Underwater Desalination Plant Solution
OceanWell is among the innovators coming up with solutions. As an alternative to building energy-intensive desalination plants on land at the seacoast, the company has developed a modular, pod-like structure that sits about 400 meters (about 1,312 feet) below the surface of the water.
The pods deploy reverse osmosis for desalination, a method commonly used throughout the water purification industry. In reverse osmosis, water is pushed through a semi-permeable membrane, which sorts out contaminants.
“This technology ensures ultra-clean water by filtering out salts, bacteria, viruses, pesticides, and PFAS,” OceanWell explains.
The OceanWell difference is the use of natural hydrostatic pressure — water pressure, that is — to do the pushing, rather than relying on energy-consuming pumps systems.
“Unlike traditional desalination methods that are energy-intensive and threaten marine life, OceanWell’s technology reduces energy consumption by up to 40 percent, while protecting marine life and eliminating toxic brine disposal,” the company says of itself.
In terms of brine disposal, there may be some loose ends to clear away. “Unlimited free pressure means our outfall salinity is low and environmentally benign. We disperse it through risers into deep water currents, ensuring it diffuses to ambient salinity rapidly,” OceanWell asserts. Though, that will be something for an environmental assessment to determine on a site by site basis.
15 “Water Farms” Are On The Way
Other factors in OceanWell’s favor are transportability and scalability. By scalability, they mean scalability. Each pod can deliver 1 million gallons of fresh water per day. For its first full scale “water farm,” the company is planning on a group of pods capable of delivering 58 million gallons per day, significantly more than the filed Huntington proposal.
That helps explain the interest of the US Navy. The Navy is always on the prowl for fresh water, and it has made its Deep Ocean Simulation Facility available to the company for prototype testing. OceanWell also notes that 24 state water authorities in California have joined in a working group to assist. The company is already planning to build an initial tranche of 15 water farms in the state and around the world.
Last year, the Las Virgenes Municipal Water District agreed to host a pilot test of the first “Blue Water” farm at its Virgenes Reservoir, located in the City of Westlake Village. That’s a freshwater lake, but OceanWell notes that its system can operate efficiently in fresh water as well as brackish water or seawater.
In the latest development, on November 20, OceanWell reported that it has closed on $11 million in Series A funding to take the next step and get the pilot project in motion. OceanWell lists the water infrastructure firm Kubota Corporation among the participants, along with the family office of Jon Hemingway of Carrix Ports, and Charles McGarraugh, who formerly headed up metals trading at Goldman Sachs.
The Kubota Connection
The participation of Kubota Corporation is of interest because the firm has long roots in the history of water infrastructure engineering and manufacturing, as part of the 130-year-old Kubota Group. In recent years, Kubota Group has been focusing on new solutions, and OceanWell is one of them.
“One of Kubota’s goals is to provide comprehensive solutions for the entire ‘water circulation loop’ from water production and supply to wastewater treatment and reclamation,” the company explains.
The investment in OceanWell is just one feature of Kubota’s interest. Kubota and OceanWell plan to collaborate on fine tuning the technology, with a particular focus on the pumping system.
“Given our expertise developed in advanced pump technology, we are also exploring joint development with OceanWell of long-lasting, highly reliable, and efficient pumps capable of operating under deep-sea high-pressure conditions,” Kubota explains.
Desalination Is Just The Beginning
The idea of sinking a desalination facility into the sea may seem a bit spacey on first glance, but it is of a piece with other clean tech ventures that lean on hydrostatic pressure as a form of emission-free and cost-free energy.
The US firm Sperra, for example, is participating in a multi-partner effort to develop an undersea hydrostatic energy storage system, deploying hollow 3-D printed spheres. The idea is similar to pumped storage hydropower, except that instead of using reservoirs on land, the system deploys reservoirs at sea.
The startup Ocean Grazer is also developing an undersea energy storage solution, which deploys both a bladder-type reservoir and a concrete reservoir. The aim is to co-locate the system with existing offshore wind farms or floating solar arrays. In addition to improving efficiency, Ocean Grazer anticipates a faster turnaround by locating its storage system in areas that have already been permitted for offshore activities.
As of last spring, the project is moving forward with the addition of leading engineering firm Stantec on board as a technical consultant, leveraging its extensive experience in the pumped storage hydropower field.
Circling back around to OceanWell, the firm has indicated that offshore wind resources could provide the energy required to run its pumps. Co-locating undersea energy storage systems would be a logical next step. If you have any thoughts about that, drop a note in the comment thread.
Follow me via LinkTree, or @tinamcasey on Threads, LinkedIn, and Bluesky.
Image (cropped): The US startup OceanWell is developing undersea “water farms” that leverage water pressure to operate an energy efficient desalination system (courtesy of OceanWell).
Chip in a few dollars a month to help support independent cleantech coverage that helps to accelerate the cleantech revolution!
Have a tip for CleanTechnica? Want to advertise? Want to suggest a guest for our CleanTech Talk podcast? Contact us here.
Sign up for our daily newsletter for 15 new cleantech stories a day. Or sign up for our weekly one if daily is too frequent.
CleanTechnica uses affiliate links. See our policy here.
CleanTechnica’s Comment Policy
